eChapters

Giant granadilla, Passiflora quadrangularis L. (syn. P. macrocarpa M.T. Mast.) is the largest fruit in the genus Passiflora. With more than 450 species, Passiflora is the most important genus of family Passifloraceae. It is further divided into 24 subgenera (Killip, 1938). Most of the species producing an edible fruit belong to subgenera Passiflora and Tacsonia. Many species have ornamental interest because of unique and spectacular flowers, or are used for their sedative, antispasmodic, antibacterial, and insect-resistant properties.

The Andaman and Nicobar group of Islands, popularly known as the Bay islands, consists of 572 islands, islets and rocks, situated off the Eastern coast of India. The Islands are covered from coast to coast with an almost impenetrable growth of luxuriant tropical rain forests. The luxuriant growth of dense forests with tangled mass of climbers, lianes, canes and plant communities provide an additional source of income. Many species of bamboos, bushes, shrubs and stunted trees have tremendous values (Mondal, et al 2000). Most of the diversity is still collected from wild forest habitats largely composed of trees, shrubs and other perennial vegetations. Underutilized fruits provide food, nutrition and sustenance to the natives. Broadly, such underutilized diversity in edible fruits falls into four categories (Groot et al 1993).

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).

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.

Plants yielding oilseeds are economically important in India next only to food crops and play an important role for sustainability of  cropping systems and soil health. Oilseeds scenario in the country underwent a sea change in  last fifteen years. India changed from net importer in  1980s to a net exporter  during  early 1990s. Again, it is back to net importer importing more than 40 % of its annual edible oil needs. Country’s demand for edible oils is  rising to double  the current level of 4% (as against productivity growth of 2% in 1986-2001) in  next 12 years (Hegde 2004). To meet  challenges of oilseeds production, there is  need to adopt multi-pronged strategy which involves enhancing production through area expansion and productivity improvement through improved technologies and value addition . As a progressive step in this direction of self sufficiency, there is  need to identify alternative oilseed trees/plants which can be grown in wastelands. There are more than 300 different kinds of tree species which bear seeds  rich in oil and  introduction of simarouba is an important step in this direction. National Oilseeds and Vegetable Oil Development (NOVOD) Board under Ministry of Agriculture  identified simarouba as a potential Tree Bearing Oilseed (TBO) for popularization in India and placed it in  first place in their list of importance.

Tamarind (Tamarindus indica) or Imli is also called  Indian Date. It is a large broad leaved, tropical tree found in India and many parts of Asia.  Tamarind is native to tropical Africa and grows wild throughout  Sudan. It was introduced to India so long ago that it is now reported as indigenous. Sometimes during  sixteenth century, it was introduced into America and today it is widely grown in Mexico.
 
There are large areas of marginal and waste lands, which are not suitable for cultivation of fruits like banana, citrus, sapota, litchi, mango, pomegranate etc., either due to poor quality of soil or lack of water resources. Such lands are suitable for  cultivation of underutilized fruit crops like tamarind which is not so popular among  farmers due to following reasons:

Karonda is an indigenous, under utilized fruit of India. It is a hardy multipurpose horticultural bush flourishing well without much care in arid and semi-arid areas. At present ,emphasis is being laid on protection and  production value of karonda plant. It is grown as hedge for beautification which  serves as one of the best bio-fencing materials because of  thorny  nature. It is also grown as an ornamental plant due to its beautiful cherry like fruits. Karonda plants are useful in many ways as detailed  below:
 
Fruit: Karonda fruit is a rich source of iron and contains a fair amount of vitamin C, and therefore very useful for curing of anaemia and has antiscorbutic properties. Enthomedically,  fruits are used as an astringent, antisorbutic and as a remedy for biliousness. Mature fruit contains high amount of pectin  and therefore, besides being used for making pickles and chutney, it can be exploited  for making jelly. Raw fruit can be used for making chatney.

Leaf: Karonda leaves are palatable and contain a fair amount of nutrient which are browsed by sheep, goats and camels in arid and semi arid areas.If fruits fall on ground, enrich soil by adding organic carbon and other mineral nutrients. It reduces evaporation  from  soil underneath due to dense foliage. Leaves  are used for feeding silk worm.  Leaf decoction is used against intermittent fever, diarrhoea, oral inflammation and ear ache.

Morinda citrifolia L is a unique horticultural plant belonging to Rubiaceae family. It has a tremendous demand because of its high medicinal value. Increase in demand has led to commercial farming of the tree. Noni is an ideal plant for mixed farming with other horticultural plantations. There is concurrent efforts to select early bearing plants with big size and fruits.  Noni can be grown in any type of soil under adverse climatic conditions.  Crop Improvement, nutritional requirement, water requirement, pest and disease management are the research priorities in Morinda citrifolia.

Indian Noni (Morinda citrifolia) is popularly known as Indian mulberry belongs to Rubiaceae family.  It is also called great Morinda, Cheese fruit, Mouse’s Pine Apple, Nono, Jumbie bread fruit, Hog apple. Noni was one of the most widely used medicinal plants in Polynesia prior to European contact, and continues popular among modern population. Noni is commonly known as canary wood in Australia, Kura in Fijii, mora de la India in spanish, nono in Tahiti and Nin in Marshall Island. Medicinal values of Noni were known to man many centuries ago. Uses of Noni were mentioned in Indian ethnopharmacology and ayurvedic medicines. Noni is grown as medicinal plant in most of  South Indian temples as sacred plant like basil (Tulasi). In India, it is called by several names in different  regional languages like nuna, manjanathi, manjanuna in Tamil,  molugu, mogal, bundamaddi in Telugu, kakaiplam, kattapitalavam, mannanatti in Malayalam, tagatemara, haladipavete in Kannada, Ach Al in Hindi, Paphan, Achchhulca in Sanskrit, Aseti, Nagkura, Mundari solidaru in Marathi.

