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India is one of the largest producer of the pomegranate. Apart from India, Spain, Iran, Egypt, Peru, Israel, Pakistan, Afganisthan, Turkey and America are the countries where the crop is cultivated. World production of Pomegranate is around 10 Lakh tones out of which India’s share is 40-45 percent .At present Spain is the maximum producer and exporter of pomegranate due to high quality and low transport cost capturing most of the European market. The total demand for pomegranate in the world is around 1.5 Lakh tones, which is increasing day by day. Spain contributes 75,000 to 80,000 tones (75%)of the total demand followed by Iran 25,000 tones and India 10000 tones (5%). Thus to increase the export there is only one way to improve the quality.

Lesser yam, Lesser Asiaticyam (Dioscorea esculenta) is among the most ancient species of the genus and its centre of origin is stated by various authorities as India, Vietnam or Papua New Guinea and the Philippines. It is domesticated as a staple food in Southern China from 2nd and 3rd centuries. Today, it is widely distributed throughout the tropics, but is little used except in South East Asia, where it is grown to such an extent that it ranks third in production and utilization of yams after D. rotundata,D. cayenensis and D. alata. Wild types of D. esculenta also exist in Malaysia, New Guinea and Philippines.  The wild types have more leaves, large roots, longer stolons, more fibrous tuber flesh and more thorny roots and shoots.

Classification
The wild types of D. esculenta (Family: Dioscoreaceae) exist in Malaysia, New guinea and Philippines. Wild types have more vigorous foliage, larger leaves, longer stolons, more fibrous tuber flesh and more thorny roots and shoots.  On the basis of thorniness, the cultivated types are distinguished into two botanical varieties.

In literal sense a species is called underutilized whose potential has not been properly realized. These underutilized crops (referred to also by other terms such as minor, orphan, neglected, underutilized, underexploited, underdeveloped, lost, new, novel, promising, alternative, local, traditional, niche crops) have been included in world-wide plans of action after having successfully raised the interest of decision makers. Wealth of plant genetic diversity currently available holds vast potential. We use only small number of crop plants for our basic requirements. Many thousands of wild plants have great economic and cultural importance and tremendous market potential for vast numbers of people throughout the world. But the majority are still unknown to science. Plant genetic resources have gained global attention in  recent past by agricultural and environmental institutions. Conservation and use of genetic resources attracted  considerable attention. Value of biological diversity in economic terms is very important for human society.

Aonla or Indian Gooseberry (Emhlica officinalis Gaertn. syn. Phyllanthus embfica L.). belonging to family Euphorbiaceae. is an indigenous fruittree to Indian sub continent. It is one of the most important commercial crops suitable for marginal soils and various kinds of waste lands particularly salt affected lands. A lot of genetic variability is available in India with respect to growth and fruit quality characteristics of aonla. Almost all the budded varieties of aonla were selected from naturally occurring superior chance seedlings having in view their earliness, lateness, hardiness to adverse conditions, yield and superior fruit quality.

1-or successful aonla orchards, it is utmost necessary to have basic knowledge of various cultivars suitable for a particular set of environmental and soil conditions.

Genetic resources for food and agriculture are the biological basis of world food and nutrition security and they directly support the livelihood of people. Horticultural genetic resources are a few of biological assets available to resource-poor farmers to ensure sustainable production to improve livelihood options. Genetic diversity gives resource-poor farmers a low cost option to manage the shocks and vulnerability of production systems by its ability to adopt to changing environments. It is the foundation upon which plant breeding depends for the creation of new varieties and is, therefore, of critical public value for global food security. The rapid loss of genetic diversity (genetic erosion) is a worldwide concern and is particularly severe among crop landraces. Farmer’s varieties or landraces may contain co-adapted gene complexes that have evolved over decades and are the most valued genetic resources as they provide options for a range of climatic and edaphic stresses. Therefore, agricultural biodiversity has a critical public value for global food security (FAO, 1978).

Carambola (Averrhoa carambola) is a fruit of warm tropical and sub- tropical areas of the world. The fruit is oblong with three to six longitudinal ribs, resulting in a star shaped cross section when cut. Usually they have five ribs which give rise to common name of ‘five corners’ or ‘star fruit’. The tree is medium-sized, attractive and evergreen growing to about 10m. The fruit has emerged as an interesting addition to the table fruit, not only as fresh fruit, but also for its juice, decorative uses and sherbet qualities.

Promotion of perennial crops is a good alternative for food security since they offer more consistant, year-round production without any break. Agathi and Chekkurmanis are the two nutritive perennial greens that can be easily grown in hot and humid tropical climate.

The Begonia family has a tropical and subtropical distribution in America, Asia and Africa. With approximately 100 species and 10,000 cultivated hybrids, they are very important as ornamental plants.A few reports describe Begonia as edible; the highest number of these species is found in America, some in Asia, and we have only one report of an edible Begonia in Africa.

The Begonia family has a tropical and subtropical distribution in America, Asia and Africa. There are approximately 600 species in America, and the same number in Asia.

Africa, including Madagascar and the Mascarenes, has 158 reported species, one third of which are endemic to Madagascar and associated Isles (Mascarenes, Seychelles and Comoros). Only ones species, B. grandis Dryander, is widely distributed in temperate regions, extending northwards near Beijing (Forrest & Hollingsworth, 2003; Plana, 2003).

Curry leaf (Murraya koenigii Spreng. Syn. Bergera koenigii Koen (N.O Aurantiaceae), Chaleas koenigii Curz ex. Swingle) is a perennial leaf vegetable. It belongs to family Rutaceae. Its genus name ‘Murraya’commemorates John Adam Murray, Professor of Botany at Gottingen and editor of many of Linnaeus’s works. (Fyson, 1977).

Origin and Distribution

The crop originated in the tarai tract of Uttar Pradesh (India), in the foothills of the Himalayas. Wild forms with less pungent leaves are seen along the plains and hills of Himalayas extending from Kumaon to Sikkim, in Bengal, Assam, Deccan plateau and in Western Ghats. At present, it is cultivated in Myanmar, SriLanka, China, Australia and Pacific Islands. The curry leaf grows throughout India including the Andaman Islands up to an altitude of 1500 m amol (Wealth of India, 1962). Dastur (1970) recorded its wild form in Garhwal hills in Uttaranchal, Sikkim, Bengal, Assam, Central India, Western Ghats, Tamil Nadu and Kerala.  Used as a flavourant and as a leaf vegetable by the early inhabitants, Dravidians, curry leaf was introduced to Southern India when the Dravidians moved southward after the arrival of Aryans from Persia. It is a backyard crop in many of the South Indian homesteads.  The spicy leaves of plants are used extensively for seasoning and flavouring dishes.

