eChapters

Important insect-pests of vegetable crops

1. Aphids: (Myzus persicae)

The aphids damage the crop by sucking the cell sap from the leaves as stems. The affected leaves in severe cases curl-up and rolled. The plant may be stunted, wither and die. There are three different species of aphids. They are greenish or black in colour.

Lawn

Lawn is a natural green carpet, and it is important feature of a landscape and a garden without a lawn is not considered complete. Lawn is an area of land closed mowed grasses it is primarily developed for aesthetic and recreational purpose. A lawn is an integral part of a garden and landscape besides aesthetic and recreational purpose and several other purposes. Lawn provides a place for taking rest after tiring of the day, holding parties, social functions, passive and active recreation. Distinguishing characteristic of turf grasses is the ability to with stand close mowing and still providing a functional dense healthy ground cover. Lawn is also called as heart of garden. J.B. Olcoth designed first experiment in lawn grass at Monchester in USA in the 19th century. Festuca and Agrostis species were used to make turf (Lawn) during 1880 in U.K. In the early 19th century lawn become wild spread out side of parks golf course. Now a day in many metro cities of India lawn has become a cultural of the passion of many homes.

5.1 Introduction

The different qualitative chemical tests can be performed for establishing profile of given extract for its chemical composition. The following tests may be performed on extracts to detect various phytoconstituents present in them.

5.2 Detection of Alkaloids (Evans, 1997)

Solvent free extract, 50 mg is stirred with few mL of dilute hydrochloric acid and filtered. The filtrate is tested carefully with various alkaloidal reagents as follows:

The increasing awareness of the deleterious effects of indiscriminate use of artificial inputs in agriculture such as chemical fertilizers and pesticides hasled to the adoption of organic farming as an alternative method for conventional farming. Farmers are adopting organic farming due to the advantages like,

• It is self-sustaining and socially and ecologically superior over the conventional farming.
• It makes use of cost effective management practices involving the use of farm inputs produced within the farm.
• It is less expensive.
• It is environment friendly as there is no pollution of soil and water.
• It enriches the soil and the local ecology.
• The produce is free of contamination from chemical residues has better taste, flavour and nutritional value.
• Seeds have more vitality and are good for successive generations.
• Growing markets for safe food

The concept of Centers of Origin given by Russian scientist N.I. Vavilov (1935) is based on his studies of vast collection of plants at the Institute of Plant Industry, Leningrad. According to him, crop plants evolved from wild species in the areas showing great diversity and termed them as primary Centers of Origin; but in some areas, certain crop species show considerable diversity of forms although they did not originate their, such areas are known as secondary Centers of Origin of these species. He identified 8 primary centers (Chinese, Indian, Inner Asiatic, Asia Minor, Mediterranean, Abyssinian, South Mexico, Central America and South America Andes Center) and three sub-centers (Indo-Malayan, Chilean and Brazilian-Paraguayan sub-center) of origin for crop plants. Basilevskaya (1960) first investigated the geographical origin of garden plants. Coats (1968) first stressed out the ornamental herbs whereas Hui-Lin-Li (1974) wrote about the introduction of woody plants. According to Tay (2007) survey of thirty common flowers and their related species show a similar pattern of concentrated occurrence of species in certain geographic regions.

Exploration and exploitation of gene centers need to be proceed with the systematic cooperation of taxonomists, geneticists and plant pathologists. The 17 centers of origin identified for different flower and ornamental crops are given (Table 2.1)

These centers coincide to a significant extent with the regions of the Conservation International’s Biodiversity Hot spots in the world. No one single country is self sufficient in all the germplasm of flowers. The centers of origin of ancient flowers from China and Turkey coincide with the Vavilov’s food crop centers of origin. Domestication of food crops might also lead to the domestication of those flowers. Flowers were part of crop weed complex from the beginning and those with beautiful flowers would have been selected for domestication.

Eswaran (2007) made genetic analysis of six parents and their 30 hybrids of Okra with the method of analysis proposed by Hayman (1954b). He estimated the various genetic parameters viz., _D?, _F?, H?₁, H?² and Ê as well as the various genetic ratio. The results are presented in Tables 69 and 70.

The estimates of _D? were significant for seven out of ten characters studied. This indicated that the component of variation due to additive genetic variance was important for days to seedling emergence, number of first fruiting node, height of first fruiting node, plant height, days to first picking, number of fruits per plant and fruit weight. These characters could be improved by resorting to simple selection. The estimates of H? ₁and H? ₂were positive and significant for almost all the characters studied. It indicated that there were unequal frequency of alleles i.e., u ¹ v at all the loci, in this context, ‘u’ refers to the frequency of alleles which increase the mean expression of the character and are situated at loci which exhibited dominance. On the other hand, ‘v’ corresponds to the frequency of alleles at loci that decreases the expression of the character. Further proof for the unequal distribution of the alleles over loci was obtained

Introduction

‘Protected cultivation’ is a method of cultivation of plants or crops in artificial environment (Polyhouse/ Greenhouse/Glasshouse) to protect the plants or crops from the natural calamities viz. wind, hailstorm, excessive radiation, temperature extremes, insect-pests and diseases. For matching ever growing needs of human population in the country, it has become imperative to provide the not just cereals but also fruits, vegetables, flowers and other horticultural products to fulfill their requirements. In the present scenario of perpetual demand of horticultural produce in order to increase their production round the year and shrinking landholdings drastically, protected cultivation is the best alternative and drugery- less approach for using land and other resources more effeciently.Protected cultivation comprised of selection of crop and media, climate control,marketing, post harvest technology, plant protection and irrigation/ fertigation.

