eChapters

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.

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.

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).

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

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.

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

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.    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

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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 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.

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.

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.

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.

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.

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.

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.

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. 

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.

Cauliflower follows cabbage in importance with regard to area and production in the world. However in India Cauliflower is more widely grown than cabbage. This crop grows at a latitude 11°N to 60°N with average temperature ranging from 5- 8°C to 25-28°C. It can stand to the temperature as low as -10°C and as high as 40°C for a few days. Italy and India are the major countries growing CF on large scale. Important cauliflower growing states in India are UP, Karnataka, West Bengal, Punjab and Bihar. It is commonly grown in Northern Himalayas and Niligiri hills in south.

Origin and Distribution: Cauliflower is thought to have been domesticated in the Mediterranean region since, the greater range of variability in the wild types of B.oleracea is found there (Nieuwhof, 1969). Wild Cole warts are still found in wild state in sea cost of England and Denmark and in the North West France and various localities from Greece to Great Britain. The Cole crops, including cauliflower and cabbage have descended from a common Kale like ancestor, the wild cabbage (B.olearcea var. sylvestris L.) which is still found in western and southern Europe and North Africa (i.e, sea coasts of England and Denmark and in North West France and various localities from Greece to Great Britain). Cyprus and area around Mediterranean courts are considered to be the primary centers of origin for Cauliflower. It is also reported that cauliflower is originated from a related species. B.cretica. As per Bosewell (1949), it originated in the islands of Cyprus from where it moved to other areas like Syria, Turkey, Egypt, Italy, Spain and North Western Europe. Cornish types originated in England fallowed by temperate types originated in Germany and Netherlands in 18th century. The present Indian tropical cauliflowers developed as a result of intercrossing between European and Cornish type. In India tropical types with resistance to high temp and high rainfall conditions have been developed. Tropical types are grown in Indian plains from May to September, followed by temperate types known as snowball cauliflower.

Cabbage

Cabbage is an important crop in USA, Northern European countries, Russia, Japan & Australia and its breeding occurs here, but Holland and Japan are the major breeding countries. It is also being cultivated in India and crop improvement work is taken up in India also.

Origin and General Botany: Historical evidence indicates that modern hard head cabbage cultivars descended from wild non headed Brassica originated in the Eastern Mediterranean and in Asia Minor. The Celts and Late Romans are responsible for spread cabbage throughout Europe. Latin name Brassica derived from Celtic word “bresic” meaning cabbage. Over a period hard headed evolved in Northern Europe and loose headed and heat resistant types evolved in South Europe. Cabbage was first introduced to America in 1541 by French explorer Jacques Cartier (planted seeds in Canada) and earlier colonist introduced the crop in to India also. Round headed types-are evolved earlier than flat (evolved in 17th or 18th century).  Broccoli, Cauliflower, Brussels Sprout, Collards, Kale, and Kohlrabi are all readily intercrossed members of this species.

Onion

Onion is very popular vegetable crop grown worldwide. Consumption is in the form of fresh, frozen, and dehydrated bulbs and green bunching onion. Origin of Allium cepa is still somewhat mystery. Vavilov (1951) suggested that the onion originated in the area of Pakistan. Others have suggested Pakistan, Iran & the mountain areas to the north (Jone& Mann, 1963). One fact is certain that the onion has been around in its present edible form for thousands of years. Onion recorded in tombs as early as 3200 B.C. It was mentioned as a food in the bible and in the Koran with reference thought to be around 1500 B.C. In addition to being a food considered by people, plant is having certain healing power. Some early drawing indicates that onions were used in spiritual offerings.