Genus : Musa 
Species : paradisiaca L.
Family : Musaceae
Chromosome No. : 2n =22,33,44

The genus Musa has been named after Antonio Musa, who was the official physician to Octovius Augustus the first emperor of Rome, 63-14 BC. Banana (Musa spp.) was perhaps the first among the fruit plants to be cultivated and there is hardly an difference of opinion that banana was one of the first food on which human relied upon. Banana was cultivated in India at very early times which is evident from the fact that Alexander the Great found banana cultivation in Indus river valley. In tropics, banana constitutes an important food crop for man and is a staple food of Buganda (Uganda), Wahaya (Bukoba) and Wachagya (Tanzania).

Genus : Vitis 
Species : vinifera L.
Family : Vitaceae
Chromosome No. : 2n=38, 40

Grapes are considered to be the oldest plants on earth which dates back to 90-95 million years, a time when dinosaurs ruled this planet, hence grape is as old as mankind. Grape is one of the most ancient crops. The Aryans knew grape cultivation as well as to prepare beverages from it. Grape cultivation in India dates back to 11th century BC. Later Muslim invaders from Iran and Afghanistan in the 12th century also introduced grapes to India, further in the 16th century Emperor Akbar the Great introduced and encouraged grape cultivation in various parts of India.

Genus : Actinidia 
Species : deliciosa (Plonch)
Family : Actinidiaceae
Chromosome No. : 2n = 58, 170, 174

The remarkable fruit of the previous century Kiwifruit is known by various names like China’s miracle fruit, the wonder fruit of New Zealand, Kiwi berry, Chinese gooseberry, Yangtao, Grosella and Mihoutao. In a short period of about two decades the crop has attracted huge inclination towards its cultivation and has become an established fruit crop of different world markets, which is unparallel in history of commercial fruit culture. In China the fruit has been growing over centuries in its wild form. The name Mihoutao was used for this crop by the Tang dynasty which indicated peach of the Macaque monkey indicating both the presence of fruit in wild stands and the love of the local monkey for this fruit.

Genus   : Ribes 
Species : nigrum L. americana Mill.
                bracteosum Dougl. niveum 
                Lindl. divaricatum Dougl.
Family : Saxifragaceae / Grossulariaceae
Chromosome No. : 2n = 16

The genus Ribes belongs to the family Saxifragaceae mainly comprises of woody shrubs distinctly marked with spines and prickles and those which have attractive handsome foliage, flowers and fruits.  The genus name Ribes is likely to be derived from ribas, the Arabic name for Rheum Ribes. Some are of the view that it is the latinized form of riebs,  an old name of currants in Germany.

Genus : Prunus 
Species : domestica institia L. 
                saliciana Lindl.
Family : Rosaceae
Chromosome No. : 2n - 48

Of all the stone fruits, plums are the most varied. They belong to the genus Prunus of the subfamily Prunoideae of the family Rosaceae. All plums have a basic chromosome number of x=8. Plums and related species have been placed in the subgenus Prunophora section Euprunus and Prunocerasus. Six species have been placed in the section Euprunus. Their chromosome number range from diploid to hexploid and are native to the land extending from Europe to China. Thirteen species native to the North American continent are all diploid in nature and have been placed in the sections Prunocerasus. Separation of the plums into the two sections does not appear to have any genetical basis since the species appear to be closely related. Prunus domestica, the European plum, is believed to be the most recent crop species to have arisen within the section Prunophora. Prunus insititia.

Genus   : Prunus
Species : avium cerasus, mahaleb L.
Family : Rosaceae
Chromosome No. : 2n = 16, 24, 32

Records indicate that cherries were in cultivation ever since the beginning of civilization. Cherries exhibit vast genetic variability as is evident from the different species which vary in their ploidy level. Sweet cherries (Prunus avium L) are diploid while sour cherries (P. cerasus, L.) are tetraploid, and commercially more important than the other species. Duke cherry has resulted from hybridization between sour and sweet cherry with intermediate tree and fruit characters. Successful cherry cultivation revolves around climatic factors, prime being the extent and spread of rainfall, variation in day and night temperature, occurrence of frosts, high heat day largely determine the type of cherry that will grow successfully in a particular areas. Hence cherry improvement around the world has so far been localized to few selected areas where different cherries have been successfully grown.

India is predominantly an agriculture based country and 65% of the Indians depend on agriculture. To meet the ever increasing nutritional demands of Indian population, production and productivity of vegetables have to be increased manifold within the limited available land and other resources. Seed is the basic and critical input in which the expected dividends from all other inputs depend and it plays a crucial role for enhancing the stability of productivity. With the ever increasing demands for a mechanized, energy efficient type of agriculture, each seed is expected to produce a vigorous plant, which would develop. uniformly under a wide range of environmental conditions.

Seed enhancement technologies have historical basis dating back hundreds to thousands of years. Seed coating was being practiced by ancient Chinese farmers who coated seeds of rice with mud balls to anchor the seeds in water saturated soil . The Greeks presoaked the cucumber seeds in milk or water to make them germinate quicker. Keeping the seeds in moist cloth or soaking in water prior to sowing was a common practice among the farmers of India from time immemorial.

Demographic explosion, environment pollution, habitat destruction, enlarging ecological footprint, widespread hunger and unsustainable lifestyles, and potential adverse changes in climate all threaten the future of human food, water, health and livelihood security systems. 2010 appears to mark the beginning of uncertain weather patterns and extreme climate behaviour. Events like temperature rise, drought, flood, coastal storms and rise in sea level are likely to present new challenges to the public, professionals and policy makers. Biodiversity has so far served as the feedstock for sustainable food and health security and can play a similar role in the development of climate-resilient farming and livelihood systems. Biodiversity is also the feedstock for the biotechnology industry. Unfortunately, genetic erosion and species extinction are now occurring at an accelerated pace due to habitat destruction, alien species invasion and spread of agricultural systems characterised by genetic homogeneity. Genetic homogeneity increases genetic vulnerability to biotic and abiotic stresses. To generate widespread interest in biodiversity conservation, the UN General Assembly has declared 2010 as the International Year of Biodiversity.

It was in 1968 that the term Green Revolution was coined by Dr. William Gaud of USA to describe advances in agriculture arising from productivity improvement. Even in 1968, I concluded that if farm ecology and economics go wrong, nothing else will go right in agriculture.  I expressed my views in the following words in my lecture at the Indian Science Congress Session held at Varanasi in January 1968:

Exploitive agriculture offers great dangers if carried out with only an immediate profit or production motive. The emerging exploitive farming community in India should become aware of this. Intensive cultivation of land without conservation of soil fertility and soil structure would lead, ultimately, to the springing up of deserts. Irrigation without arrangements for drainage would result in soils getting alkaline or saline. Indiscriminate use of pesticides, fungicides and herbicides could cause adverse changes in biological balance as well as lead to an increase in the incidence of cancer and other diseases, through the toxic residues present in the grains or other edible parts. Unscientific tapping of underground water will lead to the rapid exhaustion of this wonderful capital resource left to us through ages of natural farming.

