eChapters

Amaranthus is one of the main genera of large and taxonomically diverse group of leafy vegetables. Amaranthus is the cheapest dark green leafy vegetable because of low production costs and high yield. It is often described as poor man’s vegetable.

Origin and Distribution: The main vegetable type Amaranthus tricolor L. originated in South or South East Asia, particularly in India. Budhist monks and Muslim invaders took the crop to neighboring countries. Another vegetable type A. dubius shows diversity in Central America, Indonesia, India and in Africa. A lividus is a popular leafy vegetable in Southern and Central Europe. Amaranthus included 50 to 60 species.

Carrot (Daucus carota L.) is a cool season root vegetable and temperature is the important factor affecting root shape and colour, besides soil type and moisture content of soil. It provides an excellent source of vitamin A and fiber in the diet. The genus Daucus, which include carrot, has many wild forms that grow mostly in the Mediterranean region and South West Asia. Representatives are found in Africa, Australia, & North America. For Daucus carrot L. it is generally agreed that Afghanistan is the primary center of genetic diversity and therefore the primary source for dissemination. Asia Minor, Afghanistan, North West India, Iran and Turkey are the centers of origin of carrot. Banga (1957& 1963) has provided evidence that the purple (anthocyanin) carrot together with a yellow variant spread from Afghanistan to Mediterranean area as early as 10th and 11th century. It is known in Western Europe in 14th and 15th century, China in 14th century and Japan in 17th century. The European carrot (Carotene carrot) derived from the Asiatic (anthocyonin containing) form of carrot (tropical carrot).  Afghanistan is the centre of diversity of the purple coloured carrot (anthocyanin). Integration of Asiatic and European carrots has given the present day forms. The yellow coloured (carotene rich) forms were also thought as mutants of anthocyanin carrots. The yellow mutants were traced in Asia Minor in 10 and 11th centuries, Spain in 12th century, North Western Europe in 14th century and England by 15th century.  The crop was introduced to China during 14th century and to Japan during 17th century. D. carota and D. sativus are only cultivated species of the genera with Chromosome No. 2n = 18. All forms have same chromosome number. 

It is a popular root crop having wide range of adaptability, grown in Japan, Koria, China, India and other European countries.

Origin and Distribution: Radish was an important food in Egypt during 2000 BC.  Fossils study reveals that, it was a food as early as 2700 BC. It spread to China during 500 BC and to Japan during AD 700. Variability of crop decreased from Europe to China and from there to Japan. Recent study indicates that East of Mediterranean, most probably China was the centre of origin of the crop. This means Europe and Asia are the probable places of origin.

Beta vulgaris 2n = 2x=18 is an important vegetable crop in Eastern and Central Europe and it belongs to family Chenopodiaceae. It is of lesser importance in Western Europe and USA where it is known as garden beet. The swollen roots are consumed as vegetable and salad. The other types which are non-horticultural forms are known as sugar beet, mangold and fodder beet.
Origin: Leaf beet is the earliest domesticated form. It is believed to be originated from Beta maritima known as sea beet which is indigenous to Southern Europe. 
Botany: Biennial producing enlarged hypocotyl (roots) and rossette of leaves in first year and flowers and seeds in second year.

Turnip is the root vegetable cultivated in cooler season or temperate regions of the globe. Brassica rapa L 2n = 2x = 20 is formerly known as B. campastris subsp rapifera. Swede (B. napus var. napobrassica) is directly related to turnip.
Origin: It is originated in cooler part of Europe, presumably from biennial oilseed forms. It was known to Greeks and Romans at beginning of Christian era. It was introduced to Britain from France by Romans and into North America by the early European settlers in the 17th century.

Sweet potato Ipomea batatas(L). Lam. is an asexually propagated vegetable. It is grown in most of the tropical and subtropical region of the earth. In USA production extended to temperate regions. Vines as well as roots are eaten or fed to live stock. It is the source of industrial starch and potential source of the alcohol. Among the major tuber crops cultivated in India sweet potato rank third after potato and cassava in area and production.

Origin: Available evidence suggests South Mexico through Central America and Northern South America as the probable center of origin. It is perennial but handled as annual. Its hardiness and drought tolerance are well recognized.

Family: Convolvulaceae, Chromosome number: 2n=90

It is the only known natural hexaploid morning glory. Most of the wild species are diploid (2n=30). Hybridization is restricted with in species because of its hexaploidy nature. Extensive variability with in species is observed. Tuber is the fleshy subterranean stem or shoot but in sweet potato tuber is a root, and hence it cannot be a tuber (common error). It is a perennial, and the storage root is capable of continued enlargement and does not mature in the sense of reaching some final size or stage of development. From the stand point of function, the root system consists of absorbing roots and fleshy storage roots.

Cassava (Syn: Tapioca) Manihot esculenta (Crantz) (2n = 2x = 36) (Hindi : Mravuli) is perennial shrub cultivated in tropics for its starchy tuberous roots. It is one of important tuber crops cultivated in tropics because of its high carbohydrate yield per unit land and labour and its adaptation to poor soil and water stress and its tolerance to dominant pest and diseases. Cassava contains cyanide, the toxic principle which limits food and feed value. In cassava the glycoside linamarin and lotaustralin are converted to hydrocyanic acid, a potent toxin, when come in contact with linamerase, an enzyme that is released from rupture of cells. Tuber peel contain significantly higher amount of glycosides than the pulp. It can be removed by cooking in water for about 5 minutes.

Stem cell research is one of the most important and promising areas of research in biological science in recent times. The stem cell technology has revolutionized modern biology. It is playing a major role for improving human as well as animal health by controlling number of incurable degenerative diseases and restoration of damage to organs via transplantation therapy. Stem cells are a specific group of cells that remain in an undifferentiated state and can be found in embryos, fetuses and adult individuals. Stem cells are primitive, undifferentiated cells present in almost every tissue that have the ability to differentiate into different types of tissue like bone, tendon, ligament, cartilage etc. Bone marrow stem cell is the ideal stem cell that is unspecialized and can undergo lineage specific differentiation into bone or blood cells under different signals or environment with new special function. Several verities of stem cells have been isolated and identified in vivo and in vitro. The two broad types of mammalian stem cells are embryonic stem cells that are found in blastocyst, and adult stem cells that are found in adult tissue, bone marrow.

Mesenchymal stem cells are multipotential cells capable of proliferation and differentiation into osteogenic, chondrogenic and adipogenic lineages both in vitro and in vivo. Minimal criteria for defining MSC according to International Society of Cell Therapy (ISCT) are (a) they must be plastic-adherent when maintained in a standard culture conditions, (b) MSC must express some surface antigen such as CD105, CD73, CD90, CD44 and must not express CD34, CD45, CD 14, CD19, and HLA-DR, and (c) MSC must differentiate in vitro into osteoblast, adipocytes and chondrocytes under specific differentiating condition.

Although traditionally MSC isolated from bone marrow, more recent reports have detailed the isolation of cells with MSC characteristics from a variety of tissues including umbilical cord blood, chorionic villi of the placenta, Wharton’s jelly, peripheral blood, fetal liver and lung, adipose tissue, skeletal muscle, periosteum, deciduous teeth, amniotic fluid, dental pulp, testis, synovium and the circulatory system. Bone marrow and periosteum sources are richest in young animals with their numbers diminishing, but still present in old age. It is estimated that MSCs represent approximately only 0.01 to 0.001% of the total nucleated cells within isolated bone marrow aspirate. The yield of MSCs from bone marrow varies from species to species. e.g., Canine =1 in 2.5 × 10⁴; Feline =1 in 3.8 × 10⁵; Murine =1 in 10.8 ×10³ to 1 in 3.45×10⁴ and Horses =1 in 4.2 × 10³. Despite this low number, they are remains a great interest, as they can be easily isolated from a small aspirate and culture-expanded through as many as 40 population doublings to significant numbers in about 8 to 10 weeks.