In India, states like Karnataka, Andra Pradesh, Maharashtra and Tamil Nadu are the best suited for protected cultivation of horticultural crops due to their pleasent climatic conditions. Apart from these states, Himachal Pradesh, Uttar Pradesh, Jammu and Kashmir, West Bengal, Delhi and Jharkhand are also fore runners in adopting protected cultivation. Protected cultivation is a key for sustainable production in the country due to its various ecological regions viz., Western Himalayan region, North eastern Himalayas, Eastern Plateau hill regions, Central Plateau hill regions, Western Plateau hill regions, Southern Plateau hill zone, East coast hill zone, West coast hill regions and Gujarat hill regions (Gupta et al., 2003). Control of light through polycover has become a significant part of horticulture technology because quality, intensity and duration of light is involved in many physiological processes of the plants. A plastic film or fibre glass covering over a green house acts like selective radiation filter which allows solar radiation to pass through but traps radiation emitted by the plants inside the greenhouse which is known as ‘Greenhouse effect’. Carbon dioxide released by the plants at night also trapped, this raises the level of CO₂ there by enhances the photosynthetic activity (Ahmed, 1996).

Bael [Aegle marmelos (L) Correa.], a native fruit of religious importance, is well known to the Indian people for its nutritional and medicinal values. Leaves are used as sacred offering to ‘Lord Shiva’. All parts of plant viz., leaves, roots, bark, fruits, seeds etc. are used in preparation of various Ayurvedic medicines. Bael fruit is rich in protein, fat, minerals (Ca and Fe) and vitamins (riboflavin, β carotene and Vitamin C). Fruits are used to improve the digestive system and to cure stomach diseases. Fruits can be processed into various beverages and preserves (Jauhari and Singh, 1971). In spite of its Indian origin and high medicinal and nutritional values, well organized orcharding of bael is not commonly seen in the country. It is mainly found in wild and semi-wild condition throughout the India. Besides, it is also grown in the homestead gardens, backyards, religious places and farmer’s fields (Misra and Uniyal, 2013).

Tomato is one of the most popular and widely grown nutritious vegetable in the world. Tomato (Lycopersicum esculentum Linnacus Karst.) belonging to the family Solanaceae is one of the most nutritious and remunerative vegetable crop. It is the world’s important vegetable next to potato. The crop is cultivated throughout the year. In Northern plains, the crop is cultivated during autumn, spring and summer. In South India, the crop is grown in June – July, October – November and January – February. The optimum season for seed production in southern India is October – December. Nursery raised in late October and transplanted in the first week of December will produce a good seed crop.

The brinjal, eggplant or aubergine (French name) has originated in the Indian sub-continent and China (Thomson and Kelly, 1957, Purewall, 1957 and Martin and Rhodes, 1979). Brinjal is an important vegetable crop of the Far East, Bangladesh, India, China and the Philippines. Brinjal belongs to the family Solanaceae and is known under the botanical name Solanum melongena L. (2n = 24). There are 3 main botanical varieties under the species melongena(Chowdhury, 1976). The round or egg-shaped cultivars are grouped under var. esculenturn, the long slender types are included under var. serpentintumand the dwarf brinjal plants are put under var. depressum.

Chilli or Pepper (Capsicum Sps.) originated in South America and spread into the New World tropics before subsequent introduction to Asia and Africa. Chillies are now widely grown throughout the tropics, sub-tropics and warmer temperature region of the world. The genus Capsicum is a member of the family Solanaceae.

Lablab purpureus usually knowna s Dolichus bean, Hyacinth bean or Field bean belonging to the family fabaceae, one of the most ancient crops among cultivated plants. It is a bushy, semi-erect, perennial herb, showing no tendency to climb. It is mainly cultivated either as a pure crop or mixed with finger millet, groundnut, castor, corn, bajra or sorghum in Asia and Africa. It is a multipurpose crop grown for pulse, vegetable and forage. The crop is grown for its green pods, while dry seeds are used in various vegetable food preparations.

Season:Seed is very sensitive to weather. A grain crop can be sold for a lower price even if it damaged by rain. But a seed crop, if affected will lead to low seed quality. Hence selecting the right season is necessary. Generally, the seed should mature in cool dry climate. Seasons should be selected with this idea in mind. In Tamil Nadu the best seed crops are grown during March--April and September - October as the seeds mature during the cool months of January - February.

Botany :The cabbage plant, Brassica oleracea, is an herbaceous annual or biennial vegetable in the family Cruciferae grown for its edible head. The head of the cabbage is round and forms on a short thick stem. The leaves are thick and alternating with wavy or lobed edges and the roots are are fibrous and shallow. The plant produces large yellow flowers. The densely leaved heads can range in size from 0.5 to 3.6 kg (1-8 lb) depending on variety. The plant is usually grown as an annual.

Origin

Beet root originated from Beta vulgaris L. ssp. maritima by hybridization with B. patula. Crop has site of origin probably in Europe. Earlier types were with long roots like that of carrot. Beet root, sugar beet and palak belong to species B. vulgaris and are cross compatible.