1. Introduction

Plants are reliable sources for the treatment of diseases in different parts of the world (Eisenberb et al., 1993; Cowan, 1999; Hostettmann et al., 2000) and they have been unique sources of medicines and constituted the most common use of biodiversity (Hamilton, 2004; Hiremath and Taranath, 2010). Their use contributes significantly to primary healthcare delivery (Holetz et al., 2002) as they are regarded as invaluable sources of pharmaceutical products (Olalde, 2005).

Traditional medicine, with medicinal plants as their most important component, are sold in market places or prescribed by traditional healers in their homes (Von Maydell, 1996). As a result of this strong dependence on plants as medicines, many ethnopharmacological studies have been conducted to determine their safety, efficiency and discovery of new active principles from them. Only, 1,100 plants have so far been thoroughly examined for their medicinal practices in the world (Dobson, 1995).

Herbal medicine have been in use since time immemorial and are still the mainstay mainly in the developing countries because of their better cultural acceptability, better compatibility with the human body and lesser side effects (Kamraj, 2000).

1. Introduction

Nothing in the universe is non medicinal everything has its value in its own way. Infectious diseases are an important health hazard all over the world, both in developing and developed countries. Several synthetic antibiotics are employed in the treatment of infectious and communicable diseases. A number of researchers nowadays are working seriously to find out substitutes for antibiotics as they cause side effects on the functioning of different parts of the body organs and systems. Antibiotics are also known to disturb the natural intestinal micro flora, thus depriving the benefits of these microbes to human body. Medicinal plants exhibit antimicrobial activity since they contain innumerable biologically active chemical constituents. The medicinal plant wealth, the strong and time tested traditional medicare systems like ayurveda and the human resource base are the strengths of India. Over the last forty years intensive efforts have been made to discover clinically useful antibacterial/ antifungal drugs (Sashikumar et al., 2003). Over 50% of all modern clinical drugs are of natural product origin (Ates, 2003). Higher plants as sources of medicinal compounds have continued to play a dominant role in the maintenance of human health since ancient times (Farombi, 2003).

1. Introduction

The therapeutic efficacy of many indigenous plants for various diseases has been described by traditional herbal medicine practitioners (Bharat and Parabia, 2010). Natural products are the source of synthetic and traditional herbal medicine. They are still the primary health care system in some parts of the world (Mahmud et al., 2010). In India, local empirical knowledge about medicinal properties of plants is the basis for their uses as a home remedies. It is generally accepted by many Indians and elsewhere in the world that beneficial medicinal effects can be obtained by ingesting plant products. Plants bear the basis of many traditional medicines throughout the world for thousands of years and continue to provide new remedies to mankind (Patel, 2009). The World Health Organization (WHO) also encourages, recommends and promotes the use of traditional and herbal remedies in the National Health Care Program because these medicines are easily available at low cost, comparatively safe and people have faith in such remedies (Wani, 2007). Herbal medicines are promising choice over modern synthetic drugs. Due to the serious obsession with the modern medicinal system, people have started looking at the ancient healing systems like Ayurveda, Siddha and Unani (Shankar and Ved, 2003).

1. Introduction

Medicinal plants are nature’s priceless gift to human. They have been used all over the world for the treatment and prevention of various ailments particularly in developing countries where infectious diseases are endemic and modern health facilities and services are inadequate. Medicinal principles are present in different parts of the plants such as root, stem, bark, heartwood, leaf, flower, fruit or plant exudates (Thenmozhi et al., 2010). Phytochemicals from medicinal plants serve as lead compounds in drug discovery and design (Sofowora, 2006).

Free radicals are chemical species which contain one or more unpaired electrons, due to which they are highly metastable and cause damage to other molecules by extracting electrons from them in order to attain stability (Chakraborthy and Ghorpade, 2010). Hyper-physiological burden of free radicals causes imbalance in homeostatic phenomena between oxidants and antioxidants in the body. This imbalance leads to oxidative stress that is being suggested as the root cause of aging and various diseases like diabetes, cancer, and liver damage (in severe conditions like cirrhosis and hepatitis) (Wagh et al., 2010).

1. INTRODUCTION

The medicinal plants have been used by humans from the pre-historical times. Traditional medicine based on herbal remedies has always played a key role in the health systems of many countries. In India, the native people are exploiting a variety of herbals for effective curing of various ailments. Medicinal plants are widely used by all sections of the population and country is richly endowed with a wide variety of plants of medicinal value, which represents the great national resource (Alok, 1991).

It is estimated that at least 70 percent of population relay on herbal medicines for primary health care in our country (Holley and Williams, 1996). In India, different classical medicinal systems such as Ayurveda, Siddha and Unani are being practiced in the country and in addition to innumerable local folk medicinal traditions exist. More than 8000 species of wild plants are known to be used in India for the treatment of various health problems (Ved et al., 2000). This rich medicinal wealth is mainly distributed in two biodiversity hotspots that are Eastern Himalayas and Western Ghats. Numerous studies have pointed out that many drugs that are used in commerce have come from folk-use and use of plants by indigenous cultures (Anon, 1994). Medicinal plants form a heterogeneous group in growth, habit, distribution, reproduction, phenology and their ecological requirements.

The formulation of ration for various categories of livestock depends upon the nutrient requirements for a particular animal or group of animals and the feeds and fodders available for the purpose. Livestock feeds can be grouped into two major categories – Roughages and concentrates, on the basis of bulkiness and chemical composition and combination of both is essential for a balanced ration.

Roughages are the bulky feeds having crude fiber more than 18% and TDN less than 60% while, Concentrates are feed or feed mixture having crude fiber less than 18% and TDN more than 60%. They are rich in either energy or protein and accordingly are called as energy concentrates (when CP is less than 18%) or protein concentrates (when CP value exceeds 18%). Various energy concentrates are grains and seeds (maize, barley, sorghum etc.), milling byproducts (brans and chunis), roots (tapioca tubers, turnip, potatoes) and molasses.

Chemical warfare involves using the toxic properties of chemical substances to kill, injure or incapacitate an enemy.

Chemical warfare is different from the use of conventional weapons or nuclear weapons because the destructive effects of chemical weapons are not primarily due to any explosive force. The offensive use of living organisms (such as anthrax) is considered to be biological warfare rather than chemical warfare; the use of nonliving toxic products produced by living organisms (e.g., toxins such as botulinum toxin, ricin, or saxitoxin) is considered chemical warfare under the provisions of the Chemical Weapons Convention. Under this Convention, any toxic chemical, regardless of its origin, is considered as a chemical weapon unless it is used for purposes that are not prohibited (an important legal definition, known as the General Purpose Criterion)

Introduction

Aflatoxins are a group of highly subsituted coumarine, of which aflatoxin B1 and G1 are  most  highly hepatotoxic (toxic to liver) to animals. The toxins are produced by some strains of Aspergillus flavus and other species of Aspergillus which develop in many food stuffs, particularly groundnuts. cottonseed, and their cake and flour. Protein concentrates meant for babies as well as adult are now a day  made from groundnut flour and the cakes are used as feed for poultry and livestock. It has been found that even fodgrains such as maize, rice and wheat are attacked by the fungus producing the toxins.