Mango is the choicest fruit of tropical world. Originated in Indo-Malayan region (Mukherjee, 1985), more than one thousand varieties are under commercial cultivation in India (Mukherjee 1949). South Indian varieties of mango are distinct (Yadav and Singh, 1985).  Naik and Gangolly (1950)  described 135 South Indian varieties, taking fruit character as the main criteria. North Kerala experiencing humid tropical climate is an important zone of variability of mango (Kannan, 1982). Polyembryonic mango cultivars like ‘Vellaikolamban’, ‘Kurukkan’ and ‘Bappakkai’ are traditionally grown here. Over the years, there is erosion in  gene pool of rich varietal wealth due to deforestation, urbanisation and large scale rubber cultivation in Kerala. Establishment of field gene bank is an important ex situ conservation strategy. Systematic attempts to conserve  genepool  resulted  in collection of  more than 1266 varieties in various field gene banks in our country (Chadha, 1976). Field Gene Bank (FGB) has the advantage of being continuously evaluated and desired accessions can immediately be utilized directly or in breeding programmes. Field gene bank very often represents only a fraction of variability of the gene pool and  enrichment of the collection is always required for capturing  available diversity.

Spine gourd or teasle gourd (Momordica dioica : Roxb Syn.Momordica roxburghii G. Don, M. wallichi, M J Roem) is a rhizomatous, perennial and distinctly dioecious species of family Cucurbitaceae and  grows widely in many parts of India, mostly confined to  Eastern and South Eastern states. Vernacular names are kartoli,kakrol,meethakarela, padora, bhatt karela, palupagal, tumba, tumpai, golkandra, kankad, kankera, bara-karela, kankoda, kankodan, kantola and phalguni. In India it is mainly grown in Orissa, Bihar, and West Bengal .It is  found in nature in the Punjab, Uttar Pradesh, Rajasthan, Madhya Pradesh, Kerala and Maharashtra especially in areas with the least human interference. This is  a delicacy for its typical taste, attributed to high seed protein content. It also contains high amount of carotene (162 µg/100 g of edible portion) (Gopalan et al., 1982) and its tuberous roots have medicinal value too. It is a cheap source of vitamins and minerals (Bhuiya et al., 1977). This vegetable is gaining popularity  because of its high demand in  market. Certain limitations like lack of awareness among  farmers, non-availability of quality planting materials of standard varieties, unpredictable sex ratio in seedling progenies are arresting the expected spread of this nutritious vegetable (Ali et al., 1991).

Clasping stemmed Solena or diversely leaved Melothria or creeping cucumber (Solena amplexicaulis Lam. Syn. Bryonia amplexicaulis (Lam), Melothria heterophylla (Lour), Melothria angulata Chakrav) is an indigenous cucurbit vegetable occuring in nature nearby cultivated areas on hedges or in open fields In Greek Solen means’ a tube,pipe’ refering to the nature of its flowers. The vernacular names are Bon-kundari, kudari, makal, mahakal (bengali), gometti (marati), kanduri, kuduri (bundelkhand), bankakra (champa), gometi (gujarati, anatmul, mahakal, taarali, kaduri (hindi),makirla (chattirgarh), kaage mari balli (kanarese) etc. This is a perennial vine, dioecious in nature. Tender fruits are used as salad, curry and  fried vegetable. It has significant medicinal value also.  In tribal regions of Orissa, fruits of Melothria are considered as delicacy. Visualizing the delicate nature of its fruits, it has great potential as a salad crop in  future.

Syn.cordifolia Cogn.,C.indica Wight and Arn,Bryonia grandisL. Family.Cucurbitaceae) is an aggressively climbing vine that  spreads quickly over trees, shrubs, fences or other supports. It is also called  scarlet fruited gourd or little gourd. The name is derived from the Latin coccineus, meaning scarlet,in reference to fruit colour (Wagner et al.,1999). Vernacular names are kundru (hindi), kovakka, kova (malayalam), kovakkai, kovai(tamil), thondakayi (kannada), dondakaya (telugu). Coccinia shoot is a good source of calcium, iron, and fiber and has good texture (Anon., 2002). It is grown mostly in homestead farms for tender fruits in almost all regions of the country. It bears fruits almost through out the year where mild winter prevails. In regions where severe winter occurs, it bears fruit for 8-9 months. Although this is considered as a an under utilized vegetable, it is grown extensively in Chattisgarh, West Bengal, Bihar and Karnataka on a commercial scale and giving remunerative returns to  farmers. Availability of better cultivars and knowledge of  many other preparations and uses of this crop can propel its evolution from an under utilized species to an important horticultural crop in Indian Agriculture.