Botany

Beet root is a biennial, producing a fleshy elongated hypocotyls and a rosette of leaves in first year and flowers in second year. Upper portion of fleshy root develops from hypocotyls and basal part from tap root. Concentric rings seen in cross section of root are as a result of alternate formation of vascular tissues and storage parenchyma tissues. Root skin colour varies from orange red to dark purple red. Colour of beet root is due to presence of red violet pigments of â cyanins and a yellow pigment, â xanthin. It has extensive tap root system and tap root grows as deep as 3m. Rosette leaves develop in a close sp

The great Indian epic ‘Ramayana’ says that ‘Lord Rama’ has tried to cross over the Bay of Bengal so as to reach Sri Lanka from India from three points along the southeastern fringe of the Indian coast. Firstly, he is said to have tried to cross from Vedaranniyam which is mythologically called as ‘Kodiyakkarai’ Secondly from Manamelkudi and finally crossed over to Sri Lanka from Rameswaram Island (Fig.1), as the former two coastal locations were widely separated from Sri Lanka by Bay of Bengal and the Rameswaram Island was nearer to Sri Lanka during that period. But, the recently acquired satellite data shows the huge accretion of sediments and rapid land building activity off Vedaranniyam coast (Fig. 2 and 3). The geomorphic interpretations carried out using IRS 1A imagery and 14^C archaeological dating of such geomorphic features have shown that such ongoing sediment accretion phenomena off vedaranniyam nose might in future connect the Vedaranniyam part of Indian Peninsula with Jaffna Peninsula of Sri Lanka if the sediment accumulation continues unabated. The sediment accretion in this area, therefore, requires detailed studies particularly in the context of the coastal ecosystem (Fig. 1).

ABSTRACT

Studies on the behaviour of animals are of utmost importance in the conservation of species. Ecology of the communities and individual species has to be examined in terms of different activities to understand the requirements of the species. Foraging and breeding are the major activities while resting and flight maintenance are also essential, although the time spent might vary in different species or situations.

Bird community studies conducted along with my students in different habitats in the Western Ghats since 1995 showed how the species are associated with each other and the impact of habitat changes on them. Endemic and threatened birds of the Western Ghats were specific about selection of habitat and food in different seasons. Identification of such critical habitats is crucial for conservation and management.

The studies on the bird community and drongos at Thekkady, Periyar Tiger Reserve conducted by me during 1979 to 1982, examined the association of drongos with other species in the area, especially while foraging. They fed mostly in mixed foraging flocks which is beneficial to all the participants. The strategy adopted by them for ecological isolation to reduce competition was by selecting different strata and substrate of the vegetation, varying sizes of insects, and methods of feeding.

In the case of wetland birds also habitat selection is a major behaviour limiting their numbers. For the threatened birds such as the Siberian Crane and the Andaman Teal, habitat quality and food availability were critical. Habitat degradation with over abundance of grass and reduction in sedges resulted in spending long duration for feeding and less returns.

Breeding behaviour of birds is interesting because of their strategies such as when to nest and where to nest. Studies on the seasonality have shown the importance of climatic factors. Many of our land birds nest during summer. Nest-site is also crucial as selection of the site with suitable macro and micro-habitats determine the success of the brood. The habitat patches for the individual pairs or groups of breeding birds which are defended against intruders are termed as territories which play a vital role in the distribution and density of birds. Thus the strategies adopted by species are dependent on the environment and species specific constraints affecting the survival of the species.

Introduction

The common mycorrhizal association in most of the plants is the arbuscular type occurring in the majority of agricultural and horticultural crops. Arbuscular mycorrhizae (AM) are formed by non-septate Zygomycetous fungi belonging to the genera Glomus, Gigaspora, Acaulospora, Sclerocystis, Entrophospora, Scutellospora, Archaeospora and Paraglomus in the order Glomales. These fungi are obligate symbionts and have not been cultured on nutrient media. These endophytes are not host specific although evidence is growing that certain endophytes may form preferential association with certain host plants. Several investigations indicted that even in unsterile soils plants do respond to inoculation with efficient strains of arbuscular mycorrhizae. Numerous experiments have been conducted in different parts of the world confirming this growth improvement. The increased growth of mycorrhizal plants is favoured in soils with low to moderate fertility. More specifically, soils favouring mycorrhizal growth stimulation usually have one or more essential nutrients, especially phosphorus, in limiting concentrations.

The mechanism of improved plant growth caused by mycorrhizal inoculation has been investigated by many workers. Greater soil exploration by mycorrhizal roots as means of increasing phosphate uptake is well established. They also improved the uptake other diffusion-limited elements like Zn, Cu, etc. The other beneficial effects are their role in the biological control of root pathogens, biological nitrogen fixation, hormone production and greater ability to withstand water stress (Bagyaraj, 1984).

ABSTRACT

Techniques could be standardized for the induction, initiation, maturation and germination of somatic embryoids from the nucellar tissue isolated from 30-45 day old fruits of mono embryonic mango variety Neelum and poly embryonic variety Vellari Manga. The treatment half strength Murashige and Skoog basal medium containing 2,4-D 5.0 mgl^-1, GA3 5.0 mgl^-1, glutamine 400 mgl^-1, coconut water 200 mll^-1, activated charcoal 500 mgl^-1, sucrose 60 gl^-1and agar gl^-1was found to be the best in induction of embryogenic callus. The treatment 2,4-D 4.0 mgl^-1 + BA 1.0 mgl^-1+ GA3 5.0 mgl^-1in half strength MS basal medium supplemented with glutamine 400 mgl^-1, casein hydrolysate 500 mgl^-1, sucrose 60.0 gl^-1, coconut water 200 mll^-1and agar 6.0 gl^-1was the best in initiating somatic embryos from the induced nucellus of the three varieties. In the variety Neelum BA (8.0 and 16.0 mgl^-1) and kinetin (8.0 to 32.0 mgl^-1) were as effective as 2,4-D in inducing somatic embryogenesis. Polyembryonic variety Vellari Manga showed better response to induction treatments than the mono embryonic varieties. B5 major salts with MS minor salts in combination with 40 gl^-1sucrose, 10 gl^-1PVP, 200 mll^-1coconut water, 5.0 mgl^-1 ABA, 100 mgl^-1 casein hydrolysate and 6.0 gl^-1agar were the best suited for the maturation of the somatic embryos. The positive influence of cobalt chloride, casein hydrolysate and coconut water on the germination of embryoids of both mono and poly embryonic mango varieties could be well established. A basal medium consisting of B5 major salts and MS minor salts supported the highest percentage of germination of somatic embryoids in Neelum and Vellari Manga. However, abnormalities in germination were observed in most of the cases. Excellent germination of somatic embryos was observed in a liquid medium consisting of half strength B5 macro salts and full strength MS micro salts and supplemented with GA3 1.0 mgl^-1+ glutamine 400 mgl^-1 + sucrose 30gl^-1.