Dolichos bean is known as Lablab bean, hyacinth bean or sem. Grown as field crop in MP, Maharashtra, AP and TN. Genus Dolichus is renamed as Lablab (Syn. D. lablab, D. purpureus, Lablab niger, L. bvulgaris) and Lablab purpureus name is widely accepted. Dolichos lablab L. (synonyms Lablab purpureus (L.) Sweet.) is leguminous pod vegetable grown in tropics and few temperate countries. Lablab niger var. lablab is synonym to Dolichos lablab var. typicus where long axis of seed is parallel to suture and is vegetable type. Lablab niger var. lignosus synonym to Dolichos lablab var. lignosus where long axis of seed is perpendicular to suture and is pulse type.

Southern pea / black eyed pea are the other names associate with cowpea. It is grown for vegetable and also as pulse crop and varieties are specific for use.

Classification of Cowpea
1.    Vigna unguiculata (L.) Walp. Cv. Sesquipedalis: yard long bean or asparagus bean: Possess long pods and used as vegetable. 
2.    Vigna unguiculata (L.) Walp. Cv. Cylindrica: dual purpose, i.e. vegetable and pulse 
3.    Vigna unguiculata (L.) Walp cv. Radiata: Pulse type.
 
More emphasis is given for pulse types for crop improvement. Less attention is given to vegetable types. Pole and bush types are available in vegetable type. Cowpea improvement is from vine to bushy habit with low fiber content and low glucosides and increased protein content.
Origin and Distribution: Cowpea is in cultivation from ancient times in the tropics of old world. Country of origin is uncertain. In India, it has been known from the vedic times. Vavilov (1939) considered India as the primary centre of origin. But it is now generally agreed that Africa is centre of origin since wild forms are found in Africa and in Asia wild forms are absent (Smartt, 1990). Faris (1965) concluded that, cowpea arose from domestication of wild form Vigna unguiculata ssp dekindtiana in West Africa. But domestication is actually happened in Ethiopia and dissemination was West wards Africa, East ward across the Indian Ocean. It has spread from Africa to Asia and Europe through Egypt. Introduced to West Indies in 16th century by Spaniards and was taken to USA around 1700. Now cowpea is widely distributed throughout the tropics and subtropics.

Among beans, the most popular bean is French bean and it has wider distribution and larger gene pool. Various names are associated with cultivars viz., Snap bean, salad bean and green bean and all these names associated are with beans of vegetable types. The names haricot bean, dry bean and navy bean are applicable to pulse types. String bean, dwarf bean and pole bean applicable to growth forms. It is known as Rajmah in Hindi, Tingalawari in Kannada and Fras bean in Punjabi. Cultivars preferred for Canning, frozen and freeze-dried are having round pods. Fresh market cultivars are flat or oval shaped. Yellow pod cultivars are also grown. Generally fresh market cultivar yields higher in temperate region than in tropical region. Beans are said to be antidiabetic and good for bladder burns, cardiac, carminative, diuretic.

Origin and Distribution: Phaseolus vulgaris was domesticated in Central America about 7000 years ago and it is also thought to be domesticated in Brazil and Northern Islands and was introduced to Europe in 16th century. Vavilov (1951) reported that Phaseolus vulgaris originated in South Mexico and Central American centre of origin. The first cultivar has been selected in Peru. From Peru it spread to Europe and to Asia. Wild species P. aboriginus in North West Argentina is considered as the wild progenitor of French bean. Based on growth habit, crop can be classified into pole type, semi pole type and bush type. Former varieties are more string types. American origin of P. vulgaris is questioned by De Candolle (1584). Southern part of Mexico and Central America are considered to be primary centre of origin. While secondary centre lies in Peru-Bolivian-Ecuador of South American continent. In Europe, French bean spread rapidly in 16th and 17th centuries and reached England by 1594. From Europe, it was introduced to India during 17th century (Simmonds, 1976).