Bone marrow contains variety of tissues including hematopoietic lineage cells and mesenchymal stem cells (MSCs). The hematopoietic cells are the major source of the blood cells in the adult body which are regulated within the microenvironment of the stromal cells of the bone marrow. MSCs are multipotent cells and can be differentiate into various cell lineage depend upon their environment and culture condition in which they are kept. Rat bone marrow derived stem cells (rBM-MSCs) have long term self renewing and capabilities of pluripotency including osteoblast, adipocytes, chondrocytes, tenocytes, muscle cells and neurogenic cells, which make them ideal source of stem cells for regeneration of injured tissue.

Bone marrow derived mesenchymal stem cells have been isolated from different species. Each species is having different culturing and growing capacity. For example human bone marrow derived stem cells are easy to harvest and maintain in culture condition whereas rat MSCs it is more difficult compared to other species. Technical difficulties in isolation limited the number of animal experiment and its required animal transplantation model for pre clinical studies. Density gradient centrifugation, plastic adherence and immunomagnetic selection like various methods are available for isolation of MSCs from bone marrow. No appropriate methods are available for selection of suitable cells. Each method has their own pros and cons. Therefore, in this chapter, combined density gradient centrifugation and plastic adherence as easy and reliable method for isolation, culture and characterization of rat bone marrow derived mesenchymal stem cell is described.

Mesenchymal stem cells are multipotential cells capable of proliferation and differentiation into chondrogenic, osteogenic and adipogenic lineages. Minimal criteria for defining MSC according to International Society of Cell Therapy (ISCT) are (a) they must be plastic-adherent when maintained in standard culture conditions, (b) MSC must express some surface antigens such asCD105, CD73, CD90, CD44 and must not express CD34, CD45, CD 14, CD19, and HLA-DR, and (c) MSC must differentiate in vitro into osteoblast, adipocytes and chondrocytes under specific differentiating condition. 
Although MSC is traditionally isolated from bone marrow, more recent reports have detailed the isolation of cells with MSC characteristics from a variety of tissues including umbilical cord blood, chorionic villi of the placenta, Wharton’s jelly, peripheral blood, fetal liver and lung, adipose tissue, skeletal muscle, periosteum, deciduous teeth, amniotic fluid and synovium. Bone marrow and periosteum sources are richest in young animals with their numbers diminishing, but still present in old age. One of the attractive advantage of bone marrow derived mesenchymal stem cells (BM-MSCs) as a source of cell transplantation is their low immunogenecity. Recently, several studies have reported that BM-MSCs may be immune-privileged cells that do not elicit immune response due to an absence of their immunologically relevant cell surface markers. BM-MSCs also are known to inhibit proliferation of T lymphocytes, B lymphocytes, dendritic cells and natural killer cells.

The knowledge and principles from interconnected disciplines of bioengineering, material science and life sciences are combined in tissue engineering with the aim of developing a construct that can wholly or partly restore/maintain/augment the function of a damaged tissue or organ. Tissue engineering construct generally comprises cells on a suitable scaffold. The ultimate functionality of a tissue engineering construct is mainly dependent on the cell behavior on scaffolds. The proliferation and cell viability on scaffolds varies from one cell type to another and from one species to another. So it is important to investigate individual cell-scaffold combinations.

The similarity in structure and composition to bone mineral, osteoconductive properties, ability to integrate with the bony tissue and absence of immune response makes hydroxyapatite [Ca10 (PO4)6(OH)2] the choice of calcium phosphate biomaterial with only disadvantage of slow rate of resorption. On contrary, silica–calcium phosphate composite in comparison to calcium phosphate is rich biomaterials having a faster resorption rate. Studies have shown that coating of hydroxyapatite with a calcium silicate containing layer encourages cell proliferation and osteogenic differentiation of human bone marrow-derived stromal cells.

In this chapter a composite scaffold (calcium silicate, hydroxyapatite and tricalcium phosphate), namely HASi with elements in the following percentages: 66.36 % - calcium, 25.35 % - phosphorus and silicon - 8.29 % and porosity of 50 – 500 µm is undertaken to evaluate the rBMSC proliferation and differentiation properties in vitro with the aim of assessing cytocompatibility of HASi and rBMSC in terms of cell attachment, cell morphology, cell proliferation and osteogenic differentiation.

Fracture healing is a complex process in which damaged bone restores its original architecture through a cascade of molecular and cellular events. The process of fracture healing is unique, in that it does not form a poorly organized replacement matrix, otherwise known as scar tissue, but rather regenerates the original matrix and retains its mechanical properties. Normal fracture and bone repair follows a known sequence of events includes: haematoma formation, inflammation, angiogenesis, osteogenesis, and bone remodeling.

For the repair of bone defects, a tissue engineering approach would be to combine cells capable of osteogenic (i.e. bone-forming) activity with an appropriate scaffolding material to stimulate bone regeneration and repair. An ideal tissue-engineered bone substitute should possess 3 elements: osteoprogenitor cells, osteoinductive factors, and an osteoconductive scaffold, and is considered as a potential substitute for autologous bone transplantation. Tissue engineering approaches have proven very effective in bone regeneration recently, and the successful repair of bone defects has been demonstrated in larger animals like canine, goat and sheep.

Stem cells from adult tissues are attractive materials for cell therapy, gene therapy, and tissue engineering. These cells generally have restricted lineage potential when compared to embryonic stem cells, and this may be advantageous in certain therapeutic applications. Till and McCulloch in 1961 describes the presence of hematopoietic progenitor cells in bone marrow. After this, the concept of MSCs is brought to light by Friedenstein and co-workers who demonstrated the osteogenic potential of BM cells by heterotrophic transplantation.

Despite the benefits that minimally invasive surgery and osteosynthesis have brought to fracture management and bone healing, there are still many circumstances where bone healing remains challenging. Large bone defects are serious complications that are most commonly caused by extensive trauma, tumour, infection, or congenital musculoskeletal disorders. In nonunion cases repairing of bone defects with composite biomaterials as defect filler can promote bone regeneration. Currently, the gold standard for bone regeneration is use of autogenous bone graft. In order to avoid morbidity at the donor site or if large amount of autogenous bone is needed, bone substitution materials can be used.

Bone substitution materials can be combined with cells such as mesenchymal stem cells (MSCs) to increase bone formation. Bone-marrow derived mesenchymal stem cells (BMSCs) represent an attractive cell population for tissue regeneration. Bone marrow stem cells are pluripotent cells that have been used to facilitate bone repair because of their capability of differentiating into osteoblasts. Several studies on the regeneration of bone have shown that cultured BMSCs, seeded on different bioabsorbable implants are able to induce bone formation in vivo and lead to improved healing of critical-size defects.

Disruption of the cellular or anatomical continuity of the normal organ structure is known as wound. Healing involves migration, infiltration, proliferation and differentiation of several cell types like keratinocytes, fibroblasts, endothelial cells, macrophages, and platelets which are culminate as an inflammatory response, new tissue formation and wound closure. Healing of the wound starts from the moment of the injury and can continue for varying periods of time depending on the extent of wound. The process of wound healing involves coagulation, inflammation, formation of granulation tissue, matrix formation, remodeling of connective tissue, collagenization and acquisition of wound strength.

Chitosan is a -1, 4-linked polymer of glucosamine (2-amino-2-deoxy—D-glucose) and lesser amounts of N-acetylglucosamine. It is a derivative of chitin (poly-Nacetylglucosamine) which is the second most abundant biopolymer after cellulose. Chitosan is first discovered in 1811 by Henri Braconnota, a French chemist and pharmacist. Later in the century, chitin is found in crustaceans (such as crabs, lobsters, shellfish and shrimp). Chitosan is a biodegradable polymer and it accelerates wound healing. It has been reported that chitosan permits regeneration of tissue elements in skin wounds and has positive application effects on wound healing.