ABSTRACT

The totipotency of triploid endosperm tissue is exploited in many vegetatively propagated crops. Hevea brasiliensis, the most important commercial source of natural rubber, is a highly heterozygous perennial tree with a long breeding cycle. Conventional method of triploid production by crossing a diploid with an artificially induced tetraploid is a lengthy and laborious process. Hence in vitro regeneration of plants from endosperm tissue provides an easy and direct approach for the production of large number of triploids. Hevea fruits at different developmental stages were collected and sterilized using 0.1% HgCl₂ for 15 minutes. Seeds were dissected out and the embryos and inner integuments were removed. Endosperm is cut into small pieces and cultured over MS medium supplemented with various levels of sucrose, phytagel and growth regulators viz BA, Kin thidiazuron, 2,4-D, IBA, NAA, zeatin & GA. Organic supplements viz. yeast extract, casein hydrolysate, coconut milk and banana powder were used for callus and embryo induction. Optimum callus induction was obtained in media supplemented with 2,4-D (2.0 mg ^-1) and Kinetin (3.0 mg^-1). On further subculture of the primary calli to medium containing zeatin (1.0 mg ^-1), embryogenic calli could be obtained. Embryos were induced in MS medium supplemented with ABA (0.3 mg ^-1) , Kin (0.3 mg ^-1) and GA (0.5 mg ^-1). Maturation, germination and bipolar differentiation of the embryos were achieved in MS medium devoid of growth regulators. Root tips from the germinating embryos were subjected to cytological analysis and found to be triploids (3n=54). Regeneration from Hevea endosperm is being reported for the first time. The results indicates that like many other crops, Hevea endosperm responds well under in vitro conditions and endosperm culture could be utilized as a viable technique for triploid plant production.

ABSTRACT

Immature seeds of Garcinia indica were excised from the green fruits and cultured on Woody Plant Medium (WPM) with a combination of auxins and cytokinins. Somatic embryos were obtained on the media supplemented with BAP (0.5-5.0 mg/l) alone or in combination with NAA 90.5 mg/l) with 80 per cent frequency within a period of 2-3 weeks. Subculture of primary embryos on maturation medium containing BAP (3.0 mg/l) supplemented with IAA (0.5-1.0 mg/l) and / or Kinetin (1.0 mg/l) gave rise to clusters of secondary somatic embryos. In the subsequent subculture on hormone free half strength WPM the embryo clusters germinated with repetitive secondary embryogenesis. About 70 per cent somatic embryos germinated into complete plantlets, which were successfully transferred to the green house conditions.

ABSTRACT

The investigation was carried out to develop protocol for micropropagation of acid lime (Citrus aurantifolia S) var. Sai-Sharbati. Shoot tip and nodal segment explants were obtained from axenically grown seedlings having 21 to 30 days age. Direct regeneration of shoots, roots and whole plant without intervention of callus was obtained from both the explants on MS basal media. In both the explants 100 per cent shoot proliferation was induced in nutrient medium MS + BA 0.25 mg/l + ME 200 mg/l. The shoot proliferation rate was more (5.0) in nodal segment as compare to the shoot tip explant (4.33). Regenerated shoots of more than 2.5 cm length with minimum of 4 leaves were transferred for rooting. Half strength MS medium supplemented with IBA 1.0 mg/l was best for root induction and root initiation within 15.66 days. More than 75 per cent plantlets were survived after hardening period of four weeks.

ABSTRACT

Jasmine is one of the economically most important flower crops cultivated for its fragrant flowers and valuable essential oil. In vitro studies to explore the possibility of regeneration of plantlets from different explants and to undertake biochemical analysis to detect the flavour compounds if present in the in vitro cultures were taken up with local varieties of Jasminum grandiflorum.

Among the different explants tried, leaf bits were found ideal for callus induction, followed by petals and shoot tips. MS medium with 2, 4-D at 1.25 ppm was the suitable medium for callus induction in leaf explants. Miller medium with NAA at 1.25 ppm and BAP at 1.25 ppm was the suitable medium for callus induction in petal explants collected from 18 days old buds of local varieties of Jasminum grandiflorum. Among the different media combinations tried, MS medium supplemented with 0.2 ppm NAA and 0.3 ppm GA₂ is the best medium for callus induction in shoot apex explants of 10mm size. Direct regeneration of plants was obtained in 10 per cent of shoot apex explants cultured in MS medium supplemented with 0.2 ppm GA₁ and 3 ppm BAP in 60 days. A maximum of 95 per cent embryogenicity is induced in leaf callus transferred to MS basal medium supplemented with 1.5 per cent sucrose from MS medium with 2, 4-D at 1.0 ppm.

The peroxidase assay indicated that embryogenic calli had six isoperoxidases while the non-embryogenic had only two. Biochemical analysis of the callus samples showed high Phenylalanine ammonia lyase and phenol indicating the initiation of phenolic pathway, which branches out and ultimately leads to the synthesis of flavour compounds in callus.