Chow-Chow [Sechium edule (Jacq.) Swartz] is used in many parts of Latin America, humid tropical regions of Central America and Southern Mexico. It is cultivated in South East Asia (India, Malaysia, Indonesia and Phillipines), Central and Western Africa, Central and South America (Brazil) and other tropical regions. (Dutta 1994). In India, local cultivars are commonly grown in coastal and low-hills (1000-2000m) of Maharashtra, Karnataka, and Tamilnadu. In Tamil, it is called “Seeme Kattrikkai” (Bailey, 1947). It is an important part of dietary system of tribals of  North East Regions. It is found in kitchen gardens of every tribal. It is found in almost all states and regions but maximum variability is found in Sikkim, Mizoram and Meghalaya (Yadav et al., 2005). Its variable fruits and roots, are important elements in diet of people. Chow-Chow is widespread and is an important export crop for  Latin American countries, much still need to be learned  about this crop (Rafael Lira Saade,1996). Chow-Chow is a single seeded fruit of  Cucurbitaceous family (MacGillivray, 1953). It is a perennial rooted vine that bears edible fruits (Thompson and Kelly, 1957). In subtropical and tropical regions, it produces large edible tuberous roots. It thrives under moderate temperature in  tropical or semi-tropical environment, though it can also be successfully grown under high temperature near sea level. Chow-Chow is a herbaceous perennial creeper (Choudhury, 1967) and is a robust grower in warmer months of year and during  cold weather of July and August  plant dies back temporarily. It has a viviparous type of germination (Patnaik, 1967). S.edule is called chayote, probably from  Greek ‘Sekos’ to  fatten in a fold because it was fed to hogs ( Bailey, 1963).

Basella (Basella alba syn Basella rubra) is also known as Poi, Ceylon spinach, Malabar spinach, Indian spinach or vine spinach. It is a popular leaf vegetable grown in almost all parts of India and widely grown in North-East and South India. Besides India, it is widely cultivated in tropical Asia and Africa. It is a climbing perennial plant, but is sometimes cultivated as an annual vegetable. The plant is succulent with tender leaves. It is a fast growing, productive leaf vegetable for home gardens and market growers. 

Composition
Young shoots and leaves of Basella are a rich source of calcium, iron, and Vitamins A and C.

Uses
Fresh tender leaves and stems are consumed as leaf vegetable after cooking. It is preferable to cook the leaves in soups and stews as half of soluble solids may be lost by boiling in water. Red cultivars contain a colouring matter in leaves, stems and ripe fruits reported as a dye for colouring food. Because of its mucilaginous nature of leaves and stems, it is used as poultice. Juice of leaves is prescribed against constipation, especially for children and pregnant women (Burkill, 1935).

Major cucurbits grown in India are cucumber, watermelon, muskmelon, ash gourd, pumpkin and squashes, snake gourd, ridge gourd, smooth gourd, bottle gourd, round gourd, bitter gourd, pointed gourd, ivy gourd,pointed gourd and oriental pickling melon. After independence,a lot of breeding work were done in these crops at many research institutes in the country which  resulted in  release of several high yielding/disease resistant varieties/hybrids.

Being warm season crops, cucurbits are tropical in origin, mostly in Africa, Tropical America and Asia. Flowering in cucurbits normally start in 40 to 45 days after sowing depending on weather conditions. Sequence of flowering follows a set pattern, namely the first 4 to 6 flowering nodes would bear staminate flowers and later pistillate flowers appear. Many sex forms are seen in cucurbits viz., monoecious, dioecious, gynoecious,trimonoecious, gynomonoecious and andromonoecious. Sex modification is also possible in cucurbits by exogenous application of plant growth regulators. GA₃ and AgNO₃ are used for inducing male flowers in gynoecious lines. Conversely,ethrel and TIBA  are used to promote greater number of female flowers. This kind of sex modification is more useful and practicable in  cucumber and bottle gourd where continuous and simultaneous flowering, fruit set and fruit picking take place.

In ancient days spices and herbs were valued as basic ingredients of incense, embalming preservatives, ointments, perfumes, antidotes against poisons, cosmetics and medicines and were used less in culinary preparations. A notable use of spices and herbs in ancient and medieval times were for the treatment of a variety of illnesses. Subsequently spices and herbs had come to be used to flavour food and beverages. In the course of time spices and herbs were shown to be useful not only for making the food lasting and palatable, but also in retarding or preventing rancidity and spoilage. This knowledge acted as a catalyst for the use of spices in a variety of processed foods. Based on the uses, herbs and spices are classified in to culinary, cosmetic and pharmaceutical. In the modern world spices have wide affiliation in the culinary art of people around the world, and are used in food industry for flavouring and seasoning, as well as in pharmaceutical preparations in the traditional systems of medicine and in beauty care. Spices and herbs are useful because of the chemical constituents contained in the form of essential oil, oleoresin, oleogum and resins, which impart flavour, pungency and colour to prepared dishes.

At present, approximately 1.4 million of the world’s species are described, but  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. India is one of the major centers of diversity in world. A small part of plant and their culture is considered as floriculture. India is bestowed with varied types of agro-climatic conditions conductive for growing a wide variety of ornamentals including flowers. India has a rich heritage of ornamental floriculture.

In rural and hilly areas there are different types of colourful flowers and foliage at different seasons round the year. All these colourful flowers and foliage are wasted under natural process. In spite of aesthetic beauty, all these natural resources are totally unutilized due to unawareness of their use. All these flowers are available in wide range of colours but mostly dominated by yellow. The entire seasonal colourful vegetations can be converted into value added products by using simple dehydration technique developed at National Botanical Research Institute, Lucknow. The technique is  suitable for dehydration of flowers and foliage. Present chapter will highlight how dehydration techniques can be utilized for preparation of value added products from seasonal unutilized floral vegetation of rural India.