The cornea is the anterior transparent part of the fibrous tunic of the globe which has both mechanical and optical function. It functions to support the intraocular contents and transmit and refract light. Histologically, the cornea is composed of an outer stratified squamous corneal epithelium and its basement membrane, an underlying collagenous stroma, a thin acellular membrane, and an inner monolayer of cells, the corneal endothelium. In dogs, the central cornea is thinner than the peripheral cornea, whereas regional differences in thickness may not exist in cats. The active pumping mechanism of corneal endothelium and the barrier function of anterior epithelium keep the cornea in a state of relative dehydration. Compromise of either of these mechanisms will allow corneal edema to develop, with a concomitant increase in corneal thickness. Corneal ulceration is one of the most common ophthalmic disorders in veterinary medicine. Corneal ulcers are classified based on depth and ease of healing. There are several phases during the corneal epithelial wound healing process, including a lag phase where cells alter their metabolic status; a migration phase to cover the bare surface; a proliferation phase and a differentiation phase, where cells stratify and re-establish multiple layers of distinct cells. Methods of surgical treatment for canine corneal ulcers include temporary tarsorrhaphy, third eyelid flap, conjunctival pedicle graft, tissue adhesive, corneo-scleral graft and transplantation of natural or synthetic material.

Full thickness burn wound will not heal spontaneously which need early excision and adequate coverage to prevent fluid loss and risk of infection. Major portion of the skin is lost during burn injury which is the active layer for protecting the entry of micro organism from outside environment. So far, meshed autologous skin graft is regarded as the gold standard for treating extensive full thickness burns. However, their frequent use may be hampered by several impediments such as limited availability, donor site morbidity, associated with additional scarring. Severe burn patients invariably lack additional skin donor site. Moreover, creation of donor site in burned patient is equivalent to second degree burn and which further increase the total body surface area affected (TBSA). In past decades, numerous biomaterials have been investigated for the use as a dermal skin substitute for burn patients but none give promising results. The innovative tissue engineered bioactive materials offer potential tissue regeneration and prevent the tissue deterioration.

The extracellular matrix (ECM) derived naturally from mammalian tissue have been successfully used as scaffold for tissue reconstruction and wound management in clinical applications. ECM can be derived from various tissue or organs of different species but most commonly, porcine small intestinal submucosa and urinary bladder have been successfully used as scaffold for reconstruction. ECM is obtained by process of decellularization that involves the use of various ionic and non ionic detergents, acids, enzymatic solutions and mechanical/physical methods.

Burn wounds are considered to be one of the most devastating kinds of trauma that affect the physical, physiological and psychological well being of an individual. Based on the depth of the affected area, burn wound is divided into three categories: first degree (superficial), second degree (partial) and third degree (full thickness). Extensive and deep burns result in scar formation and subsequent deformation of the affected part. Healing of burn wound involves several interrelated and overlapping stages such as inflammatory, proliferative and remodeling phases. The interaction of a variety of mediators, cells and extracellular matrix proteins are involved in this three phases of healing.

Burn wound therapy has been performed in various ways such as bioengineered skin grafts and administration of growth factors. Small intestinal sub-mucosa (SIS) is a resorbable xenogenic bioscaffold that has induced constructive remodeling in variety of animal models. It is unique from other acellular matrices as it contains few growth factors such as fibroblast growth factor (FGF) and transforming growth factor (TGF) that play a role in the regenerative process. Chitosan is currently proposed to be one of the most promising polymers in wound dressing development and it accelerates wound healing. Epidermal growth factor is known to stimulate growth of keratinocytes in vitro, thus it might be expected to promote wound healing.

In this chapter efficacy of Chitosan and porcine acellular small intestinal sub-mucosal (SIS) matrix seeded with bone marrow derived mesenchymal stem cells (BM-MSCs) and recombinant murine epidermal growth factor (m-EGF) on healing of full thickness burn wound in rat model is described.

The liver is an organ that plays a central role in maintaining metabolic homeostasis, in its functions of metabolism, synthesis and storage of nutrients. The cells in the liver are parenchyma cells and non- parenchyma cells. The former include hepatocytes (80% of the cell population) and the later includes endothelial cells, Kupffer cells, lymphocytes and stellate cells. Liver dysfunction or failures are having different etiologies. Liver cancer has the fifth highest cancer incidence in the world, and is the third highest cause of cancer related deaths, with resection of the liver remaining the only curative option.

Following liver injury, the repair process involves two distinct phases: a regenerative phase, in which injured liver cells are replaced with regenerated hepatocytes; and a phase known as fibroplasia or fibrosis, in which connective tissue replace normal parenchyma tissue. The process even though initially beneficial becomes pathogenic when it is not controlled appropriately. Extensive accumulation of extra-cellular matrix (ECM) components ultimately leads to cirrhosis and liver failure. Thus, the ideal strategy to treat liver injury is to generate new hepatocytes replacing damaged cells without causing excessive ECM deposition.

Bone is the only tissue in the body able to heal without microscopical scarring. On the other hand fracture healing is a slow process causing long immobilization periods with consequently high costs for fracture healing giving rise to delayed healing, fibrous healing or non-healing with subsequent problems for both, the patient and the orthopedic surgeon. Fracture healing is complex phenomenon which involves numerous cells, regulators of cell function and biochemical interactions in the repair process. The healing potential of bone, in a fracture model is influenced by a variety of biochemical, biomechanical, cellular, hormonal and pathological mechanisms. A continuous occurring state of bone deposition, resorption and remodeling facilitates the healing process.

Biodegradable and bioinert ceramic materials such as hydroxyapatite (HA), tri­calcium phosphate (TCP), aluminum-calcium-phosphate (ALCAP) ceramics provides scaffold to support the attachment and migration of newly formed bone cells into the osseous defect and also help in formation of a vascular network through the newly formed bone. Bioceramic also act as a carrier to deliver stem cells for osteogenesis.

Specific bone-inductive proteins/growth factors can induce bone formation and healing in vivo. These morphogens are therefore, to be an ideal alternative to autogenous bone grafts. These findings initiating intensive research into bone regeneration orchestrated by putative soluble signals and lead to the discovery and identification of an entirely novel family of protein initiators collectively called the bone morphogenic protein (BMPs), which belong to transforming growth factors-ß (TGF- ß) super family. These growth factors might possess a biological activity that is site and tissue specific in the induction of bone formation. Different growth factors have been demonstrated to possess osteoinductive and fracture healing properties.

Collect the femur and tibia and clean them very well from blood, tendons, muscle, skin and other tissues (using scalpel)

Cut off epi-and metaphysis from the long bones with electric/manual bone saw
Transfer the open bones to a falcon tubes containing cell culture medium/DPBS without FBS but containing 1% PS (Penicillin-streptomycin)
Transfer the bones to a Petri dish containing 5 ml medium without serum (FBS) and without antibiotic (40-50 mm Petri dish)
Remove the pteri dish to the laminar cabinet
Collect the bone marrow by flushing out to a 50 ml falcon tube (use syringes and needles to flush out the bone marrow; flush out the bone marrow with complete (10% FBS, 1% PS, 90% DMEM-LG) culture medium
Centrifugation: 300rpm, 8 min (in the meanwhile prepare 5 ml of Ficoll into a 15ml falcon tube)
Aspire the medium

1.    Collect fat tissues from euthanized animals into a Falcon tube containing DPBS + 1% PS ( for transferring lab to lab)
2.    Wash 3 times with DPBS + 1% PS
3.    Inside a laminar cabinet, transfer the fat to a Petridis (use an sterile spatula to collect the fat)
4.    Cut the fat into small (mm) pieces using scalpel and forceps or scissors
5.    Transfer the fat into a Falcon tube (eg into a 50 ml Falcon tube you can add upto 10 ml fat tissues)
6.    Wash the fat by adding approx 40 ml DPBS; Centrifugation: 430g, 10 min (without break)
7.    Transfer the fat into a fresh 50 ml Falcon tube (with the help of sterile spatula); Repeat steps 5 to 7 for 2-3 times