ABSTRACT

The present experiment was conducted in order to develop a protocol for rapid in vitro propagation of pomegranate Cv. Mridula. Shoot tip and nodal segment explants selected from mature plant were cultured in MS medium supplemented with NAA and BAP in different concentration and combinations. To control phenolic browning, sub- culturing of cultures was under taken at an interval of first and third day after inoculation. The MS medium supplemented with NAA 0.4 mg/l + BAP 1.0 mg/l showed highest percentage of shoot differentiation with 77.77 per cent and 81.25 per cent response from shoot tip and nodal segment explant respectively. In the same media, earlier shoot initiation as well as more number of multiple shoots/culture were obtained. The shoots when elongated up to 2.5 - 3.0 cm length were transferred for rooting in the ½ strength MS media supplemented with auxins. There was no significant difference for root induction among the type of auxin used either NAA, IBA or both in combination. The concentration of auxins 0.5 mg/l was found to be optimum. Rooted plantlets after hardening in green house gave 49 per cent survival.

ABSTRACT

Shoot organogenesis from several explant types excised from in vitro grown plants of local elite brinjal (Solanum melongena L.) cv. Co2 was studied in response to the supplementation of thidiazuron (TDZ), BAP, IAA and NAA. Cotyledons and leaves were found to be the most responsive explants. High shoot bud induction rate (>50 shoot buds/explant) was achieved in the presence of 0.044 mg/l TDZ. The organogenic calli were subcultured in the same shoot bud induction medium for shoot development. Among different growth hormones, TDZ @0.044 mg/l induced more number of shoots per explant compared to BAP, IAA and NAA combinations. Efficient rooting was observed on half strength MS medium supplemented with 0.5 mg/l IAA. Higher percentage of rooting was achieved only when the well developed shoots were directly transferred to soil.

ABSTRACT

Immature zygotic embryos were isolated from field grown papaya fruits harvested at 90-105 d post-anthesis. The embryos were placed on half-strength Murashige Skoog (MS) medium supplemented with 2, 4-D (2.0 mg l^-1) and cultured under dark for a period of 2 months. The frequency of callus formation was around 66%. After 2 months, calli were transferred onto a half-strength MS basal medium and cultured for 3 months with frequent subculturing (once in 3 wk) on the same medium. The frequency of somatic embryo formation was around 36.6%. The somatic embryos on MS medium supplemented with BAP (0.4 mg l^-1) and NAA (0.02 mg l^-1) germinated and produced shoots. The emerging shoots of 2-3 cm height with 2-3 trilobed leaves were placed onto an MS basal liquid medium with IBA (1.0 mg l^-1) for root induction. The plants developed with shoots and roots were planted in a pot-mixture (sand:soil:FYM) containing VAM.

ABSTRACT

Aprotocol has been developed for the induction, maturation and germination of somatic embryos from leaf explants of Hevea brasiliensis (clone RRII 105). Leaf explants were cultured with their adaxial sides on modified Murashige and Skoog (MS) medium supplemented with different combinations of phytohormones such as 2,4-D & BA, NAA & BA as well as 2,4-D, BA and NAA. Compact calli could be developed from the cut ends of the explants on media containing 2,4-D (1.5 mg/l) and BA (1.0 mg/l) whereas pale yellow friable calli was obtained on media which contained NAA (0.2 mg/l) along with 2,4-D (1.2 mg/l) and BA (1.0 mg/l). The calli formed were detached from the explants and sub cultured for proliferation in medium containing reduced auxin (0.4 mg/l 2,4-D) and slightly increased level of sucrose (40 g/l). Proliferated calli were then sub cultured for embryo induction in modified MS medium supplemented with different auxins and cytokinins. Embryo induction could be achieved in modified MS medium containing BA (2.0 mg/l), GA (1.0 mg/l) and NAA (0.2 mg/l) and maturation occurred in WPM medium containing BA (0.3 mg/l), TDZ (0.5 mg/l) and GA (1.5mg/l). The cotyledonary stage embryos developed into plantlets on transfer to hormone free ½ MS medium. A distinct feature of this study is the induction of somatic embryogenesis from leaf explants of Hevea which has not been reported previously. This explant could be used further as an ideal target tissue for Agrobacterium mediated genetic transformation in Hevea.

ABSTRACT

In the studies on callus induction and somatic embryogenesis in acid lime (Citrus aurantifolia S.) var Sai-Sharbati, different ex-plants and different combinations of growth regulators (NAA, IBA and BA) in MS basal media were tried, the results indicated that cotyledonary segment was the best explant for callus induction among root tip hypocotyl stem, leaf, epicotyl stem and shoot tip explants tested of. The callus grown from epicotyl and hypocotyl stem explant was greenish white and compact. Whereas callus derived from cotylidonary segment and leaf segment was green and friable . Root tip and shoot tip did not exhibit callusing. The callus derived from epicotyl stem and hypocptyl stem explant responded shoot bud formation in MS medium supplemented with NAA 0.2mg/l + BA 0.5mg/l with or without ME 100mg/l. In somatic embryogenesis, full grown callus derived from epicotyl stem explant induced embryo formation within 28.33 days and more shoot bud (6.33) formation.