Estimation of Magnesium in Feeds, Fodders and Faeces
(Gravimetric method - AOAC, 1965)
Principle

Evaporation of calcium free filtrate is carried out to drive off ammonium chloride and nitric acid is added to decompose ammonium salts, which is then subsequently driven off by evaporation. NH₄Cl + HNO₃ = HCl + NH₄NO₃ (driven off). Sodium citrate in solution yields citric acid which has got a tremendous effect on aluminium and iron in that the citric acid keeps these materials in solution.

At neutrality, first the normal magnesium phosphate is formed, which is then turned to magnesium ammonium phosphate, which on incineration gives rise to magnesium pyrophosphate (Mg₂P₂O₇).

INTRODUCTION

EGGS : Eggs and egg products constitute an important part of family meals. The economic importance of the egg to agriculture and industry, its multiple uses in the preparation of many food products, and its excellent nutritive value have stimulated scientific scrutiny into the nature of the egg.

STRUCTURE : The chief parts of the egg are the yolk, the albumin (the white), and the shell and the shell membranes. The yolk is more complex structurally than may be thought at first glance. At the very center is a light coloured structure called the white yolk. The vitelline membrane serves as the enclosure or sac for the yolk. The strength of this membrane is important when yolks and whites needs to be separated in cookery. Two important rather twisted membraneous structures extend from opposite sides of the yolk into the white.

(I)  Breeds

Basically swine is a clean animal and in our country, mainly, poor people  are rearing them with the least available infrastructure and poor quality feed, usually garbage, and that is why swine  are forced to take garbage as a feed (Fig. 23). With good food and shelter, they can give birth twice a year with better productivity. Even 8000- 9000 years back swine stood at 3^rd position for being reared by humans after cattle and sheep. Swine comes under phylum Chordata as they have vertebral column and their class is mammalia. They come under Artiodactyla for being ungulate animals. Swine comes in Swede order and their species is swiss. They have 3 subspecies. The domesticated subspecies comes under Swede domesticus and wild pigs comes under Swede vitatus and Swede scrofa. In India there are 4 breeds of pigs. Wild, desi, exotic and crossbred.

Rivolta (1873) first described the chain forming cocci in pus collected from the equine infection. Later Rosenbach established the genus ‘Streptococcus’. Nocard and Mollereau (1887) first observed the relationship between the bovine mastitis and Streptococcus agalactiae.

Properties of genus

1. Morphology : Streptococci are gram positive cocci, capsulated, non-sporing and non-motile. Each coccus cell is 1µm in diameter.  They are arranged in a pair or chain of cells as the cell division occurs in one plane (Fig. 1). The chain formation and the chain length are variable. Streptococcus equi ssp equi is a constant chain producer, other species are not. The chain length is shorter in artificial media than natural one. Young cultures are gram positive whereas the bacteria present in the pus and older cultures in the laboratory are often stained as gram negative. 

Streptococcal capsule is polysaccharide in nature. It can be subdivided into different antigenic types (e.g. S. agalactiae, S. pneumonae). However capsules of S. equi, S. pyogenes are made of nonantigenic hyalu-ronic acids containing repeating units of glucuronic acid and N-acetyl-glucosamine. Synthesis of the polymer involves the products of three genes, hasA, hasB, and hasC, which are all in the same operon.

Lignieres and Spitz first isolated the bacteria from the cattle with Actinomycosis like condition in Argentina in 1902. They referred them as ‘Actinobacilllus’. These findings were also confirmed by Nocard in 1902. Latter, the isolated bacterium from the cattle was named as Actinobacillus lignieresii, in memory of Lignieres. 

Properties of genus

1.   Morphology :  Actinobacillus are gram negative small rods, measuring 1.5 µm in length and 0.4 µm in width, occurring singly, in pairs or more rarely in chains. After isolation in the laboratory they may show pleomorphism varying from coccobacilli to filamentous forms. In gram stained smear they may show both bacillus and coccus form together, known as ‘morse code’ appearance (dots and dashes appearance, Fig.1). They are non-motile (both at room temperature and 37^oC), non-sporing and non-acid fast. The pili are found in A. pleuropneumoniae.

      Some of them (A. pleuropneumoniae) are capsulated. Whereas, slime layer is found in the surface of other species like A. lignieresii, A. suis, A. equuli.  This slime layer is related with stickiness of the colonies in the agar, enhanced resistance of the colonies to the chemical disinfectants, as well as, resistance of the bacterial cell to the antibiotics and desiccation.

2.         Actinobacillus are aerobic, microaerophilic or facultative anaerobic in nature. They are chemoorganothrophic having both respiratory and fermentative types of metabolism.

Corynebacterium diptheriae was first observed by Klebs in 1883 and described in details by Loeffler in 1884. So it is also known as ‘Klebs-Loeffler bacillus’. In 1888, Nocard isolated a similar type of bacteria from cases of bovine farcy. In 1894, Preisz described it completely and revealed its similarities with the diphtheria bacilli. Latter it was named as Corynebacterium pseudotuberculosis (Preisz-Nocard bacillus). Bollinger (1890) first reported C. renale from the cases of pyelonephritis in cows. Magnusson (1923) first described C. equi (Rhodococcus equi) form suppurative pneumonia of a foal.

Properties of genus

1.   Morphology

Corynebacterium are gram positive, pleomorphic bacteria ranging from coccoid to filamentous rods. The size varies from 0.5-0.6 µm by 1.0- 3.0 µm. Some of the species appear as packets of parallel cells (palisade arrangement) or show ‘V’ shaped form (Chinese letter arrangement) in the microscopic field (Fig.1and Fig.2). The cell wall peptidoglycan contains meso-diaminopimelic acid (meso-DAP). The arabinose and galactose are major cell wall sugars. Short-chain mycolic acids (corynomycolic acids, 22–36 carbon atoms) are present. This kind of cell wall structure is impermeable to the hydrophilic compounds. However, the ‘porin’ present in the cell wall sometimes helps in import of the hydrophilic substances. Mycolic acid containing cell wall helps in intracellular survival within the macrophages. Corynebacterium is non acid fast, non-sporulating, non-capsulated and non-motile bacteria (except C. aquaticum)
.

Properties

1. Bacteroides, Dichelobacter and Fusobacterium are major gram negative anaerobes isolated from human and animals. Other gram negative anaerobes are listed below (Table-1).

       2.   They are tolerant to oxygen in comparison to strict anaerobes. They do not die after oxygen exposure

       3.         They naturally inhabit the intestine and mucosal surfaces of human and animals. Majority of them are opportunistic pathogens. Often they cause mixed bacterial infection along with aerobes. Aerobes remove oxygen and create an anaerobic condition favourable for their growth. Aerobes may also supply other growth requirements. For e.g. Porphyromonas asaccharolytica requires vitamin K for its growth, supplied by another bacterium, not the host.