1.    Collect the bone marrow from iliac crest of rabbit, dog, goat and sheep; sternum of pigs by 16-18 G bone marrow biopsy needle under sedation/anesthesia and maintain strict asepsis protocol
2.    To aspirate bone marrow, negative pressure should create in the syringe by pulling back the plunger. Syringe should be first flushed with heparin before bone marrow collection
3.    Collect approximately 2.5-5 ml of bone marrow from each animal
4.    Mix the bone marrow sample with equal volume of low DMEM having 10% FBS and 1 ml of PS and then layer on 5 ml of histopaque/Ficol-Paque Plus in a falcon tube
5.    Centrifuge at 3000 rpm for 30 min
6.    Collect stem cells from the interface with the help of a micropipette
7.    Cells wash thrice with DPBS 
8.    Centrifuged at 2000 rpm for 5 min

1.    Remove the growth media
2.    Wash 2 times with warm PBS (w/o Ca and Mg)
3.    Add 5ml of trypsin /EDTA 0.35 % (Invitrogen), place at 370C in a CO2 incubator for 4-5 min
4.    Wait until cells are detached/lifted and make sure by examining on microscope
5.    Add equal volume (5ml-1:1) of growth medium as appropriate and mix with 5 strokes
6.    Transfer into 15 ml centrifuge tube
7.    Centrifuge at room temperature for 4 min in 980 rpm
8.    Remove supernatant complete but carefully without touching the cell aliquot
9.    Re-suspend in 10ml DPBS (with Ca and Mg)-5 strokes
10.    Immediately after mixing transfer 100µl of cell suspension into Casy vial, containing 10ml Casyton

Downy mildew is refered to a condition of plant disease where the fungal growth and infection appears on the dorsal side of the leaf surface while the corresponding ventral side of the leaf shows faint yellowish color. It is also refered to the fungus which causes this disease.The word mildew in Latin language means mil + dew i.e honey like dews.The fungal growth on plant surface resembles to the milky dews in the beginging which turn to golden brownish honey like dews in later stage. Subsequently the affected areas turn grayish brown and dry. Besides the infection of leaves, the fungus also infects the fruits. The downy mildew infection on fruits causes the deformities on the affected fruits. The infection of the downy mildew pathogen on some of the cereals like pearlmillet causes the symptoms like green ear disease .

Downy mildew pathogens can cause major damage in the nursery, in greenhouse, in field crops and in landscape in the form of leaf spots, blights, and distortions with mildew growth. Downy mildews are primarily foliage blights with mildew growth of the fungus on affected portion. The fungus attack and spread rapidly in young, tender green leaf, twig, and fruit tissues. The fungal development are severe when a film of water is present on the plant tissues and the relative humidity in the air is high during cool or warm, but not hot, periods. Downy mildews can cause severe losses in short periods of time. Downy mildews often cause rapid and severe losses of young crop plants still in the seedbed or in the field. They often destroy from 40 to 90% of the young plants or young shoots in the field, causing heavy or total losses of crop yields. The severity of loss depends on the prolonged presence of wet, cool weather during which the downy mildews fungus sporulate profusely, cause numerous new infections, and spread into and rapidly kill young succulent tissues.

2.1. Downy mildew of Sorghum
Pathogen: Peronosclerospora sorghi (W. Weston & Uppal) C.G. Shaw, (1978)
Host plants
Major hosts: Sorghum bicolor (sorghum), Sorghum caffrorum, Sorghum Sudanese (sudan grass), Zea diploperennis, Zea mays. 
Minor hosts: Andropogon sorghi, Panicum trypheron, Pennisetum glaucum (pearl millet), Sorghum halepense (Johnson grass), Zea mexicana (teosinte) 
Geographic Distribution
It is found worldwide in tropical and subtropical regions. Sorghum downy mildew is widely distributed in following countries.
Asia: Bangladesh, China, India, Iran, Israel, Japan, Nepal, Pakistan, Philippines, Thailand and Yemen (CMI, 1988; Jeger et al., 1998).In India though the losses are reported from the states of U.P. and Madhya Pradesh, the disease is very common and destructive in Karnataka, Tamil Nadu, Andhra Pradesh, and Maharashtra

3.1. Downy mildew of peas
It is an important disease of pea crop particularly in those areas where cool and wet climate is prevalent during its cultivation. The disease during favourable weather conditions causes considerable yield losses.
Pathogen: Peronospora viciae (formerly P. pisi)
Host range
Vigna faba, Vigna sativa. Pisum arvensis, P.sativum, Lathyrus sativus, Vicia hirsuta, Vicia sativa, Vicia villosa (Dixon, 1981).
Geographical distribution
Reports of the pathogen are from different countries on different crop host.
On Pea- Berkeley in England first discovered the disease in 1846 (Chupp and Sherf, 1960) and since then it has been found in all parts of the world where the crop is grown intensively. The occurrence of the disease has been reported from Argentina, Australia, Canada, Chile, Denmark, France, Germany, Kenya, Netherland, New Zealand, Rhodesia, Spain, Tasmania, USA, Ukrain, Italy, Poland and Australia (Dixon,1981). In India it is prevalent in Indogangetic plains including Uttar Pradesh and Punjab (Bains and Dhaliwal, 1986).

4.1. Downy mildew of sunflower

Pathogen: Plasmopara halstedii (Fort.) Berl.& de Tom.

Hosts

Over 100 host species from a wide range of genera in the family Asteraceae have been reported susceptible to this pathogen, including wild and cultivated species of Helianthus, e.g. sunflowers, which is the principal economic host. Wild Asteraceae hosts (e.g. species of the genera Helianthus, Artemisia, Xanthium, etc.) may also occur widely in the corresponding areas but their potential as reservoirs of the pest is not yet known (Virányi, 1984). For lists of hosts see Leppik (1966) and Novotel’nova (1966).

Geographical distribution

EPPO region: Present wherever sunflowers are grown, in Albania, Austria, Bulgaria, Czech Republic, Egypt, Estonia, France, Germany, Hungary, Italy, Moldova, Morocco, Poland (unconfirmed), Romania, Slovakia, Spain, Switzerland, Turkey, Russia (European, Siberia), Ukraine and Yugoslavia.
Asia: Azerbaijan, China, Georgia, India, Iran, Iraq, Israel, Japan, Kazakhstan, Pakistan, Russia (Siberia), Turkey. 
Africa: Egypt, Ethiopia, Kenya, Morocco, Zimbabwe, Uganda.

5.1 Downy Mildew of hemp

Pathogen: Pseudoperonospora cannabina

Geographical distribution
 
It’s spread has been limited to Asia and Europe.

Symptoms

Downy mildew begins as yellow leaf spots of irregular size and angular shape, limited by leaf veins. Opposite the spots, on the underside of leaves, the fungus emerges from stomata to sporulate. Mycelial growth on the underside of leaves is best seen in early morning when dew turns the mycelium a lustrous violet-grey colour (Fig 5.1). Lesions enlarge quickly and affected leaves become contorted. Leaves soon become necrotic and fall off. Whole plants and entire fields may follow this pattern.

6.1. Downy mildew of Sugarcane

Pathogen: Sugarcane downy mildew can be caused by four species:

    1)    Peronosclerospora sacchari
    2)    P. miscanthi
    3)    P. spontanea and
    4)    P. philippinensis

Major Host
Hosts in the Saccharum genus include: S. officinarum, S. robustum, S. spontaneum and S. edule.