Keys to Genera
Flowers zygomorphic, stamens definite, corolla papillonacious, petals imbricate: 1I, 1O, 3 IO
Group I:    Herbs or shrubs, leaves imparipinnate, leaf lets entire, pods usually dehiscent, or if indehiscent usually small, a few seeded. Cyamopsis
Group II:    Herbs low or climbing, leaves paripinnate, leaflets ending in a tendril or bristle, style bearded, pods dehiscent.
Sub group 1: Staminal tube oblique at mouth, pod compressed. Vicia
Sub group 2: Staminal tube truncate (cutting off) at mouth, pods torpid.  Pisum
Group III:     Climbing or prostrate and rarely erect
Sub group 1: style bearded, stamen diadelphous
Sub-sub group: stigma terminal: Dolichos
Sub-sub group: Stigma oblique: Keel spiral : Phaseolus
Keel not spiral: Vigna
Sub group 2: Style not bearded, stamen monodelphous: Canavalia
Group IV:    Trees or shrubs, some times climbing, pods indehiscent: Psophocarpus

Garden Pea
It is cool season crop cultivated throughout the world. It is extensively grown in temperate zone and is restricted to cooler altitudes in tropics and winter season in sub tropics. It is rich source of proteins (25.6%), amino acids and sugars. It goes well with other vegetables in vegetable dish.

Squashes and Pumpkin (Cucurbita, spp, 2n = 2x = 40) are the words quite often used interchangeably. However, the term squash is more commonly used for C. pepo which is consumed as an immature fruit. The term pumpkin is normally applied to the edible fruit of any species of Cucurbita utilized when ripe as a table vegetable or in pies.
 
Origin:  The genus Cucurbita is native to America.  The center of diversity is the tropics near the Mexico- Gauatamla border. The archaeology evidences indicate that these were widely cultivated in South Western United States, Mexico, and northern South America in Pre-Colombian times i.e. prior to 1492 A.D.

C. pepo : Summer squash : Some varieties belong to winter squash, pumpkin and marrows. It has bushy habit, peduncle hard, sharply angular, grooved, leaves broad, triangular in outline, usually with deep lobes little or no expansion of peduncle at fruit attachment. In North America it is commonly found.

C. mixta : Squash, cymlins, cushaws: It is used as summer and winter squash, leaves shallowly lobed, hard corky peduncle. This is also commonly found in North America.

Bottle gourd (Lageneria siceraria) 2n=2x=22 is also known as white flowered gourd. Most important vegetable of ancient China.
 
Origin : According to De Candolle (1882) Bottle gourd has been found in wild form in South Africa and India. However, Cutler and Whitaker (1962) are of the view that probably it is indigenous to Tropical Africa on the basis of variability in seeds and fruits. This species appear to have been domesticated independently in Asia, Africa and the New world (Heiser, 1973).
 
Botany: It is monoecious, annual vine with soft pubescence. Leaves are cordate ovate to reniform-ovate, Flowers are white, solitary, open at night and has hairy ovary. Fruit shape is cylindrical, oval egg shaped, club shaped, round and other shapes also appeared.

Genetics of Important Traits

Bitterness: Single dominant gene (Path and Singh, 1950)

Fruit colour: Monogenically controlled (Kalloo, 1993)

Two major genes are involved for fruit shape (Path and Singh, 1950). Single gene for fruit colour involved (patchy v/s white) and reported by Path and Singh (1950). Monogenic recessive inheritance for andromonoecious sex form is reported by Singh et al. (1996). Hermaphrodite sex form is characterized by long corolla (3.5-4.5cm instead of 2.5-3.5cm in normal). In hermaphrodite condition fruits bears prominent blossom scar.  Long fruit conditioned by AA genotype and Round fruit is due to aa genotype where Partial dominance is reported (Kushwaha, 1996).

It is rich in iron and Vit –C and native of tropical Asia particularly eastern India and Southern China (Sheshadri 1986 Mini Raja et al., 1993).
 
Botany: Monoecious annual, staminate flowers small, yellow and borne on slender pedicel. Pistillate flowers solitary have small pedicel, flowers are yellow, leaves segmented pentamerous. Filaments 3, two are bilocular and one is unilocular. There are three short styles ended with three bilobed or divided stigmas.