The word ‘chlamydia’ comes from the Greek word ‘chlamys’ which means, “cloak draped around the shoulder”. This describes how the intracytoplasmic inclusions caused by the bacterium are “draped” around the infected cell’s nucleus. Chlamydia was first discovered by a Czech zoologist and parasitologist, Stanislaus von Prowazek in 1907 in Berlin, but scientists believe it was actively infecting people for centuries before its discovery. Because the symptoms of Chlamydia are similar to some other infections it was not identified as a sexually transmitted disease. Originally, because of its structure it was thought to be a virus. In 1963 it was recognized as bacteria rather than a virus.

Properties of genus

           They are poorly stained by Gram’s stain. Chlamydiae are readily stained by Castaneda (blue in appearance), Giemnez and Macchiavello (red in appearance) methods. However, Giemsa staining is preferable to stain the inclusions (Chlamydial micro colony) in the cell culture. Inclusion bodies of the Chlamydiae are basophilic in nature. Again, the staining of the inclusion bodies may differ depending on the species. In C. trachomatis, the inclusion bodies contain glycogen matrix and can be easily stained with iodine solution.

Materials Required

Fruit juice/ pulp, cane sugar, potable water, essence, citric acid, colours, preservatives, weighing balance, bottling and sealing facilities, hand refractometer, homogenizer etc.  

Procedure

    1.    Extract the juice as discussed in previous exercise.
    2.    Filter the fresh or preserved juice through muslin cloth.
    3.    Calculate the quantities of juice, sugar, water, acid (if required), preservatives, colour, essence etc. required for preparation of a known quantity of                      squash as per FPO specifications.
    4.    Prepare the beverage as directed by instructor
    5.    Pack the beverage in bottles 
    6.    Seal the bottles and label them
    7.    Take out one of the bottles and measure its TSS and titratable acidity.

In recent years, we are just experiencing a surplus production in cereals and oil seeds leading to self-sufficiency through green revolution and yellow revolution. However, shortage in the production of vegetables has drawn the attention for increasing the cultivation of vegetables to provide food and nutrition security.

Vegetables are being cultivated over an area of 49 million hectares with the production potential of 487 million tonnes in the world. This accounts for 2.85 per cent of total cropped area in the world. India is the second largest producer of vegetables next to China, sharing nearly 12 per cent of the total world output (Joshi and Shukla, 1997). Vegetables occupy nearly 8.02 million hectares with the production potential of 133.10 million tonnes in the year 2009 in India (Anonymous, 2009).

Bhendi (Abelmoschus esculentus (L.) Moench) is an important member of family malvaceae and commonly known as okra or ladyfinger in India. It is one of the most ancient and traditional vegetable crops grown in tropical and subtropical regions of the world (Martin and Ruberte, 1978). Bhendi is originated from tropical Africa with 2n = 8x = 72 or 130 or 144 chromosomes and is an allopolyploidy in nature (Joshi and Hardas, 1956; Suresh Babu, 1987). Martin (1982) reported that it behaves as a diploid. Under the genus Abelmoschus, there are 30 species in the old world and four in the new world (Joshi et al., 1974). Out of them, Abelmoschus esculentus, is the only species known to be cultivated. Bhendi is being raised in India in an area of 0.44 million hectares with an average production of 4.52 mt with the productivity of 10.27 t/ha (Anonymous, 2009).

Crossandra belongs to family Acanthaceae. It is also known as Kanakambaram in Tamil or Kanakambara in Kannada and Fire cracker in English because of cracking sound during opening of seed pod. Crossandra is derived from Greek word “krossoi” meaning fringe and “aner” meaning male i.e. fringed anthers. Crossandra is an evergreen shrub and one of the important loose flower used for adornment. The flowers are commonly grown for flower adornment in the form of garlands, venis and gajras. Though it is not fragrant, flowers are very popular because of its attractive bright colour, light weight and good keeping quality. These are used for making garland, either alone or in combination with jasmine flowers. Using crossandra flowers in combination with jasmine is becoming increasingly popular in India, particularly in southern parts, because the jasmine flowers provide colour contrast and the desired fragrance. Crossandra varieties show a remarkable range of colours, varying from orange, pink, red, yellow and double coloured blue-type with white throat.

ORIGIN AND DISTRIBUTION

Crossandra is native to Indo-malaya region. They are all native to sub-tropoical regions including India, Southeast Asia, Africa, and Madagascar.

Crossandra Salisb is a genus of about 50 species which are shrubs or herbs from Tropical Africa, Madagascar and Arabia, where it is grown as a perennial shrub. Crossandra undulaefolia Salisb. (Syn C. infundibuliformis Nees) is a native of East Indies. However, it is sometimes considered to be native of south India and Ceylon. C. guinensis is native of east Africa while C. nilotica has its origin in east Africa and Mozambigue. C. flava is a native of tropical west Africa.

The crossandra plants are distributed in tropical as well as subtropical regions of the world such as south Asia, South America, South Africa and Madagascar. In India, it is commercially cultivated in southern states of Karnataka, Tamil Nadu and Andhra Pradesh (Singh, 2006).

Hantaviruses have been responsible for a variety of human illnesses particularly haemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). There are currently 47 recognized sero/genotypes of hantaviruses with considerable geographic diversity. Each hantavirus type appears to be specific to a different rodent host. The different hantavirus types are associated with different types of disease both in terms of target organs and disease severity. HFRS is primarily a disease of the Old World while HPS is a disease of New World. Although the disease may have first been recognized as early as 1000 years ago in China, it affected >3000 United Nations Soldiers during Korean war (1950-1953). Now it is reported that hantavirus affect as many as 2 lakhs people each year in Asia and Europe. The agent of this virus remained unknown until 1978 when Lee and his associates isolated and named Hantaan virus, after a river in South Korea. Other viruses antigenically related to Hantaan virus were characterized and placed under the genus Hantavirus and family Bunyaviridae.

Over the past few decades, the sharp increase of incidences of hantavirus disease in humans throughout the world has been reported. There are 47 recognized hantaviruses with considerable geographic diversity. But the number of hantavirus virus types recognized continues to grow. Hantaviruses cause persistent infections in rodent reservoirs which directly impact transmission of these zoonotic agents between rodents and from rodents to humans. Environmental, 127 demographic and physiological factors likely interact to mediate responses to hantaviruses in natural rodent populations. Although not much work has been carried out, comparisons of human and rodent immune responses to hantaviruses may provide insights into why hantaviruses often are fatal for humans but cause only persistent infections in rodents.

Crimean Congo hemorrhagic fever (CCHF) was first reported in the 12^th century as a hemorrhagic syndrome in present day Tajikistan. However, in the modern era, the first outbreak of the CCHF was reported in 1944-1945 in the Crimea region with more than 200 cases and the disease was called Crimean Hemorrhagic Fever. Ten years later in 1956, the virus was isolated from a febrile patient in Belgian Congo and this isolate was noted to have the same antigenic structure with the Crimean strains. For this reason, the virus was called Crimean Congo Hemorrhagic Fever. Nowadays, outbreaks of CCHF have been documented in Africa, the Middle East, Eastern Europe, and Western Asia including India. CCHF is a severe hemorrhagic fever with a case fatality rate of up to 50%.