Minor Host
Other hosts include Zea mays (maize), teosinte (Euchlaena mexicana), Sorghum halapense (Johnson grass), S. sudanense (Sudan grass), Tripsacum dactyloides (Gama grass), Sorghum bicolor (broom corn). Other studies suggest there are 18 species that are systemically infected in the sub-family Panicoideae; these include species of Andropogon, Bothriochloa, Eulalia, Schizachyrium and Sorghum (Bonde & Peterson 1981)

Geographic Distribution
The disease is restricted to the Pacific, South Asia and South East Asian regions viz Fiji, India, Indonesia, Japan, Papua New Guinea, Philippines, Taiwan and Thailand (Suma & Magarey 2000).

7.1 Downy mildew of grape
Pathogen: Plasmopara viticola

History and Epidemics
In France downy mildew is called as “le mildiou” while in Germany it is called as “falscher Meltau”. Downy mildew is undoubtedly of American origin and was probably indigenous on the wild grapes of the eastern United States, from which it spread to the cultivated vineyards when these were established by the colonists. It was not known to occur outside America until 1870, although it was first described from this country as early as 1834. In the early part of the last century various horticultural writers referred to the destructive action of the mildew on cultivated grapes.
Its history in Europe dates back to the time when French vine-yards were suffering from the grape Phylloxera, an aphid insect pest that was also introduced into Europe from America. It was found that rootstocks of the American species were more resistant to this aphid than was the European vinifera grape, and therefore consequently around 1870 importations of the American Vines were made into Europe, and somewhere around 1875 the downy mildew fungus evidently was also introduced with these importation and became established, and by 1878 it was prevalent enough to cause alarm. Since the European vinifera grapes were far more susceptible to this disease than were the American species, it soon became a real menace to grape culture throughout the humid sections of Europe.

8.1. Downy mildew of cruciferous vegetables

Cruciferous vegetables are important Kharif vegetable crops, which are grown both for table and seed purpose. This vegetable group constitutes crops like cauliflower, cabbage, radish, turnip, broccoli, brussel’s sprouts; knol-khol and rutabaga .The vegetable crops affected by downy mildews pathogen Peronospora parasitica are members of the genus Brassica and the downy mildew diseases on these crops are widespread in those regions of the world, which have cool and wet climate.

Geographical distribution

The downy mildew disease on cruciferous crops has worldwide distribution. The disease was first recorded in 1883 in USA on Brassica spp. (Farlow, 1883). In India, this disease was first reported by Butler in 1918. Subsequently various authors reported this disease from many countries of the world (Channon, 1981) particularly Angola (Serafim and Serafim, 1968), Argentine (Lindquist, 1939), Australia (Samuel, 1925; Anon., 1955), Austria (Glaeser, 1970), Bermuda (Waters-ton, 1940), Brazil (Grillo, 1937), Britain (Moore, 1959), Brunei (Herb. IMI), Canada (Jones, 1944; Downey and Bolton, 1961), Chile (Mujica and Vergara, 1960), China (Porter, 1926; Pai, 1957), Columbia (Orjuela, 1965), Costa Rica (McGuire and Crandall, 1967), Cuba (Fernandez Rosenada, 1973), Cyprus (Herb.IMI), Czechoslovakia (Rydl, 1968), Denmark (Gram and Rostrup, 1924), Dominica (Anon., 1972a), Egypt (Elarosi and Assawah, 1959), Ethiopia (Herb. IMI), Fiji (Anon, 1969), Finland (Herb. IMI), France (Darpoux, 1945), Germany (Neumann, 1955), Greece (Herb.IMI), Guatemala (Muller, 1950), Haiti (Anon., 1972a), Hong-Kong (Johnston, 1963), India (Thind, 1942), Iran (Ershad, 1977), Iraq (Herb.IMI), Israel (Peleg, 1953), Italy (Ciferri, 1961), Jamaica (Leather, 1967), Japan (Hiura and Kanegae, 1934), Kampuchea (Soonthronpoct, 1969), Kenya (Anon., 1957), Korea (Anon., 1972b), Libya (Herb.IMI), Malawi (Peregrine and Siddiqi, 1972), Malaysia (Mcintosh, 1951), Malta (Herb.IMI), Mauritius (Orian, 1951), Mexico (Rodriguez, 1972), Morocco (Herb. IMI) , Mozambique (Decarvalho, 1948), Nepal (Bhatt, 1966), Netherlands (Thung, 1926b), New Zealand

9.1. Downy mildew of Opium poppy
Pathogen: Peronospora arborescens (Berk) de Bary

Geographical distribution and losses
This is one of the serious and widespread diseases of opium poppy. The disease was observed epiphytotic in Argentina, Germany, Iran, Hungary, Austria and India. The disease was first recorded in India in 1918 and with the introduction of susceptible varieties, the disease rapidly became serious due to favourable environment in its cultivation area in India. Downy mildew now occurs in most regions in India (Rajasthan, Madhya Padesh and Uttar Pradesh). Downy mildew caused 20-30% loss of yield of opium latex. The secondary infection of downy mildew was found to reduce 11-22% latex.

Symptoms
The infection spread upwards from lower leaves. The entire leaf surface is covered by downy mildew coating, which is composed of sporangiophores and sporangia of the pathogen (Fig 9.1). The stem, branches and even capsules are attacked resulting in the premature death of the plants. The infection start from the moment the seed germinate and persist during the whole period of growth (Yossi fovitch 1929). Khristov (1943) reported that the pathogen often cause abnormal development in opium poppy. The pathogen also causes hypertrophy and curvature of stem and flower stalks.

10.1. Downy mildew of Plantago psyllium

Downy mildew is the major and serious disease of Plantago particularly P. ovata. It causes enormous quantitative and qualitative loss and often becomes a limiting factor in the successful cultivation of the crop (Desai and Desai, 1969). Usually the disease appears at the time of spike initiation.

Pathogen: Peronospora alta and P. plantaginis

Geographical distribution
Plantago ovata under commercial cultivation has been reported to suffer from downy mildew disease. Downy mildew occurs on ripe seeds of Spanish, French and European plantago. The downy mildew is a native of Mediterranean region especially Southern Europe, North Africa and West Pakistan.
The plantago commercially cultivated in Gujarat and to a limited extent in Haryana and Rajasthan provinces in India is observed to be infected with downy mildew.

Downy mildew has been reported on a wide range of ornamentals, especially those in home gardens, but only in a few instances the diseases have been sufficiently severe and widespread .Generally the diseases have been of most concern in a few ornamentals grown as crops either out doors or under glass or in nurseries, where many seedlings are raised in close proximity, often under humid conditions which favour this disease. Downy mildew having importance on ornamentals and flowering plants are:

11.1. Downy Mildews of Anemone (Windflower)

Two downy mildews are reported on cultivated anemones. The one is caused by Plasmopara pygmaea while the other is caused by Peronospora sp.
Pathogen .1. : Plasmopara pygmaea
It was first recorded in Britain on decaen anemones near Liskeard, Cornwall, in september 1917

Symptoms
It causes blackening of the foliage of the planting. The sporangiophores emerged from stomata at the periphery of the blackened zone. The fine white mildew covers the under surface of the leaves. Plants become discolored with aborted stamens. Oospores are found in the discolored tissues.

India is the second most populous country in the world with a population of 1.3 billion and is expected to reach 2 billion by 2050. Though the country transformed itself from a food deficit nation to surplus donor in agricultural commodities in a short span of 70 years, it also encountered several stumbling block along the way. In post independence era, the governments of the day adopted a multi-pronged strategy of population control, development of irrigational infrastructure, high yielding varieties of crops and agricultural development schemes that resulted in green revolution, white revolution, rainbow revolution. etc., which saddled the country in a comfortable position as far as food production is concerned. In the process, what went unnoticed was the hidden hunger resulting in malnourished population with different kinds of ailments. ‘Hidden hunger’ manifested due to an imbalanced diet, lacking in micronutrients–vitamins, minerals and other essential diet components. Serious among them, which plague the country even today are iron deficiency causing anaemia, Vitamin A deficiency (VAD) causinig blindness in children and increased risk of other illnesses and death. Anaemia and calcium deficiency among women and stuntend growth in children are the other diet related diseases. About 10% of population are also suffering due to over feeding or mal-noursihment. Economic burden and loss of human productivity due to lifestyle diseases is taking a toll in India during the last couple of decades.