ABSTRACT

The present experiment was conducted to standardize the composition of nutrient media for callus regeneration. Shoot tip, internodal segment, leaf and hypocotyls of seedling grown under controlled condition were used as explants for callus induction. The study revealed that explants collected from younger seedlings showed greater proliferation of callus as compared to those collected from older one. The basal MS medium as well as WP medium fortified with different concentrations of auxins and cytokinins were tried. Initial better results of profuse callus growth with green colour and compact texture having regenerative capacity were obtained by using leaf explants. In all the treatments, the callus initiation occurred at the cut ends and then spread over the surface of the explant as a result of injury. The level of auxins presumable rises and quiescent cells were stimulated to divide rapidly producing callus. The leaf segment explant induced the callus after 9.50 days in medium WPM + NAA 2.5 mg/l with maximum callus growth (976.75 mg) with green, friable callus which was difficult to subculture. White and friable callus occurred within 12.00 days in MS + 2, 4 - D 5 mg/l. The green and compact callus having vigorous growth was observed in MS + NAA 2.5 mg/l within 12.75 days when subcultured on different regeneration media proved recalcitrant for shoot regeneration. On the regeneration medium the callus turned brown while some callus proliferates to produce white growth around it and dried later on.

ABSTRACT

Aquilaria agallocha Roxb. (Thymelaeceae), otherwise known as ‘Eagle wood’ is a large evergreen tree restricted to the eastern parts of India and Bhutan. The tree is valuable for its fragrant wood - ‘Agar wood’ which is tremendously used in the perfumery and incense stick industries. Lack of rapid natural regeneration and over exploitation has reduced its population drastically. Micropropagation offers a rapid means for clonal multiplication and conservation of this endangered species and attempts were made to standardize available protocol for in vitro multiplication. Media and conditions were standardized for culture establishment and propagule multiplication. Multiple shoots were induced in vitro from nodal segments of 10 yr old trees having enhanced axillary branching. Culture establishmnet was strongly influenced by the nature of the explant and the season of collecting the explants. Nodal segments collected during the period March- April from current season shoots showed a better response (90 %) in half strength Murashige and Skoog medium supplemented with 1.0 mg l^-1benzyl adenine and 0.1 mg l^-1kinetin. The rudimentary multiple shoots induced, proliferated in the basal media supplemented with benzyl adenine (0.1 mg l^-1), naphthalene acetic acid (0.5 mg l^-1) and coconut water (10%). This media also supported further multiplication in serial subculturing with a multiplication rate of 1:6. There exists no earlier report on in vitro multiplication of this tree species valued in perfumery.

ABSTRACT

Kattupadavalam (Trichosanthes cucumerina) is regarded as a laxative and blood purifier, considered beneficial in the treatment of skin diseases. Its entire supply being met from wild, unscrupulous exploitation has led to erosion of genetic resources of this crop. Hence it is imperative that in vitro trechniques are employed to conserve this valuable medicinal species and to evolve feasible protocols for large scale multiplication of this crop. Nodal cultures were established from two months old seedlings of Trichosanthes cucumerina and Murashige and Skoog (MS) medium, supplemented with BA @ 0.5 mg l^-1. Subculture of initiated shoots in the same medium at intervals of three weeks registered enhanced release of axillary buds producing 21 shoots from a single culture at the end of fifth subculture cycle. Elongated shoots were rooted in half strength MS medium, following a pulse treatment with IBA @ 1000 mg l^-1. A single stage root hardening process, wherein, rooted plantlets were subsequently transferred to half strength semisolid MS medium supplemented with 2 per cent sucrose, improved success rate. The rooted plantlets planted out in sterilized media and subjected to a hardening process in a phased manner, survived well.

ABSTRACT

Aloe vera is one of the oldest known therapeutic herb belongs to the family Liliaceae commonly known as guar patta. Gel from fleshy leaves of Aloe vera is rich in 200 nutrients which are used in healing the burns, wounds, gastric ulcers, treatment of diabetes and also used in normal functioning of the liver. Aloe vera is a desert plant which needs water in very less quantity. As Aloe vera is second in ranking in drug production in the world. Government of India is also trying to promote Aloe vera as a crop in dry and semi dry regions of India. As it needs very less and cheaper inputs, Aloe farming promises higher economic gains to farmers. But as the plant grows vegetatively the quality planting material is a problem. Tissue culture provides an opportunity in production of quality seedlings. To optimize the regeneration system in Aloe vera, MS based media were tried to induce shoot formation in cultured shoot tip explants. 6-10 cm long offshoots were collected. Shoot tip explants were cut vertically after sterilization in laminar hood and cultured on MS basal media supplemented with various growth regulators. A total of 23 media were tried for shoot regeneration. All the cultures were incubated under fluorescent light. Different concentrations of BAP (2, 5, 10 mg/l) were used and MS medium with 2 mg/l or 5 mg/l BAP exhibited similar response while BAP at 10 mg/l showed poor shoot formation. TDZ when used at 1 mg/l concentration improved percent shoot formation marginally. Multiple shoots were observed on TDZ containing medium and BAP (2.0 mg/l) supplemented medium in 12-15 days. Multiple shoots were obtained in 12 days when 2 mg/l BAP was added along with 0.18 mg/l IAA. The number of multiple shoots ranged from 4 -15 per explant. The regenerated plants developed roots on MS medium supplemented with 0.1mg/l NAA.

ABSTRACT

Successful in vitro clonal propagation of mature tree of Lasoda (Cordia myxa Roxb) has been achieved through single node explant. Both types of organogenesis of shoot and root formation were obtained by placing nodal explant on shoot induction medium and subsequently on rooting medium. More than 90% culture were responsive for in-vitro axillary shoot proliferation on MS media supplemented with 30g Sucrose 8.0 g agar and a combination of 2.0 mg BA and 0.1 mg NAA per litre. After culture period of 6-8 week, the nodal explants with micro shoot were rooted on the MS media supplemented with30 g Sucrose + 3g activated charcol and different level of NAA (0, 1, 3 and 6 mg/ litre). The season and position of explant on the mother plant was also shown to influence in vitro performance of the regeneration in terms of establishment of aseptic culture, percentage of responsive explants and intensity of leaching of growth inhibitory phenolic chemicals.