Chromosome 2n=22: 6-centromere in middle, 3-submedian, 2-subterminal  (Vargheuse, 1973) 

Momordica dioica: 2n=28

Momordica cochincniensis: Sweet gourd of Assam

Germplasm

KAU-Vellanikara, IIHR-Bangalore, NDUAT-Faizabad, CSAUAT-VRS, Kalyanpur, BPUA&T-Pantnagar and IARI- New Delhi are the major sources of bitter gourd germplasm.

Ridge gourd or Ribbed gourd (Luffa acutangula Rox b. L) and Sponge gourd or Smooth gourd (Luffa cylindrica) have diploid chromosome number  2n=2x=26. Luffa has old world origin in Subtropical Asian region including India (Kalloo, 1993). These two species are inter-crossable. F1 plants generally, intermediate between the parents and showed various irregularities like, univalants, rings and chains of 4 chromosomes, chromatids bridges and fragments at metaphase and thus the species are not easily crossable and the F1 plants appear to be of not much practical value. The genus is monoecious annual vine, tendrils are branched, flowers are yellow, anthers are free and pistil has three placentas with many ovules and stigma are three and bilobate. Fruits oblong or cylindrical and rind becomes dry on maturity.

Water melon is tender to frost and most of cultivars require relatively long growing season. Plant growth and fruit development are fallowed by higher temperature and abundant sunlight. Atmospheric humidity greatly regulates fruit and foliage diseases.

Taxonomy and Origin: Ealier it was classified as Citrullus Vulgaris Schrod. But in 1963 Thieret called attention to the correct name, C. lanatus (Thumb) Mansf. Africa is centre of origin of the genus. In 1857 David Living Stone, the famous missionary explorer found both bitter and sweet melons grown together in Africa and native people used them as source of water. Cultivation is prehistoric as there are pictures made in ancient Egypt. Early cultivation occurred in Mediterranean area and as far as India also and It was brought to USA by European colonist as early as 1629.

Melons (Cucumis melo) are annuals with climbing, creeping or trailing vines of length up to three meters. The desert types quench thirst and add to the nutrient content of main diet. The non-desert types are used as vegetables. Muskmelon (Cucumis melo., 2n=2x=24) encompasses the netted, salmon -flesh cantaloupe, the smooth – skinned green fleshed ‘Honey Dew’, the wrinkled, white – fleshed, ‘Golden Beauty’ and several other dessert melons in USA.

Origin: Not known with certainty but, 40 or more wild species of Cucumis are found to occur in the tropics and subtropics of Africa. Wild species of Cucumis occur in Africa and it is likely that it originated in African continent. It does not appear to have been known to the ancient Egyptians, not to the Greeks and seemed to have reached Europe towards the decline of Roman Empire. Although melon was introduced into Asia at a comparatively later date there are undoubtedly well developed secondary centers of origin of C. melo in India, China and then Southern USSR. In India Oriental pickling melon (C. melo var conomon) and snap melon (C. melo var momordica) are unique and have considerable variability in Western Ghats of India. They are popular desert and preserving melons cultivated in Warm humid tropical condition of South India. It is also considered that China as primary center of origin and Indo-Burma as secondary center of origin. It has been introduced to Europe and from Europe to the USA by the early travelers. At present muskmelon is being cultivated throughout the world under tropical and subtropical climatic conditions. Polymorphism in leaf, flower, fruit shape and colour (Kirkbride, 1993), allowed the classification of horticulturally important melons into seven groups.

Cucumber

Cucumber (Cucumis sativus) is a warm season vegetable used as salad and for pickling purpose has little or no frost tolerance.  Growth and development favoured  by temperature above 200C.  Cucumber cultivars generally classified as pickling or slicing types. In India often cucumbers (Cucumis sativus) are confused with melons (Cucumis melo ) as morphologically some variants of these species overlap, but they are not cross compatible. Kakri of North India are different from kakri of South India and Maharashtra. In Maharastra and South India cucumbers are referred as kakri but, in North India Kakri means Long melon i.e. Cucumis melo Var. utilissima.