At present, the world can very broadly be divided into two main categories. (i) Industrialized countries where food is plentiful and the diet is varied, and the most prevalent diet-related disorders are cardiovascular disease (CVD), cancer, obesity, diabetes and osteoporosis. (ii) Developing countries, where food is scarce and malnutrition is a major problem or where traditional foods and cultural practices are being replaced by western-style diets resulting in lifestyle diseases/disorder. India falls in the second category. Diversified food habit is one of the direct impacts of increasing disposable income in India. Global epidemiological studies with reference to food habits have shown that increase in lifestyle diseases are directly related to reduced consumption of fruits and vegetables and increased consumption of animal food (meat and animal fat).

Food, Water and Air are three essential elements for existence and sustenance of life. Primarily food is manufactured by the plants by trapping the energy of Sun in presence of carbondioxide and water. Foods can be broadly classified into energy foods and protective foods. While energy is required for all bodily functions, protective foods confer a degree of resistance against diseases, corrects some disorder and prevents occurrence of certain conditions that occur due to deficiency of certain elements and phytochemicals. The balanced diets are said to be those which have an appropriate amount of carbohydrates, proteins and fats. All these three components play certain essential role in the process of metabolism. Deficiency or insufficiency of these major food components may lead to energy deficient disease conditions and are considered responsible for malnutrition world wide. Energy deficiency can threaten the existence of life. Food grains, tubers and roots are major sources of carbohydrates, and proteins. Sufficient intake of carbohydrates, proteins and fats alone does not ensure health. Health and wellbeing are the two important aspects of life, which makes it worth living. For being healthy, besides energy, body requires minerals and vitamins which are present mainly in fruits and vegetables. The role phytochemicals play in cleansing the body and fight against diseases, was understood quite recently. Therefore, for a healthy life we need to consume a balanced diet comprising of appropriate amounts of carbohydrates, proteins, fats, fruits, vegetables and nuts. While the former three can be consumed based on the energy requirement of an individual, one should consume at least 180 and 300 grams of fruits and vegetables respectively everyday.

Fruits have been one of the earliest foods of mankind. Ancient Indian texts like Charak Samhita and Sushruta Samhita, religious books and puranas are replete with mention of various kinds of fruits. The mango is believed to have been grown for more than 4000 years. Mention of apple, the forbidden fruit, in the Holy Bible is well known. The date-palm is recorded as the fruit crop grown by mankind since 7000 BC. The first book in the world on fruit culture is said to have been the one written on litchi in 1056 AD. In the earlier period of human civilization, fruits served both as food and medicine. Fruits, nuts and tubers were the staples for early wanderers and gatherers. The settled agriculture made mankind more dependent on cereals, pulses and oilseeds for staples and fruits, vegetables and nuts became more a medicine than food.

Many evolutionary and anthropological changes occurred in course of time with changing food habits. At every stage of major change, food habits determined the life expectancy. After completing a full cycle or helix, time has returned to focus on fruits and vegetables again as food, from a stand point of health and wellbeing. From being trees of wild and forests in earlier period, fruit crops became confined to palaces and orchards of Kings in medieval period. In modern Era, it came to stay as commercial commodities dictating the terms of trade. Due to its growing commercial importance the governments across the globe focused to expand the area under fruit crops and cross border trade in several fruits and vegetables. Horticulture research started prioritizing the traits in fruits that determine the economics of trade. In line with these developments, Indian government assigned great significance to horticultural crops since 8^th five-year plan period, and the allocation for horticultural research was increased to `110.2 crores from `31.96 crores in the previous plan. During the 10^th five-year plan period in 2005-06, the National Horticulture Mission was started. As the net outcome of these efforts, the area under fruit crops increased from 2.87 million ha in 1991-92 to 6.48 million ha in 2016-17. The production increased from 28.63 million tonnes to 92.85 million tonnes and productivity from 9.96 tonnes/ha to 14.33 tonnes/ha during the same period (Anon, 2017).

Out of the total value of output of agricultural crops, fruits and vegetables contribute the lion’s share of 23%. The major fruit crops producing states are Andhra Pradesh, Maharashtra, Uttar Pradesh, Gujarat, Madhya Pradesh, Karnataka, Tamil Nadu, Bihar, West Bengal and Chattisgarh. The major fruit crops grown are banana, mango, citrus fruits (sweet orange, mandarin, lime & lemons), peach, guava, papaya, pomegranate, sapota, apple, pineapple, ber, litchi, avocado, etc. Several minor crops like jackfruit, aonla, bael, jamun, custard apple, fig, karonda, phalsa, carambola, etc., are also grown. Some exotic fruit crops like dragon fruit, kiwi, durian, Malayan apple, rambutan, etc., are also getting imported either due to its extra ordinary taste or exotic flavor.

Aonla is said to be indigenous to tropical south-eastern Asia, particularly in central and southern India (Firminger, 1947). The genus comprises of about 350 species. It is also called Indian gooseberry, amla, nelli, myrobalan, amlaki, amali, ambala, amlika, sirikai, amalakamu in different regional languages in India. Aonla is one of the richest sources of natural ascorbic acid which is protected by high polyphenols content during storage and processing. Aonla is indigenous to central and southern India. It is found it Sri Lanka, Malaysia, China and Malacca. In India, it is widely cultivated in Uttar Pradesh, Tamil Nadu. Madhya Pradesh, Rajasthan, Gujarat, Chhatisgarh and Jharkhand.

Cultivars/Varieties: Some of the well-known improved varieties are Banarasi, Chakaiya, Krishna (NA-5), Kanchan (NA-4), Hathi Jhul, Neelam (NA-7), Amrit (NA-6), Balwant, Anand-1, 2 & 3.

Uses

The fruit is widely used in ayurvedic preparation due to its pharmacological properties. The fruits are made into preserve (murabba), sauce, candy, dried chips, etc., Fruits are pickled and made into, jelly, toffee, etc., bark and leaves are used for tanning and wood is used for preparing hookah.

Apple is the pomaceous fruit (Malus domestica) in the rose family (Rosaceae). It is one of the most widely cultivated tree fruits, and the most widely known of the many members of genus Malus that are used by humans.

The apple originated in South-West Asia which includes Asia Minor, the Caucasus, Soviet Central Asia, Himalayan India and Pakistan. It is grown extensively in the temperate region. The major apple growing countries are Australia, Argentina, Brazil, China, Canada, Denmark, Egypt, France, Gemany, USA, India, etc. In India states of Jammu and Kashmir, Himachal Pradesh and mountanous region of Uttar Pradesh are the major apple producers.

Cultivars/Varieties: The apple varieties are divided into three groups based on their maturing periods. The early season varieties grown in the states of Himachal Pradesh, Jammu & Kashmir and Uttranchal are: Tydeman’s Early(P), Irish Peach, Early Shanburry(P), Michael Molies, Benoni Fenny, Benoni Delicious, Schlomit Starkrimson, and Chaubattia Princess. The Mid season varieties are: American Mother, Red Delicious, Richared Razakwar, Starking Delicious, Vance Delicious, Jonathan(P), McIntosh(P), Top Red Lord Lam, Cox’s Orange Pippin(P), Cortland bourne(P), Red Chief, Red Gold(P), Golden Delicious(P), Oregon Spur, Queen,s Apple, Redspur, Rome Beauty, Scarlet Siberian. The late season varieties are: Golden Delicious(P), King’s Pippin, Rymer, Yellow Newton(P), American Apirouge, Buckingham(P), Winter Banana, Kerry Pippin, Granny Smith(P), Sunhari Chamure, Golden Delicious(P), Red Delicious, Ambri Baldwin, and Yellow Newton(P).