ABSTRACT

The mass production of orchids through in vitro approach is now practising on a commercial scale. But, in most cases, it is being done via an intermediate callus which may lead to variability in the progenies. A study was made to standardize a protocol for rapid mericloning of tropical orchid dendrobium cv. sonia from the shoot tip explant without an intermediate callus so as to produce true to type progenies. The efficiency of production of clones through agar gelled medium and shake cultures were compared. The shoot tip explants produced an average of 6-8 multiple shoots on agar gelled (0.8% w/v) MS medium containing 3% sucrose as carbon source supplemented with a hormonal combination of 0.75 mg l^-1 NAA and 2.5 mg l^-1 KIN without an intervening callus, within a period of 3 - 4 months. When the shoot tip explants were cultured in agitated ( 80 - 100 rpm) liquid Vacin and Went ( VW) medium supplemented with 3% sucrose, 2.0 - 2.5 mg l^-1 BA and 0.5 - 1.0 mg l^-1 NAA could induce a large number of protocorms within a period of two weeks. Agitated liquid MS medium supplemented with 0.5 mg l ^-1 IBA and 2 mg l^-1 BA or 0.5 mg l ^-1 2,4 - D, 0.5 mg l^-1 GA₂ and 3.0 mg l^-1 BA was identified as the rapid multiplication medium of the protocorms. About 60 - 80 protocorms could be produced from a single protocorm within a period of 3 weeks. Transfer of these protocorms to agar gelled (0.8%w/v) MS medium containing 2% sucrose supplemented with 20 - 25% coconut milk (CM) was found ideal for plantlet formation of size 1.0 - 1.5 cm within a period of three weeks. Sub culturing of the plantlets to the same medium resulted in rapid profuse rooting. Transfering the rooted plants into bottles containing sterile coconut husk provided with half MS medium without sucrose and hormones was sufficient for in vitro hardening. By this two stage culturing technique, about 50 - 60 true to type clones can be produced from a single shoot apex within a period of 3 months.

ABSTRACT

In Kerala, the commercial cultivation of tomato is limited due to the bacterial wilt disease caused by the soil borne pathogen Ralstonia solanacearum. The release of bacterial wilt resistant varieties like Sakthi, Mukthi and Anagha has increased the area under tomato. But, these varieties are susceptible to tomato leaf curl virus diseases caused by Germini group virus and transmitted by white fly (Bemisia tabaci). The disease incidence varies from 10.77% to 90.5% and the yield loss is tremendous. Unless the tomato variety resistant to ToLCV disease is resistant to bacterial wilt also, it cannot be recommended for cultivation in the State.

The somaclonal variations have been well exploited in developing disease resistant varieties in many crops. Therefore an experiment was formulated to study the somaclonal variations and to screen the somaclones for resistance to tomato leaf curl virus disease in L. esculentum var. Sakthi and L. pimpinellifolium.

The somaclones of Sakthi and L. pimpinellifolium along with the parental lines were planted in earthen pots containing potting mixture with bacterial wilt sick soil. These were screened for resistance to ToLCV disease by artificial inoculation of the vector Bemisia tabaci inside the cages. The observations were recorded on ex vitro survival, biometric characters and reaction to ToLCV and other major diseases.

The ex vitro survival was 46.2% in Sakthi and 36.6% in L. pimpinellifolium. The somaclones of Sakthi showed wide variation for plant height and spread compared to that of L. pimpinellifolium. Some of the somaclones exhibited ‘gigantism’ with potato leaved plants. The yield of the somaclones of Sakthi were higher than that of parental line.

ABSTRACT

Cycas is the largest genus among cycads - the surviving remnants of an ancient line of plants of the early Mesozoic period. The IUCN has classified more than half of the 182 species of Cycadales as endangered, vulnerable or rare. The use of in vitro techniques could permit a way to conserve many of the endangered species. None of the in vitro studies has been successful in establishing a functional protocol for artificial propagation of cycads. The objective of the present investigation is to explore the possibilities of in vitro plant regeneration from megagametophyte explants of Cycas circinalis - the only species of Cycas grown in Kerala. Megagametophyte from the ovules of ten-year-old Cycas circinalis plant was used as explant. Standard tissue culture techniques were adopted for the in vitro culturing of the explant. The basal medium involved major salts of B5 and minor salts of MS media. Glutamine, casein hydrolysate, coconut water and megagametophyte extract were used as supplements. The plant growth regulators - Kn, BAP, 2iP, IAA, NAA and 2,4- D - were incorporated alone and in combinations. Highest percentage of shoot induction and highest average number of shoot buds per culture were observed in PGR combination involving Kn + BAP along with one of the auxins (2,4-D or NAA or IAA). Shoot buds developed did not show further growth even after one year. The protocol employed in the present investigation may lead to multiple shoot proliferation and help in large-scale propagation of Cycas circinalis.