Exacum bicolor, Roxb. commonly known as country kreat is  endemic to Peninsular India. It is a herbaceous perennial with attractive flowers and posseses medicinal properties. Plant is endangered today due to large scale habitat destruction.  Non- lodging nature of plant, attractive bi-colored flower bunches with a long flowering period and good field life offer great future for this plant to be domesticated as an attractive garden flower. Its ornamental value and medicinal properties are yet to be fully exploited.

India is bestowed with a wide array of flowering plants. It represents two of the 18 hotspots of biodiversity in the world; one being the Western ghats and other the North Eastern Himalayas. Nature has also blessed our India with  uniqueness of endemism. Of the 17000 flowering herbs distributed in nine phyto geographical regions of the country, 5700 are endemic. Exacum  bicolor Roxb. is one of the endemic species to Peninsular India. Plant is popularly known as Bharachirata and Habshi chirata in Hindi, Kannamthali in Malayalam, Dodda  chirayuta in Kannada and ceti in Tamil.

Barleria L. (Acanthaceae) is a pantropical genus of herbs and shrubs comprising about 300 species, occurring mainly in Africa and Asia. In India, the genus is represented by about 32 species of which 24 are endemic to India.  About 80 % of the species are found in Peninsular India. Many species of Barleria are of ornamental value and can be grown for their foliage and showy colorful flowers. There are certain indigenous species which show good growth performance in cultivation and have economic importance as ornamentals. Moreover, some species fall under IUCN categories of threatened plants which need immediate attention for their conservation. Considering the horticultural importance especially in landscape gardening and rarity of Barlerias, various species found in India are collected and cultivated through various methods in the Botanical Garden of Shivaji University, Kolhapur.

India is one of the 17 mega biodiversity hot spot of the world contributing to the worlds largest plant resource,from the long stretches of the Eastern Ghats on the east, the greater Himalayan range on the northern planes and Western Ghats on the west. The Eastern Ghats range is unique on its own way to host many valuable flora from time immemorial. The Eastern Ghats are spread over four states from the north east to south east. Among the four states Orissa is one of them consisting of diversified floral resource.

Orchids, more than any other plants, exert a mysterious fascination for most people. All the wild Orchids of tropical regions are highly puzzling and peculiar. These largest spectacular plants of monocot belongs to family Orchidaceae  consisting of more than 17,000 known wild species including 750 genera in the world and the present figure of hybrids among these touches around 80,000 (Rao, T.A., 1998). This family is cosmopolitan in nature having more species in tropics than the temperate regions. This family of monocotyledonous plants has evolved from prototypes of the lily and amaryllis family and is note worthy for the wide variety of its highly specialized and curiously modified forms.

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.

The Indian region is one of the world’s eight centres of crop plant origin and diversity, distinguished by Russian Scientist N.I. Vavilov. The region is home to a rich endemic assemblage of plants. Scrub jungles, grasslands, dry and moist deciduous forests, semi-evergreen and evergreen forests are the variety of vegetations along the Ghats. The complex terrain and heavy rainfall have helped to preserve flora and fauna in this region. The Western Ghats are an area of exceptional biological diversity and conservation interest, and are “one of the major Tropical Evergreen Forest Regions in India”.  This region is extremely rich in floristic diversity and most of the species are not exploited so far. There are many underutilized endemic flowering plants found in Western Ghats having ornamental value. 

Flora of Western Ghats
 The Western Ghats cover only 5% of India’s total geographical area but contains more than 27% (4000 species) of  country’s total plant species (Nayar, 1996). The Western Ghats, also known as the Sahyadris, extend about 1600 km. starting in North from Tapti river and going down to Kannyakumari in the South. These ranges run parallel to West coast hardly 40 kilometres away on an average from shoreline. The Western Ghats run through states of Maharastra, Goa, Karnataka, Tamilnadu and Kerala. Elevation of Western Ghats is in  900 – 1500 m and in some places goes beyond 2000 m. The Western Ghats form major watershed in Peninsular India and  58 major Peninsular Indian rivers originate from them.

Yam bean(Pachyrrhizus erosus), a leguminous crop, native of North America is cultivated for its edible tubers. Though six species of Pachyrrhizus are grown for tuberous roots, P. erosus, P. tuberosus and P. aphipa are important.

While P. erosus(L.) Urban(2n = 22) has pods of 7.5-13 cm long, P. tuberosus has longer pods of 13-30 cm. P. aphipa is a non climbing plant with fusiform tubers and this species is mainly cultivated in Bolivia.  Synonyms for P. erosus are P. angulatus, P. bulbosus and Dolichus erosus.  P. erosus is the species commercially cultivated in India.

Wild forms of yam bean are seen in Mexico and northern parts of Central America, where its cultivation is reported during pre-Coloumbus period.  Yam bean is believed to have spread from Mexico to Philippines, Amboina before 17th century.  Now, yam bean is cultivated in China, Thailand, Singapore, India and Hawaii.

In India, it is grown in Bihar, West Bengal and Orissa.  In Hindi, it is called as “Miskri kand” and in Bihar as “Kesaru”.

Edible legumes are excellent sources of dietary protein and oils. Winged bean, otherwise known as Goa bean, Manila bean, princess pea, asparagus pea or four angled bean is becoming popular as a tropical legume vegetable. It is a multivitamin and multimineral packed legume. This wonder vegetable was considered as the vegetable of the twentieth century. It is also known as ‘soya’s rival’ or ‘God sent vegetable’. All parts of the plant are edible namely leaves, flowers, immature pods, immature seeds, mature seeds and tubers. It is also named as ‘a supermarket on a stalk’ because the plant combines the desirable characteristics of common bean, pea, spinach, mushroom, soya bean and potato. Its vernacular names are:  Bengali, Chara-koni-sem or lakar-sem; Tamil, Morisuavarai; Kannada, Shambe kayi; Malayalam, Chaturapayar or irachipayar and Marathi, Chavdhari ghevda.