The apricot, Prunus armeniaca, L. is a species of Prunus, classified with the plum in the subgenus Prunus. Apricot is believed to have been originated in North-east China and later spread to several parts of the world. The important apricot producing countries are China, Turkey, Italy, Spain, Greece, USA, Morocco, France, Romania, Iraq, Bulgaria, Afghanistan, Pakistan, Iran, India and Australia. In India it is cultivated in Jammu & Kashmir, Himachal Pradesh, Uttarakhand and North East Himalayan region.

Cultivars/Varieties: Hemskerk, Moor park, Kaisha, New Large Early, New Castle, Royal, Raksona, Shiply Early, St. Ambroise, Wenatchee, Chaubattia Alankar, Chaubattia Madhu, Chaubattia Kesri.

Uses

It is used in many ways, such as, in the preparation of jam, nectar, beverages, puree, leather, etc. The karnel is a source of cooking oil. Leaves are used as fodder. Oil cake is used as cattle feed. Dried apricot is an important commercial product.

The avocado (Persea americana Mill) belonging to the family Lauraceae, may have originated in southern Mexico but was cultivated from the Rio Grande to central Peru long before the arrival of Europeans. It was then distributed into the West Indies and all other parts of the tropical and subtropical world. It reached India probably in 1892. Now it is grown in Tamil Nadu, Karnataka, and Kerala in India, to a limited extent.

Cultivars/Varieties: Fuerte, Hass, Lula, Pollck, Purple, Green.

Uses

Avocado is low in sugar content and rich in avocado butter, hence can be highly recommended as a high energy food for diabetics. The pulp of the fruit can be preserved by freezing, and can be used as sandwich filling or spread, in ice creams and milk shakes. Though the fruit is high in fat content, it is harmless unlike animal fat. The pulp has butter consistency, and looks very much like cow’s butter and bland in taste with a nutty flavour, without any offensive odour or smell. Its aroma resembles that of tender coconut.

Bael (Aegle marmelos, L.) belongs to the family Rutaceae and is an important indigenous fruit of India known since 2000-820 BC. Bael is considered to be native to India and is grown all over the country. It is also seen in south east Asian countries like Sri Lanka, Pakistan, Bangladesh, Burma, Indonesia and Thailand. It is a hardy plant and can be grown even on marginal soils.

The leaves are trifoliate and aromatic. The leaves of the tree are used in religious offerings. The fruit is usually globose, grey or yellowish with small hard aromatic rind. The pulp is thick mucilaginous, orange yellow in colour with sweet scented aroma. The importance of bael fruit lies in its curative properties. It is used in Ayurveda for its medicinal properties.

There are no recognized or improved varieties of bael with a standard name. It usually goes with the name of locality or region it is grown in. Ayodhya, Etawah, Faizabad Local, Gonda Selection, Kagzi Bael, Kagzi Kalan, Mirzapuri, Darogaji, Ojha, Rampuri Azamati, Khamaria, Deoria Large, Gonda-1 and NB-5 are a few to name.

Uses

Bael fruits cut in half, or the soft types broken open, and the pulp, dressed with palm sugar, eaten for breakfast, as is a common practice in Indonesia. The pulp is often processed as nectar or “squash” (diluted nectar). A popular drink (called “sherbet” in India) is made by beating the seeded pulp together with milk and sugar. A beverage is also made by combining bael fruit pulp with that of tamarind. These drinks are consumed perhaps less as food or refreshment than for their medicinal effects.

Mature but still unripe fruits are made into jam, with the addition of citric acid. The pulp is also converted into marmalade or sirup, likewise for both food and therapeutic use, the marmalade being eaten at breakfast by those convalescing from diarrhea and dysentery. A firm jelly is made from the pulp alone, or, better still, combined with guava to modify the astringent flavor. The pulp is also pickled. The young leaves and shoots are eaten as a vegetable in Thailand and used to season food in Indonesia. They are said to reduce the appetite. An infusion of the flowers is a cooling drink. (Morton, 1987).

Banana (Musa sp), is consumed both as a fruit and vegetable. The sweet desert cultivars are generally called bananas and the starchy cooking types are called plantains. It is an important food crop throughout the tropics. References to the banana is frequently made in the Vedic literature, where its use in religious rituals is quite common. Today, it is a leading tropical fruit in the world market with a high degree of export potentiality. Bananas arrives at the world markets the year round. Though India is the largest producer of banana in the world, Ecuador, Hondurus, Columbia, Costa Rica, and Panama are the leading banana exporter, while USA, Japan, Germany, France and UK are the main importing counties.

Banana is believed to have originated in the warm moist tropical regions of SouthEast Asia. Its cultivation is confined to region between 30° N and 30° S of Equator. Banana is grown in many countries namely India, Philippines, Thailand, Uganda, Zaire, Tanzania, Ivory coast, Burundi, Columbia, Brazil, Ecuador, Venezuela, Bangladesh, the Caribbean Islands, the canary Island, USA(Florida), Egypt, Australia, Sri Lanka.

Banana belongs to the family Musaceae and genus Musa. There are several species of Musa which involves both dipoilds and triploids. Most of the cultivated bananas are triploids. They are further classified based on their genomic status. Bananas and plantains are today grown in every humid tropical region and constitute the 4th largest fruit crop of the world, followed by the grape, citrus fruits and the apple.

Varieties/Cultivars: Though there are more than 25 different kinds of bananas grown in India, Grand Naine, Robusta, Poovan, Ney poovan, Rasthali, Karpuravalli, Tellachakrakeli, Red Banana, Nendran, Monthan, Batheesa, Hill Banana (Veerupakshi & Sirumalai) are the popular varieties grown all over the country with different local names.

Ber (Zizyphus) is egg-shaped fruit of orange or brown colour, with edible acid pulp and hard central stone. The Ber, Indian jujube, Z. mauritiana Lam. (syn. Z. jujuba L.) is adapted to warm climates. It belongs to the family Rhamnaceae. It is often called merely jujube, or Chinese date, which leads to confusion with the hardier species. Other English names are Indian Plum, Indian cherry and Malay jujube. In India, there are 90 or more cultivars differing in the habit of the tree, leaf shape, fruit form, size, color, flavor, keeping quality, and fruiting season (Morton, 1987). Ber (Zizyphus pss.) is one of the hardiest fruit trees cultivated in India. It is an ideal fruit crop for arid and semi-arid regions and even for waste lands. Ber has been recognized as a useful edible fruit since mythology of Ram and Shabari in India and depicted in Ramayana. Researchers mention both Z. mauritiana and Z. jujuba and even the wild Z. nummularia.

Cultivars: Umran, Banarasi Karka, Seo, Gola.

Uses

The Jujube is classed with the raisin, date, and fig as a pectoral fruit, being nutritive and demulcent. It is eaten both fresh and dried. Bark is used for tanning. Leaves are laxative and used in throat trouble. Leaves are also used as a good fooder particularly in arid zones. The tree serves as a host for lac insects. Wood is used for making agricultural implements and tool handles. The preserved products made of ber fruit are murabba., candy, diced ber, dehydrated ber, ber pulp, ber jam etc.

The carambola, Averrhoa carambola L., is believed to have originated in Malaysia and the Molucca but it has been cultivated in southeast Asia for many centuries. It belongs to the family Oxalidaceae. The carambola, Averrhoa carambola L., is usually called balimbing, belimbing, or belimbing manis (“sweet belimbing”), to distinguish it from the bilimbi or belimbing asam, A. bilimbi L. In Ceylon and India, the carambola has the alternate names of kamaranga, kamruk, or other variants of the native kamrakh.

Cultivars/Varieties: Sweet and sour forms are recognized a cultivar in India. In countries like Australia, Japan, Taiwan and, USA named cultivars are grown.