Etiology: It is a tick-borne viral disease belonging to the family Bunyaviridae, genus Nairovirus. Like other Nairoviruses, CCHF virus is an enveloped single stranded negative-sense RNA virus and its tripartite genome consists of a small (S), a medium (M) and large (L) segment which encode for the nucleocapsid protein (NP), the envelope glycoproteins G1 and G2 and an RNA-dependent polymerase, respectively. The virus is transmitted to humans through the bite of infected ticks or by direct contact with viremic animals or humans. Infected humans can spread the disease via close contacts which may result in community outbreaks and nosocomial infections. It is an important human pathogen and could be used as a bioterrorism agent.

Pathogenesis: The pathogenesis of CCHF is not well understood. A common pathogenic feature of hemorrhagic fever viruses is their ability to disable the host immune response by attacking and manipulating the cells that initiate the antiviral response. This damage is characterized by marked replication of the virus together with dysregulation of the vascular system and lymphoid organs. Endothelial damage contributes to hemostatic failure by stimulating platelet aggregation and degranulation, with consequent activation of the intrinsic coagulation cascade. DIC is noted as an early and prominent feature of the disease process. In another study, the levels of interleukin IL-1, IL-6, and TNF-alpha were higher among patients who subsequently died as compared to survivors. The DIC score was higher among fatal cases, correlating positively with IL-6 and TNF alpha levels, and negatively with IL-10 levels. These findings demonstrate that proinflammatory cytokines play a major role in pathogenesis and mortality of patients with CCHF.

Synonyms: Calf scour, white diarrhea, septicaemia of calves

Colibacillosis is one of the important diseases in new born calves, piglets, lambs and foals caused by E. coli and characterized by marked postration, profuse diarrhea and septicaemia.

Etiology: Colibacillosis is associated with pathogenic serotypes of E. coli. Certain serotypes cause diarrhea and others cause septicaemia.

(a)  Enterotoxigenic E. coli: is the most common enteropathogen that causes diarrhea in new born farm animals. It causes bacteria by adhering to, colonizing and producing enterotoxins in the small intestine. They are not invasive. The enterotoxins produced by E. coli are of two types: heat stable (ST) and heat labile (LT).

(b)  Enteropathogenic E. coli: they attach tightly to the epithelial cells of the villus of small intestine. They do not produce toxins and seldom invade the intestine.

(c)  Enterohaemorrhagic E. coli: They are Shiga toxin or verotoxin producing strains of E. coli. They are not an important cause of diarrhea in farm animals but some produce diarrhea in calves. E. coli O157:H7, one of the important enterohaemorrhagic E. coli strains cause a broad range of clinical disease in humans including diarrhea in humans and haemorrhagic colitis and highly fatal haemolytic-uremic syndrome in children. 195

Glanders is a contagious, acute or chronic, usually fatal anthropo zoonotic disease of Equidae caused by Burkholderia mallei and characterized by serial development of ulcerating nodules that are most commonly found in the upper respiratory tract, lungs, and skin. The first recorded description of glanders is from the third century from Aristotle. In 1664, glanders was recognized as a contagious disease and in 1830, it's zoonotic potential was suspected. In the late 1800's, the Mallein test (1891) was developed for diagnosis of glanders. By 1910, the U.S., Canada and Great Britain all implemented glanders controlprograms. B. mallei was eradicated from the United States in 1929.

Etiology: It is caused by Burkholderia mallei. It is a straight or slightly bent Gm - non-spore forming, non-motile rod. The organisms in old culture appear as pleomorphic. The organisms can grow in ordinary media but addition of defribinated horse blood or glycerol accelerate the growth. Colonies have hop like odour and slime consistency. The organisms are readily destroyed by direct sunlight and most of the disinfectants. They can survive for 20 days in water and 6 weeks in contaminated stable. This organism is closely related to the agent of melioidosis, Burkholderia pseudomallei.

Susceptible hosts: The most susceptible hosts are horses, mules and donkeys. Infections can also occur in dogs, cats, goats and camels; cats may be particularly susceptible. Hamsters and guinea pigs can be infected in the laboratory. It is an occupational /professional hazard to human being. Laboratory samples are highly infectious to humans. Infection have been observed in sheep and goats. Guinea pigs, rabbits and field mice may be infected fatally. Cattle and pigs are absolutely resistant.

Geographic Distribution: Glanders is seen in some Middle Eastern countries, the Indian subcontinent, Southeast Asia, parts of China and Mongolia, and Africa. Sporadic cases are also seen in South America. Sporadic cases of glanders were identified between 1985-86 to 1990-91 from the states of Haryana, Himachal Pradesh and Punjab. Since reemergence of glanders in July - August 2006 in and around Pune and Panchgani area of Maharastra, several cases have been reported among equines of different states viz., Andhra Pradesh, Uttar Pradesh, Uttarakhand and Punjab. During the year 2006-07, National Research Centre on Equines, Hissar tested 4395 samples and 97 were detected positive and B. mallei was isolated from 8 of these cases.

Synonyms: Circling disease, Meningoencephalitis, silage disease

It is an infectious fatal disease of wide range of animals and man characterized by encephalitis. It also causes abortion, endometritis and repeat breeding in farm animals. Historically, Listeria was first isolated in 1926 from a natural disease of rabbits characterized by mononuclear leucocytosis and therefore named as Bacillus monocytogenes by Murray and coworker at Cambridge. Later, Pierie who isolated similar bacillus from liver of gerbils in 1927 named it Listerella hepatolytica in honour of surgeon Joseph Lister and finally renamed it Listeria in 1940 due to taxonomic reasons.

Etiology: The disease is caused by L. monocytogenes. The genus Listeria consists of a group of Gm + bacteria of low G+C content closely related to Bacillus, Clostridium, Enterococcus, Streptococcus and Staphylococcus. Out of 6 species reported, only L. monocytogenes and L. ivanovii are considered virulent. Human cases of L. ivanovii infection are rare whereas L. monocytogenes is an important food borne pathogen. L. monocytogenes has been isolated from a variety of food products. Meat, poultry, dairy and vegetable products have been implicated as vehicles of listeriosis. The organism can be isolated from faeces and silage. The organism can be easily destroyed by ordinary disinfectants but may survive in soil and silage for a considerable period of time.

L. monocytogenes is small, coccoid with a tendency to occur in chains. It is aerobic or microaerophilic. It grows on ordinary media within a temperature range of 4-42°C. Growth is improved by addition of glucose, blood or liver extract. Colonies are β haemolytic on blood agar. It ferments glucose and salicin producing acid without gas. Lactose, maltose and sucrose are fermented slowly or not at all and mannitol is not fermented. It is catalase +. It shows tumbling motility when grown at 25°C but at 37°C is non-motile. It is because peritrichous flagella are produced by the bacillus optimally at 20-30°C but scantily or not at all at 37°C.