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.

Dioscorea alata is commonly called greater yam or larger yam or water yam.  This is the most widely distributed species of yam. This species originated in South East Asia, probably in Burma. From there, it first spread to India, Malaysia, Indonesia and the eastern portion of South East Asia.  Later it served as food for voyagers and thereby spread to other parts of the tropics.  Immigrants from India and Malaysia introduced it to Madagascar, from where it was partially introduced into East Africa and Portuguese and Spanish voyager traders of the 16th century probably introduced it into West Africa and later to West Indies.

Coleus, commonly known as Chinese potato, is a minor tuber crop of the tropical regions of India, Indonesia, Malaysia, Sri Lanka and Africa. It is considered as a native of India , where its cultivation is mostly confined to the southern states. In Kerala, it is commonly known as koorka or cheevakizhangu. In Malaysia it is called ubi kemili, kentang kechil, kembili and kumbili java. It is also known as hausa potato, Sudan-potato, country potato, fra-fra potato, fra-fra-salanga, ratala, pomme de terre du Soudan, hausakartoffel, innala, saluga, tumuku and fabirama. 

Nutritive status
The nutritive status of this crop compares favourably with many of the major tuber crops.  Coleus tuber, with its characteristic  flavour has a special preference among consumers. Compared to other tuber crops, it fetches premium price in the market, although it is known as poor man’s potato. The tubers are used for the preparation of various delicious side dishes. Reliable data on area and production of this crop are not available. Despite the high market price and consumer preference, it is not available throughout the year.

The term arrowroot is commonly applied to many starch producing plants belonging to different species whose economic part is the rhizome, eaten fresh or made into flour. The term applies both to flour and the plant. All the plants of the arrowroot group have underground rhizomes or tubers from which arise reed like erect stems. The word ‘arrowroot’ is derived from the pointed shape of the rhizome or its known ability to cure arrow injuries. The word itself is derived from the carib word araruta meaning mealy roots. The arawak, a people native to the Caribbean islands, considered arrowroot a dietary staple. They called it aru-aru meaning meal of meals.

Tripura is situated between 22º 56’to 240 32’ N latitude and 91010’ to 92021’E longitude with tropic of cancer passing through it. The total geographical area of state is about 10,491 km2 of which 57.98 % area is under forest cover.  Agriculture is an important sector in the state, which contributes 26 % of the State GDP of which the major contribution is from horticultural crops like fruits (pineapple, litchi and oranges), vegetables (potato TPS), plantation crops (cashew nut, coconut, rubber and tea) and spices (ginger, turmeric and black pepper). More than 75 % of the population either directly or indirectly depends on agriculture. The small and marginal farmers constitute about 90 % of total farming community and the average size of land holding is 0.97 ha (1990-91) in comparison to 1.25 ha (1976-77), which is the lowest among the seven other North Eastern states.

Introduction

Plantation crops are high value commercial crops which are broadly classified as estate crops consisting of crops like tea, coffee and rubber and small holders plantation crops like coconut, cashew, arecanut, cocoa etc. Spices especially black pepper, cardamom, vanilla, tree spices like clove, nutmeg, cinnamon and allspice are generally grown as mixed crops in perennial cropping systems. In India, plantation crops including spices are grown in an area of three million hectares and generate an annual income of more than Rs, 5,53,630 million. They are valued for multifarious uses to meet the human needs such as food, oil, industrial raw materials, beverages and confectionary items. Pests and diseases are the major limiting factors in increasing the productivity of these crops. Among the pests, nematodes have got a major role in devastating the pepper plantations by the involvement in slow wilt disease, nematode diseases of cardamom nurseries, root-knot nematode infestation in ginger, turmeric, clove, nutmeg, allspice, lesion nematode infestation in tea, coffee, etc.

Introduction

Biological control of plant pathogens is currently accepted as a key practice in sustainable agriculture. Plant parasitic nematodes and mycorrhizal fungi are commonly found inhabiting the same soil and colonizing roots of their host plants. These two groups of microorganisms exert a characteristics, but opposite effect on plant health. The potential role of mycorrhizal fungi as biocontrol agent for the control of nematode plant diseases has recently received considerable attention. The literature on the various aspects of VAM research such as interaction of VAM- mycorrhizal fungi with nematode pathogens (Sikora, 1995, Pinochet et al. 1996), biotechnology and future of VAM commercialization (Wood and Cumming, 1992) and trends in mycorrhizal research (Sahay et al. 1998) has been reviewed. The damage due to nematodes diseases is generally decreased in mycorrhizal fungi has shown an antagonistic influence on the population of plant parasitic nematodes (Nagesh et al. 1999, Kantharaju et al.

Protected Cultivation

Protected cultivation (PC) may be defined as the “modification of the natural environment to achieve optimum plant growth” (Singh, 2005). Modifications can be made to both the aerial and root environments to increase crop yields, extend the growing season and permit plant growth during periods of the year not commonly used to grow open field crops. PC may also indicate comprehensive systems of ‘Controlled Environmental Agriculture’ in which all the aspects of natural environment are modified for maximum plant growth and economic return.