Uses

Fruits are mainly used for dessert purpose. Slightly unripe fruits are used for jelly and pickle. Unripe fruit is also used for dying as it contains potassium oxalate. It is a popular substitute for tamarind in cooking. The acid types of carambola have been used to clean and polish metal, especially brass, as they dissolve tarnish and rust. The juice will also bleach rust stains from white cloth. Unripe fruits are used in place of a conventional mordant in dyeing. Carambola wood is white, becoming reddish with age; close-grained, medium-hard. It has been utilized for construction and furniture.

Cherimoya is considered as the most esteemed of the fruits of the genus Annona (family Annonaceae). A. cherimola Mill., because of its limited distribution, has acquired few colloquial names, and most are merely local variations in spelling, such as chirimoya, cherimolia, chirimolla, cherimolier, cherimoyer. The cherimoya is believed to be indigenous to the interandean valleys of Ecuador, Colombia and Bolivia. It is cultivated in Australia, Hawai, Brazil, Mexico, India, Sri Lanka, Jamaica, Spain, Costa Rica, Africa and Argentina. In India it is found growing in states of Maharashtra, Tamil Nadu, (Nilgiris and Palani hills), Karnataka (the Nandi hills) and Andhra Pradesh (Telangana region).

It bears fruits with skin which is thin or thick, may be smooth with fingerprint-like markings or covered with conical or rounded protuberances. The sweet, juicy, white flesh is melting, subacid and very fragrant. The fruit is of a primitive form with spirally arranged carpels, resembling a raspberry. Each segment of flesh surrounds a single hard black bean-like seed.

Cultivars: Fingerprinted, Smooth, Tuberculate, Mammilate and Umbonate are the cultivars having different shapes, texture and morphology.

Uses

The flesh of the ripe cherimoya is most commonly eaten out of-hand or scooped with a spoon from the cut open fruit. It really needs no embellishment but some people in Mexico like to add a few drops of lime juice. Occasionally it is added to fruit salads or used for making sherbet or ice cream. Colombians strain out the juice, add a slice of lemon and dilute with ice-water to make a refreshing soft drink. The fruit has been fermented to produce an alcoholic beverage (Morton, 1987). In Jamaica, the dried flowers have been used as flavoring for snuff. All species of Annona can produce seed oil. Essential oils extracted from soursop (pulp) have industrial applications and the oils are also thought to improve the flavour of processed fruit products.

Citrus is one of the most important fruit crops of the world. The most important commercial citrus fruits in India is mandarin oranges followed by sweet oranges, lemons and acid limes. Citrus fruits are used for fresh fruit juices, processing into squashes, marmalades and its essential oils from peel are widely used in flavouring, perfumery and cosmetic industry. The citrus peel is one of the important sources for manufacture of pectin.

It is believed that most of the species under the genus citrus are native to tropical and subtropical regions of South-East Asia, particularly India, China and in the region between these two countries. The north-eastern region of India is considered as one of the natural homes for few species of citrus. The other major citrus producing countries of the world are Brazil, USA, India, China,Mexico, Spain, Egypt, Italy, Indonesia and Trukey.

Sweet Orange (Cirus sinensis Osbeck) or Mosambi

Sweet orange is one of the most widely favored citrus fruit of of the world. Its scientific name is Citurs sinensis Osbeck. The sweet oranges are generally round to oval in shape; tight skinned with solid central core. The skin is yellow to orange in colour, smooth and pulp is yellow to orange or reddish. The segments are tightly attached to one another. The commercially important varieties are Malta (Blood Red), Mosambi and Satgudi. Other exotic varieties like Valencia, Washington Navel of USA and Shamouti of Isreal.

Genus Annona belonging to the family Annonaceae, contains more than seventy species of woody shrubs and trees, all of which produce aggregate fleshy fruits. Of these only a few produce edible fruits of commercial importance. Of all, Annona squamosa L. is probably the most popular fruit. It is also known as ‘Sitaphal’ or ‘Shariffa’. These can withstand drought better than many other fruit trees. Other species of the genus Annona providing edible fruits are A. reticulata L., A. muricata L., and A. cherimola L.

Custard Apple (Annona squamosa Linn.)

The custard apple, Annona squamosa L., also known as sweet-sop or sugar apple, is almost entirely eaten as a dessert fruit. Its pulp may be mixed with milk to form milk shake or made into ice-cream. The pulp has a pleasant texture and flavour. Several products like -squash, nectar, pulp butter, syrup, jam can be made from the pulp.

Custard apple is native to tropical America (Mexico). It is cultivated in Australia, Brazil, Chile, Egypt, India, Israel, Myanmar, Mexico, Philippines, Spain, Sri Lanka, South Africa, West Indies, USA and Cuba. In India it is popular in Andhra Pradesh, Madhya Pradesh, Tamil Nadu, Karnataka, Maharashtra, Uttar Pradesh, Orissa, Asssam, Bihar and West Bengal.

Cultivars: The cultivars vary in their shape, size, colour and eating quality. Some of the cultivars are Balanagar, Sangareddy Local, Chittorgarh, Barbados, British Guinea, Mammoth, Red Sitaphal, Yellow Sitaphal, Custard Apple Selection-1, Custard Apple Selection -2. Arka Sahan is a hybrid developed by ICAR-IIHR, Bangalore.

Date-palm (Phoenix dactylifera L.). belongs to family Palmae and is the most common tree of desert and dry areas. Date palm is one of the oldest trees known to man kind. Date-palm is believed to have originated in the countries around Persian Gulf. It is extensively grown in Iraq, Iran, UAE, Saudi Arabia, Algeria, Egypt, Libya, Yemen, Mauritiana, Morrocco, Tunisia, Baharin, Sudan, USA, Spain, Australia, Pakistan, South Africa, Somalia, Oman and some parts of the South America. Date is a staple food of the people of the Western Iraq and North Africa. In India, it has been believed to be introduced by soldiers of Alexander the Great in 4^th century B.C. In India it is commercially cultivated in Rajasthan, Punjab, Hariyana and Gujarat.

Cultivars: Deglet Noor, Halawy, Khadhrawi, Hayani, Majhul, Zahidi, Khalaeh.

Uses

Date palms produce many products that are useful to human beings. The primary product is the date fruit, which can be eaten fresh, dried, or in various processed forms. In North Africa and the Middle East, some dates are harvested and consumed during the Khalal stage, when the fruit are still very astringent with a high tannin content (Dowson and Aten, 1962 ; Glasner et al., 2002; Kader,1992). Dates can be used in cereal, pudding, bread, pressed cakes, cookies, candy bars, ice cream, and date shakes (a California specialty). Date fruit also can be made into juice, vinegar, wine, beer, sugar, syrup, honey, chutney, pickle, paste, dip, and food flavoring (Barreveld, 1993; Glasner et al., 2002).

It is said that there are as many uses of dates as there are days in a year. The trunk and wood of date palms can be used as timber, wood, or fuel. Fiber from the trunk and leaves can be made into bags, baskets, camel saddles, cords, crates, fans, food covers, furniture, mats, paper, ropes, trays, and twine. Dried bundles of leaves (‘‘Barusti’’) can be made into shades, roofs, separating walls, and enclosures. Ribs of the leaves can be used to build boats (small fishing boats called ‘‘Shasha’’) or fishing traps. The base of the leaves and fruit stalks can be used for fuel. The pith of the palms can be made into date palm flour. Terminal buds (palm heart) can be eaten as a salad or as a cooked vegetable. Date seeds can be used as feed for livestock or strung as beads for decoration. Oil from date seeds can be manufactured into soap (Chao and Krueger, 2007). Dates are considered a balanced and healthy diet and have several medicinal uses. Leaves are source of fibre used for making ropes baskets and cordage. Walking sticks are made from leafstalk.