Indian horticulture has shown impressive impact on production, productivity and profitability. Currently, the total production of horticultural produce is 214.7 million tones from the 9% of total cultivated area in India, which contribute 30.4% to GDP of agriculture (Singh, 2010). In world perspective, India is second largest producer of fruits (68.5 mt) from 6.10 m ha area and contributes 11.2% in global fruit production. Vegetable crops occupying 8.0 m ha have the production of 129.1 mt (Table 1). However; India is the largest producer, consumer and exporter of spices and spice products in the world and produce more than 50 spices. The spice production in India is the order of 4.14 mt from an area of about 2.63 m ha. India is also the leading producer of plantation crops in the world and contributes 22.34% in coconut, 25% in cashewnut and 55% in arcanut. Commercial floriculture sector has recorded fast pace of growth during the last decade. During the last decade area under floriculture has expended to 1,67,000 ha with production of 9,87,000 MT of loose flower and 4.8 million cut flowers (Singh, 2010). The over all percent share of fruits and vegetables to their total production and contribution of different states for production of fruits and vegetables are repicted in Fig. 1 & 2. From the above fact, it is indicated that the production of horticulture produce has increased manifold but the gap in demand and supply continues simultaneously and is hardly sufficient and meets only 46% of national demand. Hence, there is a strong need to increase the production and productivity through crop diversification.

Agriculture in India is one of the most important sectors of its economy. It provides livelihood to almost two thirds of the work force in the country and accounts for 18% of India’s GDP. About 43 % of India’s geographical area is used for agricultural activity and large number of production systems are in practice in different parts ofthe country. In pre-independence era (before the 1950s), agriculture in India was a system of harnessing nature for the sustenance of human beings, similar to the presently defined organic farming. Some countries have moved away from inorganic to organic farming yet it is not possible for India to depend entirely upon this system of farming due to large population. Total availability of plant nutrients from organic sources is projected to be 7.75 million tonnes by 2025 (Tandon, 1997) against the total requirement of37.50 million tonnes (Katyal, 2001) for 1504 million population (Sekhon, 1997). Thus nutrients supply through organic sources alone would result in deficiency of about 30 million tonnes of nutrients. Hence, it is imperative to use both organic and inorganic sources of plant nutrients enhance food production for the increasing population (Mahajan et al., 2007). In India the contribution of organic sources was 80-100 per cent in 1949-50 and reduced to about 32 per cent in 1993-94 and 20-25 per cent in 2004-05. So, it is imperative to enhance organic sources to meet total nutrient consumption. Following independence, rapid population growth in India placed great pressure on land and on these traditional farming systems; huge demands for food grains led to increased use of fertilizers and pesticides to boost production. Still a negative balance of about 8 million tones of NPK is foreseen in 2020, even if we continue to use chemical fertilizers, maintaining present growth rates of production and consumption. The most optimistic estimates at present, show that only about 25-30 per cent nutrient needs of Indian agriculture can be met by utilizing various organic sources. Many of the gains in production during the last 4-5 decades resulted from the “Green Revolution,” a campaign of technological interventions in agriculture widely adopted by farmers in developing countries. Expansion of irrigation to cover rain fed areas, popularization of hybrids/ transgenic varieties of crops, and use ofsynthetic chemical fertilizers and pesticides were the maj or technologies promoted. This paid rich dividends in India, quadrupling food grain production from 50 million metric tons in 1950-51 to 211 million metric tons in 2001-02, and enabling India to become self-sufficient in food grain. Now a second green revolution is also in the offing, to boost agricultural production and meet the estimated requirement of 337 million metric tons.

Balanced crop nutrition is a most reaJized critical factor in allowing crops to give their full yield potential. The application of macro and micronutrients through manures and fertilizers to achieve this balance is an integral practice in modern crop production system. Macro and microelements have long been recognized as being associated with changes in the level of many diseases and yield and /or quality of crops. Three major elements N, P, and K are the most studied nutrients which chiefly affect relative resistance of crop plants to various diseases. Others macro/micro/beneficial nutrients including Ca, Mg, S, Mn,Te, Zn, Mo, Si, Bo and Cu have shown varying degrees of disease suppression/induction on many crop species under various environmental conditions. Crop nutrition influence plant health through: i. affecting the growth, reproduction, virulence, and survival of pathogens; ii. resistance and tolerance, predisposition and escape in the host crop; and iii. root exudates and microbial interactions facilitatingbiological control. Balanced crop nutrition can protect crops from pathogens by: i. avoiding plant stress, which may allow crops to better withstand the attack of pathogens and ii. manipulating nutrients to the advantage of crops and disadvantage of the pathogen. The modern intensive agriculture which mainly relies on chemical inputs (fertilizers and pesticides) and fertilizer responsive HYVs (high yielding varieties) has led the self sufficiency in food production in India and several other countries of the world. But, the indiscriminate and imbalance use of chemical fertilizers along with exhaustive cropping initiated several second generation problems including widespread micronutrient deficiencies and increased attack of several insect-pests and pathogenic diseases. The excessive use of nitrogen and no or reduced application of phosphorus, potash and other micronutrients is creating conducive conditions for several crop pathogens and their insect vectors. This situation frequently results in serious crop losses during favourable environmental conditions for disease development. The specific role of macro and micronutrients in maintaining crop health, effect of their dose and form of application on suppression /induction of various diseases and interaction with other soil/ environmental factor (s) will be discussed in following sections.

Objective:To transfer DNA on nylon membrane by Southern blotting.

Background information

A Southern blot is a method used in molecular biology to detect a specific DNA sequence in DNA samples. Southern blotting combines transfer of electrophoresis-separated DNA fragments to a filter membrane and subsequent fragment detection by probe hybridization.

The British biologist Edwin Southern (Southern, 1975) discovered this technique the technique is known by his name. Southern blotting technique uses digested genomic DNA with restriction enzymes. Southern blotting technique may be used to identify the gene copies number in a genome. A probe that hybridizes only to a single DNA segment that is uncut with restriction enzyme will produce a single band on a Southern blot, whereas multiple bands will likely be observed when the probe hybridizes to several highly similar sequences (e.g., may be due to sequence duplication).

In the southern blotting technique a short DNA probe is used that matches based on complementary DNA sequence fragment on filter membrane. It proves that the DNA fragment on membrane contain specific sequence for which DNA probe is prepared. When DNA is transferred on the membrane from gel it permits binding of radioactive/Biotin labeled hybridization probe to the restricted DNA. Southern blotting is also important for autoradiography.

Southern blotting is an important molecular biology technique that may be used for homology based cloning, screening a DNA library, screening of cloned DNA fragments and to identify methylated sites in genes.

Objective: To quantify aflatoxin content in given sample by Indirect competitive ELIS

Background information:

Enzyme linked immuno sorbent assay (ELISA) is a common biochemical technique that uses the principle of solid-phase enzyme immunoassay (EIA) for detection of substances mainly antigens in a liquid or wet sample.