Introduction

Nematodes are cosmopolitan and ubiquitous in occurrence. These have been reported in all kinds of ecological niche. Accordingly, different kinds of nematode fauna had evolved with distinct morphological features and physiological variability. However, development and perception keep changing with the ambient environment. Agriculture has progressed with leap and bounce as human being has managed this to its maximum utility. The fast changes in agriculture definitely influenced the ecological niche and affected the flora and fauna. Consequently, specific and unspecific kind of relation evolved between host and parasite. With the thumb rule of ecological balance or homeostasis. In the dynamic Mother Nature, multispecies heterogeneous complex is sustained and nature do not perpetuate homogeneity.

Introduction

Banana is the forth ranked agricultural crop in the world and first among fruits. A large number of pests and diseases threaten banana production. The major constraints in production are diseases and pests transmitted through the conventional planting materials. Although the average yield for bananas worldwide is over 40 t per hectare, production in India averages only 20 t per hectare. The nematode parasites are among the most important pests on commercial and subsistence banana production and their control remains difficult, as the nematodes are involved in the destruction of primary roots that disrupt the anchorage system resulting in toppling or uprooting of plants. The most widespread and important are burrowing nematode, Radopholus similes, some species of root lesion nematode, Pratylenchus coffeae and P. goodeyi, species of root knot nematode, Meloidogyne incognita and M. javanica; the spiral nematode, Helicotylenchus multicinctus, H. mucronatus and semi endo-parasitic nematode Rotytlenchus reniformis.

Introduction

Seed spices have prominent place in India’s national economy because of their very high domestic consumption and growing demand for export. This group of spices, being consisting of mostly annual crops, is grown extensively in rotation with food and cash crops and also as inter crops under rain fed as well as irrigated conditions.

There are about 20 seed spice crops grown in India. Out of which nine are important in terms of production and export. The most important ones are coriander, cumin, fennel and fenugreek (major seed spices) and ajowain, aniseed, black cumin, celery and dill (minor seed spice crops). Although these crops are grown all over India but Haryana, Rajasthan, Madhya Pradesh, Uttar Pradesh, Orissa, Tamil Nadu and Andhra Pradesh are the main seed spice growing states.

Introduction

Rice (Oryza sativa L.), one of the most important cereal crops of India, occupies 23.3 per cent of total cropped area of the country. Rice contributes 43 per cent of total food grain production and 46 per cent of total cereal production. It continues to play a vital role in the nation’s food grain supply. It is also a staple food of nearly half of the world population. Rice is primarily a high caloric food having protein content (6-17%) with high biological value and a low amount of fat (2-2.5%). B-group vitamins content in rice grains are at par with wheat, however, calcium content in rice is generally low. It ranks third after wheat and maize in terms of worldwide production. Asia accounts for 90 and 92% of the world’s rice area and production, respectively. Thus, rice production, consumption and trade are concentrated in Asia. Among the rice growing countries in the world, India has the largest areas under rice crop and ranks second in production next to China.

Introduction

Maize (Zea mays Linn) is the most widely distributed crop of the world. It adapts easily to a wide range of production environments and is grown in tropical, subtropical and temperate regions of the world. It holds a unique position in world agriculture ranking third after rice and wheat in terms of area as well as production. In India too, it is the third most important cereal crop and is cultivated in 8. 17 m ha (2007-08) area. It contributes nearly 8% to the national food basket and more than Rs 100 billion to agricultural gross domestic products with an annual production of 19. 73 million tons. It is used as a source of human food (24%) animal feed (11%), poultry feed (52%), starch (11%), brewery and seed (1% each). In India it is largely grown in Northern states where it serves as an important staple food for an economically vulnerable population of submountainarean and hilly regions.

Introduction

Plant paprasitic nematodes are one of the limiting factors in the production of horticultural crops in the country. The visible symptoms of nematode attack are: Reduced individual plant growth, varying degrees of chlorosis, wilting of the foliage and sometimes death of the plants.

The roots, damaged by nematodes are not efficient in the utilization of available moisture and nutrients in soil resulting in reduced functional metabolism. Nematode infested roots are easily infected by various pathogenic fungi and bacteria and aggrevate root damage. These deleterious effects on plant growth result in reduced yield and poor quality of crops as in citrus, banana, grapevine, pineapple, papaya and vegetable crops. Decline or death of highly prised ornamentals and turf is often the result of nematode infestation.

Introduction

India has the distinction of being the largest producer of pulses in the world. Among the important pulse crops cultivated in the country are: chickpea, pigeonpea, lentil, mungbean, urdbean, fieldpea, rajmash and lathyrus. The pulse crops occupied an area of 22.85 million ha with a total production of 13.07 million tones and average productivity of 572 kg/ha. Being a high protein grain, pulses have special status in the diet, particularly for vegetarian population. Apart from being a good source of protein, they are also good source of energy, essential amino acids and vitamins in the daily diets of the people, especially of low-income group. Pulses have importance in sustainable agriculture by way of fixing atmospheric nitrogen in the soil.But with intensification of agriculture and introduction of irrigation and other facilities the area and production under pulses is declining so much so that per caput availability of pulses has declined from 69 g day-1 to about  36 g day^-1.