Okra has higher average nutritive value (ANV) of 3.21 which is higher than tomato, egg plant and most of the cucurbits except bitter gourd (Grubban, 1977). Its roasted seeds are substitute for coffee. It is one of the export potential crop where it accounts to 60 per cent of fresh vegetables (excluding potato, onion and garlic) exported from India. Importing countries are Middle East, Western Europe and USA.

Origin and Distribution : It belongs to the genus Abelmoschus established by Medikus, 1787, however de Candolle (1824), treated it as section of Hibiscus.   In 1924 Hochreuntiner reinstated the genus Abelmoschus of Medikus stating that calyx, corolla and stamen fused together at the base and fall as one piece after anthesis (deciduous) where as in case of hibiscus these are persistent. Though the genus is of Asiatic origin, the origin of cultigen Abelmoschus  esculentus is variable like India (Master, 1875) Ethiopia {de Candolle (1883) and Vavilov (1957)}, Western Africa (Chevalier, 1940 and Mardorct, 1947) and Tropical Asia (Grubban, 1997) and probably its might have entered India at the end of 19th century. Cultivated okra is of old world origin. It arose as a cultigen in the Abyssinian region (Ethiopia). Wild species are indigenous to Africa.  Three wild species Abelmoschus tuberculatus, A. moschatus and A. ficulneus are native to India. Introduced to Mediterranean region to Europe and Asia. But during Columbian period it was introduced to America.  It still turnout to be polyphyletic (many places) in origin. A. tuberculatus (Indian origin) and an unknown species cross resulted into A. esculentus.

If there is scarcity of food, potato can come to the rescue because of its virtue of high yielding (40-50 t/ha) and is a staple food. It produces more calories per unit area and per unit time than any other major food crops. Potato which is the staple food of Europeans and Americans belong to the highlands of Andean mountainous regions of Peru and Bolivia where it has been cultivated since 6000 years.
 
Origin: Peru, Bolivia. Many wild species occur at Mexico and Central America. Potato was introduced to Europe in 16th century by Spaniards (Salaman, 1966) and in early 17th century to India most probably by Portuguese. There are some suggestions based on linguistic and botanical evidences that potato might have been introduced in India directly from South America across the Pacific Ocean. Earlier potatoes were grown in hilly areas of North and South since British settlers brought the varieties continuously from UK and these were bred for long day temperate conditions of Europe. But in India potatoes are grown in short day-subtropical plains. The seed stocks used to degenerate due to accumulation of viruses and loose their yield potentiality. Seed potatoes were mainly imported from Europe i.e. U.K., Italy and Netherlands and Burma till the beginning of Second World War and the imports gradually reduced.

‘Chili’ (European literature) word derived from ‘Chile’ which means any pepper in Mexico and Central America. Peppers are an important constituent of many foods adding flavor, colour, vit.C and pungency and therefore indispensable to the world food industries. China, Mexico, Japan, Turkey, Indonesia, Pakistan and India are major producers.
 
Origin:  The cultivated chilli is of South American origin. Authorities generally agreed that capsicum originated in the new world (America) tropics and sub tropics. Pepper pods are there from 2000 year old burials in Peru. Decandolle concluded no capsicum was indigenous to the old world (Europe), peppers unknown in Europe until 16th century. Chilli was introduced into Spain by Columbus on his return trip in 1493 and cultivation spread from Mediterranean region to England by 1548 and to central Europe by close of 16th century. Portuguese carried capsicum from Brazil to India prior to 1885 and cultivation was reported in china during late 1700’s.