ELISA is a very popular technique that is used for diagnostic purpose in health sector, plant protection and also for quality test in food and other industries. This technique applies the principle of antigen-antibody reaction on a solid surface. The attached antibody is linked to certain enzymes and in the end of reaction by addition of substrate that performs enzyme-substrate reaction and makes product that has some signal mostly color change and based on intensity of color the qualitative as well as quantitative estimation of antigens can be done using ELISA reader coupled with spectrophotometer.

In ELISA technique one antibody should be specific to certain antigen. For reaction of ELISA the ELISA plates are used that is also known as microtiter plate made-up of polystyrene. The sample to be tested for ELISA contain unknown amount of antigen to be detected, this sample containing antigen is immobiliz d on a solid support like polystyrene microtiter plate in two different ways; first is non-specific where antigens adsorbed to the surface and second is specific where the antigens of sample are captured by specific antibody to the antigen, like used in sandwich ELIS Once the antigens are immobilized non-specifically or specifically the detection antibody should be added that makes precise antigen-antibody complex. The detection antibody may be either covalently linked to certain enzyme or may be detected by another secondary antibody linked to bioconjugated enzyme. During ELISA steps several proteins or antibodies may non-specifically bound that can be removed by washing with mild detergent solution in between of each ELISA step. For washing of ELISA plates, ELISA plate washer may be used that mechanically wash the ELISA plates. At the end of ELISA the final wash is given and substrate is added that produces visible signal in the form of color change that indicates the presence of antigens in the sample and further quantification may be done using ELISA reader coupled with spectrophotometer.

1. Introduction

The global population is very cautious about gaining weight and diabetics. Calorie less and sugar free substances are gaining momentum in food sector. The miracle plant stevia is very fit in this scenario as it is both zero calorie and sugar free and one more additional benefit that it is completely natural. Stevia rebaudiana Bert. belonging to the family asteraceae has been used in many countries for thousands of years as a source of natural sweetener eg., in Paraguay and Brazil Central America, Thailand, Korea and China (Megeji et al., 2005, Sivaram and Mukundan, 2003; Jain et al., 2009). It is also known as sweet herb, sweet leaf, honey leaf, candy leaf, honey yerba (Carakostas et al., 2008) and meeti tulsi. It possesses an extensive root system and brittle stems producing small, elliptic leaves. In natural conditions S. rebaudiana grows in a form of a shrub and reaches even 1 m of height. Leaves are the major economic part. They are sessile and oppositely arranged, lanceolate to oblancoelate in shape, and are serrated above the middle. Trichome structures on the leaf surface are of two different sizes, one large and one small (Shaffert and Chetobar 1994). The white florets are, borne in small corymbs of 2–6 in number. Corymbs are arranged in panicles. Dr. Moises Santiago Bertoni discovered this plant in 1888 at Paraguay. In 1905, the plant was scientifically named as S. rebaudiana after a Paraguayan chemist Dr. Rebaudi. (Gupta et al., 2013). The active components of Stevia i.e., steviol glycosides (SGs) includes rebaudioside A (Reb A), rebaudioside C and stevioside (ST) that are 250-300 times sweeter than sugar (Chalapathi & Thimmegowda 1997). Stevia is a short-day plant and its flowering is induced when days are shorter. Long photoperiods stimulates leaf growth and steviol glycoside content. The plant can survive only mild winters of its native regions. It cannot survive in waterlogged areas. Stevia extracts can be used in a wide variety of food and beverage applications. Individual usages and use levels may vary depending on the country. They act synergistically when used in combination with other sweeteners. The higher market demand favors the cultivation and commercialization of this particular species.

Dioscorea L. commonly known as yam is the largest genus in the family Dioscoreaceae with 602 species distributed in the tropical and subtropical regions. It is an important food crop next to cereals and grains due to high yield storage of carbohydrates which form an important place in the dietary habits of small and marginal farmers especially in the food security of tribal population. The tubers are rich source of various secondary metabolites like Diosgenin, a commercially important bioactive sapogenin used as a precursor in the manufacturing of sex hormones, oral contraceptives and other pharmaceutically important steroidal drugs. Despite of its huge diversity only few species are recognized to be useful for medicinal and edible purposes. About 50 species of Dioscorea are distributed in India. The North East India, one of the hotspot of biodiversity is particularly rich in tropical root and tuber crops. Dioscorea species are in luxuriant growth in wild habitat in this region. The present study mainly addressed to explore the ethno medicinal uses, phytochemical analysis and also focused on safe conservation of sixteen species of Dioscorea found in this region.

1. Introduction

The North east India (located between 87Ú32’E to 97Ú52’E latitude and 21Ú34’N to 29Ú50’ N latitude) forms a distinct part of the Indo-Burma hotspot which rank the 6th among 25 biodiversity hotspot of the world is climatically, ecologically and ethnically very diverse. The region is largely dominated by tribals such as Naga, Khasi, Mizo, Miri, Adi, Aka, Apatani, Maripa, Mushard, Garo, Tagin Naga and Singhpho who are sociocultural different. The North east region, besides having large floral biodiversity, is yet not fully explored. The forest resources available in this area are most often ill managed due to lack of awareness and anthropogenic activities. Various wild roots and tuber crops are consumed by the indigenous group of North East India which have very less scientific documentation although. As wild tuber crops available in North East India, Dioscorea species play a prime role in providing food and medicinal requirements for the indigenous communities of this region. Hence the present paper focuses on the ethnobotanical importance and qualitative screening of few important phytochemicals present in the various species of Dioscorea, their conservation strategies and sustainable utilization in North East India.

1. Introduction

Medicinal plants are well known for their secondary metabolites which are alternatively called as active principles responsible for curing of diseases and disorders. India is a biodiversity rich country belongs within 12 mega diversity zones of the world and possesses four biodiversity hot spots, 8 phyto-geographic regions and 10 vegetation zones (Khandekar and Srivastava, 2014). This subcontinent holds 47000 different species of plants out of which 8000 plants are medicinal in nature (Hamilton, 2004, Owolabi et al., 2007). High rate of endemism and 426 habitats for specific species are the unique resource of the country (BSI, 2009; Khandekar and Srivastava, 2014). Still majority of the herbal raw materials are wildcrafted and hence habitat destruction and wildcrafting pose a serious problem to the natural population particularly where roots are the targeted plant part as the percentage of root yielding medicinal plants are higher in the subcontinent. Since these plants are purely industrial and not having alternative uses the commercial production is not flourishing at a higher pace. Still the production of medicinal and aromatic plants in India has reached 1031000 tonnes from 634000 hectares.

In the post-CBD regime with global developments in aspects of Plant Genetic Resources and Intellectual Property Rights, the outlook towards these lesser exploited species has been changed to bioprospecting from collection and documentation.Here lies the importance of value addition in medicinal plants. Value addition means a change of state of the produce which will give a manifold return than the additional investment. Value-added products can be obtained through processing of raw herb or crude drug which will improve its look and also increase its quality, longevity, efficacy and obviously the return.