Preamble

In India, agriculture plays an important role as it accounts for about 18% of the GDP and supports nearly 58% of the total working population for employment. Food grain production increased significantly from a low level of 50 million Tons during 1950-51 to a record of 230.7 million Tons in 2007-08. The demand for food is growing rapidly due to increasing population and rising income levels, hence we need to produce about 320 million Tons of foodgrains by the year 2025. It implies more pressure on our exhisting land, soil and water resources which are already in short supply, degraded, fragile and this similar situation is being faced by mainly developing countries today. Plant parasitic nematodes are of great economic significance. Since most of them live in the soil hence represent one of the most difficult pest problems in terms of identification, demonstration and management.

Introduction

The cereal cyst nematode, (Heterodera avenae Woll.) a causal organism of ‘molya’ disease in wheat and barley, since after its first report (by Wollenweber, 1924, Vasudeva, 1958 and Prasad et al., 1959), it has been timely reviewed about its spread and losses caused in the various parts of wheat and barley growing areas of the world. It has been reported to occur in Australia, Canada, Israel, South Africa, Japan, in most of the European countries, North America, India, Morocco, Tunisia, Pakistan, Libya, Turkey and Australia (Prasad et al., 1959, Smiley et al., 1994, Rumpen horst et al.,1996, Krall et al., 1999, Nicol, 2002 and Rao et al., 2002). Its economic importance has been assessed by mapping the yield losses caused in cereals i.e. ranged from 15-20% in Pakistan, 40-92% in Sauthi Arabia, 23-50% in Australia (Nicol, 2002) and 40-50% in India (Mathur 1969, Mathur et al., 1980, Handa et al., 1985, Mathur, et al., 1987).

The highly specialized organs that receive physical and chemical stimuli from the environment and various body parts, and transform them into stimuli are called sense organs or sensory receptors. These organs are closely associated with nervous system. The physical stimuli such as change of heat, light intensity and quality, acoustical stimuli and chemical stimuli like hear, taste, smell, touch, lateral line etc are received by the sense organs such as ear, eye, nose and others. These are more prominent sense organs. Less obvious ones in fishes are sensory crypts and papillae, ampullae of Lorenzini and Savi.

The crustaceans have various sense organs whose action are mediated through the nervous system. Crustacean antennae are important sites for the reception of environmental information, mainly chemical, and aesthetases, the olfactory hairs on the first pair, are usually well developed. The aesthetases help not only in locating food but also in recognizing other individuals and their sexual state.  The frequent grooming of the antennae by many decapods prevents fouling of the receptor sites (Bauer, 1971).

Most of the aquatic organisms spend much of their lives and energies for reproduction. The young ones mature, develop sperms or eggs, spawn, and then recover to repeat the breeding cycle that continues till their death. In a majority of fish species males and females are separate individuals, fertilization is external and large number of eggs are produced (on an annual basis, its fecundity) which develop, hatch and mostly grow without parental care. The sperm and eggs are usually produced in such quantities that they represent a large expenditure of energy. The spawning process may be preceded by migrations or nest building, and followed by care of the young. Thus the success of any fish is ultimately determined by the ability of its members to reproduce successfully in a fluctuating environment and thereby to maintain viable populations.  As each fish species occurs under an unique set of ecological conditions, it has an unique reproductive strategy with varied anatomical, physiological, behavioral and bioenergetics adaptations. Unlike the finfishes, in shellfishes sexes are separate. The shellfishes use various signals to attract the opposite sex.

Excretion is the process of elimination of metabolic wastes that include toxic nitrogenous end products of the protein metabolism and the gas such as carbon dioxide (CO₂). These nitrogenous wastes are excreted through urine. Fecal matter is not included in the excretory products as it is simply the undigested food materials, and are not metabolic end products. The membranes of aquatic animals, that is permeable to gases, pass water and solutes between environment and body. Most aquatic animals maintain in their bodies a reasonably constant proportion of water and solutes. When it is different from the surrounding water, it requires some mechanism for regulation, which is known as osmoregulation. Most invertebrates in the sea have nearly the same salt concentration (isosmotic or isotonic) as the environment. Sharks and rays (elasmobranches) tend to have a slightly higher concentration of salts and urea (excretory end products) than seawater but the body fluids of most teleosts (bony fishes) have much lower salt concentration than seawater. Freshwater fishes, which live in a medium of lower salt concentration (hyposmotic or hypotonic), have the threat of hydration, so they have special mechanisms to get rid of excess body water. Marine fishes that live in an environment of high salt concentration (hyperosmotic or hypertonic) have the regulatory mechanisms by which excessive loss of water from the body is prevented and body osmolarity (proper osmotic concentration) is maintained by retaining less toxic nitrogenous excretory products. Marine fishes, which lose water osmotically across the gills and must get rid of salt, tend to drink large volume of seawater and produce very small quantities of urine (Fig-6.1).

The respiration of animals includes the exchange of gases either at the surface of the body or through the internal processes involving circulatory system. The gases that are exchanged are oxygen (O₂), carbon dioxide (CO₂) and the inert gas like nitrogen. When the organism respires, the O₂ that is taken up from the external environment is transported by the vascular system to individual cells within the tissues. At the same time this system picks up CO₂, an end product of cellular metabolism, and releases it to the environment. Thus respiration is a term applicable either to a whole organism or one of its cells. The mechanical process, by which respiration is achieved, is called ventilation.  This ventilation rate of aquatic organisms is controlled directly by the concentration of dissolve oxygen (DO₂) in water.

Respiration in aquatic medium is produced by a water current passing in a single direction. The area of respiratory surface is thus an important limiting factor in the movement and growth of the animal. For aquatic animals, if the water is at all deficient in O₂, the rate of breathing is naturally accelerated, and the animal appears to respire hurriedly. Other factors, which lead to an increased rate of respiration, are the stresses.