All capsicum species have 2n = 24. Polyploids with 2n = 36, 48 and  aneuploid 2n = 25 reported

India is the primary centre of origin of brinjal. Decandolle (1904) reported it as native of Asia. In Europe it is not known earlier (before 17th early). According to N.I Vavilov, the egg plant originated in Indo–Burma region and china and spread to South Europe, china and Japan. Vavilov (1951) suggested China a centre of origin of brinjal. Crop is restricted mainly to South and South-East Asia, Southern Europe, China and Japan. Wild brinjal types are available in Southern Coastal area of Africa.

Botany

Solanum melongena’ L. var. esculentum - round or egg shape 
var. serpentinum – long, slender type 
var. depressum – dwarf brinjal plant 
It is often cross pollinated crop due to heteromorphic flower structure (heterostyle)

Tomato is relatively recent addition to the world’s vegetable crops. Now became one of the most important vegetable crops and is popular & widely consumed. It is being grown extensively in USA, China, India, France, Israel and Netherland.
 
It is used in fresh and processed form. Among the vegetables maximum attempts have been made to improve this crop because of its short duration, easy cultivation and large number of seeds per fruit and this has made it an ideal crop for many research works. An exclusive Tomato Genetics Co-operative located in University of California, USA, published genetic information on the crop and maintains a large number of     collections which have already been thoroughly catalogued.
 
Origin and Distribution: Native of Peru in South America and spread to North America by migrating birds. Largest number of wild tomato forms is present in Mexico. Spanish Priests introduced it to Europe in around 1550. In Europe it is known as Poma amoris = Amorous apple (Love apple). Wild relatives found in narrow elongated mountainous regions of Andes in Peru, Ecuador and Bolivia and Galapagos islands. Domestication and cultivation of tomato appears to have first occurred outside its centre or origin. Domestication of tomato was first done by Mexican people i.e. Red Indians, which is considered as secondary center of origin. Now cultivated tomato is common in Peru but recently added to their diet.

1. Botanical Name : Zizyphus rugosa Lamk

2. Family : Rhamnaceae.

3. Common Name : Wild Jujube, wrinkled jujube

4. Name in Indian languages

Churna, Suran (Hindi), Toran, Turan (Marathi), Totari (Tamil), Thodali, Tutari (Malayalam), Gottichettu (Telugu), Belahadu, Mulluhannu (Kannada), Kotte pan (Kodwa).

5. Description

Zizyphus rugosa is a large armed, spiny, evergreen tree growing around 5 - 9 metres tall with large elliptic usually subcordate leaves, paniculate flowers and wood is reddish, moderately. This plant is found chiefly in deciduous and semi-evergreen forest, hills and mountains below 1200 m altitude. The leaves are simple, and are broadly elliptic and short tips. Fruits are globose or pyriform, white when ripe. Whole fruit expect the seed is consumed at ripe stage. It is found in degraded forest areas of entire of Western Ghats. The plant is harvested from the wild for local use as a food and a medicine.

1. Botanical Name : Zizyphus nummularia Burm. f.

2. Family : Rhamnaceae

3. Common Name : Jhar Ber

4. Name in Indian languages

Jhar ber, Bordi, Jharberi (Hindi), Bhubadari (Bengali), Mulluhannu (Kannada), Junglebor (Marathi), Bhu-kartaka (Sanskrit), Narielandai (Tamil), Nelaregu, (Telugu), Poast jharberi (Urdu).

5. Description

Jhar ber (Ziziphus nummularia) is a most commonly occurring branched thorny shrub species in the Indian desert with a height of 1-2 m. It occupies almost all the habitats including crop lands and grazing lands. It is found growing naturally on farm lands and spreads through root suckers and also by seeds. It forms an integral part of rain fed farming system in arid zones of Rajasthan. Underground suckers of jhar ber remain dormant during summer season but they sprout with monsoon rain and complete the life cycle including vegetative growth, flowering and fruiting by November-December. The bushes are headed back at ground level after the kharif cropping season is over.