Various activities of the body in different external environmental conditions are co-ordinated by the appropriate message from the neurons due to the stimuli from the environment. These messages pass in the form of impulses through the co-ordinated links between a number of neurons or nerve cells. The constant passage of messages require a very little energy but high level of O₂ .There is interaction between the nervous and endocrine system with the areas of interchange among the two systems. Some neurons show the action of both the systems and thus termed as neurosecretory or neuro-endocrine. Fishes have a well-developed nervous system. Broadly the nervous system can be divided into central nervous system (CNS) and peripheral nervous system (PNS).The brain and spinal cord are the parts of the CNS. The motor and sensory nerves link the receptor and effector organs. All nerve tissues other than brain and spinal cord are grouped under PNS. Peripheral nervous system consists of nerves, ganglia and receptors. The nerves carry sensory information from special receptor organs like eyes, internal ear etc. to the integrating centers of the brain and spinal cord. The PNS also carries information via different nerve cells from the integrating centers of the brain and spinal cord. This coded information is carried to the various organs and body systems, such as the skeletal muscle system for appropriate action in response to the original external and internal stimulus. The PNS can be divided into somatic and visceral. The term visceral is sometimes used in referring to the autonomic or involuntary nervous system (ANS), controlling visceral functions. The ANS helps to co-ordinate the activities of many glands and organs, and it is closely connected to the integrating centers of the brain.

Embryologically, the circulatory system is the first organ system to develop in the living animals. The form and function of this system vary considerably among the animals and are shaped by a variety of environmental factors i.e. phenotypic plasticity. Oxygen (O₂) acquisition and carbon dioxide (CO2) elimination occur simultaneously at the gill site of fish and shrimp. The gases are transported around the body by the circulation of the blood.

3.1. Circulatory System of Fishes

In fishes, heart is simply a muscular enlargement and modification of a part of the main blood vessels, lying between the hepatic capillaries and the gills. Fishes have a closed circulatory system with a heart that pumps blood in a single loop throughout the body. From the heart, blood goes to the gill capillary bed. Then via the systemic capillaries it returns back to the heart. Usually the gills account for approximately 30% of the total resistance to blood flow, the rest being in the visceral and somatic vasculature. Tuna requires more O₂ and the gill area is large with gill resistance up to 57%.

The knowledge of food, feeding habit, anatomical adaptations and the physiology of digestion of the candidate aquaculture species is highly essential to develop cost-effective artificial feed for successful culture practices. The digestion of poikilothermic aquatic fishes and shellfishes is influenced by many factors, and is different from the digestion of terrestrial animals.

2.1.    Anatomy and Physiology of Fish Digestive System
2.1.1.  Feeding Behavior of Fishes

Based on the feeding habit, the fishes are generally classified as herbivores, omnivores, carnivores and detritivores. Within these categories, the fishes further categorized as euryphagous, having a mixed diet, stenophagous, consuming a limited combination of food types and monophagous, accepting only one type of food. A majority of fishes are euryphagous carnivores, and their feeding mode and food types are associated with the body form and digestive system. Fish generally change their feeding habits depending upon the availability of food. Fishes may be classified as predators, grazers, strainers etc. Plankton is a collective term for variety of marine and freshwater plant or organisms that drift on or near the surface of the water. Most fishes eat the material that is smaller than them. The smallest fishes eat these planktons, which act as their main food and all smaller fishes are the food of the bigger fishes. Largest shark feed on plankton by straining these tiny marine plants and animals from the water. The zoo-planktons, comprise protozoa, small crustaceans, jelly fish, and mollusks, together with the eggs and larvae of many species of marine and fresh water.

Aquaculture is the culture of aquatic organisms per unit water area per unit time for maximum profit. The economically important finfishes and shellfishes, whose body physiology is adjustable to varied environmental conditions, are considered as aquaculture candidate species. So, an overall knowledge on the physiology of such species is required to improve the culture practices.

1.1. Finfish

A fish may be defined as a vertebrate, adapted for a purely aquatic life, propelling and balancing itself by means of fins, and obtaining oxygen  (O2) from the water for survival and life processes. As the fishes have fins, they are also known as finfishes. Fish describes a life from rather than a taxonomic group. They share certain features with other vertebrates. These are gill slits, a notochord, a dorsal hollow nerve cord and tail. In number of individuals, and may be also in number of species, fishes are presently superior to other vertebrates, including mammals. There are 20,000 different species of fishes. Fishes form largest group of vertebrates, Pisces. The various types of fishes differ so much in shape, color and size that it is difficult to believe they all belong to the same group of animals. Fish in general are cold-blooded and adjusted either to freshwater, brackishwater or marine environment.

Anar butterfly, Deudorix isocrates (Fab.)

The pest has been found boring into fruits of pomegranate. Besides it may attack guava, aonla, apple, ber, citrus, litchi, loquat, sapota, etc., pomegranate is the most preferred host for this pest. It may destroy up to 50 percent fruits. The female lays eggs singly on calyx of flowers or small fruits. On hatching, the caterpillars bore inside the developing fruits and are usually found feeding on pulp and seeds just below the rind; subsequently bacteria and fungi causing fruit rot also attack the infested fruits. The conspicuous symptoms of damage are offensive smell and excreta of caterpillars coming out of the entry holes, the excreta is found stuck around the holes. The affected fruits ultimately fall down and are of no use; even if the fruits be picked before falling down, these fruits have no market value.