ABSTRACT

To study the influence of season on explant collection, axillary buds from mature trees of three elite genotypes of tamarind viz., Sour pulped type, Red pulped type, and Sweet pulped type (Thailand) were collected monthwise from September, 2002 to August, 2003, sterilized properly and cultured in MS medium supplemented with BAP (1, 1.5, 2, 2.5 and 3 mgl^-1) + GA 0.5 mgl^-1 + NAA 0.1 mgl^-1. The studies revealed that, the bud break percentage was highly dependent on the season of explant collection. In case of Sour pulped type, bud break was recorded during the month of April, May and June. Maximum per cent bud break (50.00 per cent) was recorded in May and June but least number of days were required for bud break (12.33) in April month. In Red pulped type, the bud break was observed during February to June. The axillary buds collected and cultured during the month of February recorded the best results with respect to the per cent bud break (100 per cent) and least number of days taken for bud break (7.12 days). In Sweet pulped (Thailand) type, bud break was recorded during the months of February to June. The axillary buds collected and cultured in the month of may recorded the best results with respect to the percent bud break (87.50 per cent) but March showed least number of days for bud break. Nodal segments cultured on MS + BAP 2 mgl^-1 + GA 0.5 mgl^-1 + NAA 0.5 mgl^-1 gave maximum and early bud break in three genotypes, but sprouted shoots showed abscission of leaflets and died later on.

ABSTRACT

Rose (Rosa hybrida Linn.) is universally acclaimed as the ‘Queen of Flowers’. But this woody plant is considered less amenable to in vitro culture as compared to herbaceous plants. This is due to the fact that the establishment rose explants is difficult due to heavy phenolic exudation. In the present study, this problem was solved by a very simple and cost effective method. The cut ends of the explant were sealed with wax after thorough sterilization. Ten different explant collection periods with 20 different hormonal combinations in MS culture medium were taken for establishment. The winter dormancy period (Mid- December) was considered best for explant collection and showed 85% survival. Amongst the hormonal combinations 5mg/l BA coupled with 0.05mg/l NAA was considered the best. The average number of leaves (7.5) and average shoot length (7.3 cm) was also highest in this treatment, 15 days after culture establishment.

ABSTRACT

Haploids are of great importance in breeding programmes for the production of homozygous diploid lines. This technique reduces the time span in developing new varieties and fixes the traits including recessive ones in the homozygous condition. The haploid embryos or doubled haploid plants could be used in mutation breeding, genetic engineering, biochemical and physiological studies. Isolated microspore culture for the production of haploids has not yet been reported in Hevea brasiliensis. Hence the present work was initiated with the view of producing haploid plants by the culture of isolated pollen grains. The flower bud of the clone RRII 105 at the late uninucleate to early binucleate stage was used for culture initiation. Different pretreatment solutions were tried at different temperatures (4°C, 27°C and 33°C) with the macronutrients of N6 media. Three kinds of callus induction media were used viz. N6, WPM and Hunters medium supplemented with myoinositol (200 mg^-1), glutamate (150 mg^-1), phenyl acetic acid (7.0 mg^-1), sucrose (70 g^-1) and growth regulators. Induction medium include moving liquid, static liquid and semi- solid medium. The ovary co-culture was also tried in the induction medium to increase the frequency of callus formation. Pretreatment of the anther with 0.3 M mannitol at 33°C promoted the division of microspores. Static liquid cultures improved the formation of multicellular microspores compared to semi-solid or moving liquid cultures. N₆ basal medium supplemented with 2.0 mg/l 2.4-D and 1.0 mg/l KIN induced microcalli formation. When the ovary co-culture was included in the callus induction medium, the rate of cell proliferation was increased considerably and the duration of callus formation was reduced from 3 months to 14 days. The results of the present study throws light towards the possibility of regenerating doubled haploids in future.

ABSTRACT

Ophiorrhiza mungos is a rich source of the potent antineoplastic therapeutic agent Camptothecin, which is effective in the complete remission of lung, breast, uterine and cervical cancer. With increasing demand, most of the plants have been indiscriminately exploited from their natural habitat for the isolation of this valuable therapeutic agent. The biotechnological application such as plant tissue culture seems to be a viable option for the production of this high value therapeutic compound without destroying the natural flora. For this purpose various tissue culture techniques have been established to enhance the production of this compound from different parts of O. mungos. The present study revealed that the Physical elicitation with varying doses of irradiation is significantly higher (0.87mg/ g dry weight) than that obtained by chemical elicitation using methyle jasmonate (0.41mg/ g dry weight) compared to control. Biotic elicitors like chitin, chitosan, fungal and bacterial extracts were also used and considerable increase in the production of Camptothecin was obtained in all these cases. Permeabilization with Tween 20 found to be enhancing the exudation of camptothecin (0.021 mg/ml) compared to control (0.0003mg/ml). Hence, the present study gives an alternative for large scale production of camptothecin without affecting the natural flora in a cost effective method.

ABSTRACT

Tinospora cordifolia, a versatile medicinal species with antipyretic and immunomodulatory properties is one of the indigenous sources of the therapeutically valuable alkaloid, berberine. However, the plant contains only meagre amounts of this alkaloid. Hence upgradation of the content of berberine in Tinospora, through biotechnological interventions assumes importance. Four week old leaf, petiole and stem derived calli of two ecotypes of Tinospora viz., Vellanikkara ecotype and Madurai ecotype, subcultured on to Murashige and Skoog (MS) medium, supplemented with various growth regulators, were incubated in light and screened for the presence of berberine employing thin layer chromatography. MS medium with NAA @ 2 mg l^-1 supplemented with BA or kinetin, each at 2 mg l^-1, was identified as the basal production medium for in vitro production of berberine, yielding 7.55 μg and 7.36 μg berberine respectively, per gram of calli. Calli produced from stem segments registered maximum amount of berberine compared to leaf and petiole derived callus cultures. Increasing levels of sucrose in basal medium did not have a favourable influence on the expression of berberine in the test calli. Reducing nitrate and phosphate content of the basal medium to half their strength resulted in enhanced berberine production in in vitro cultures of both the experimental ecotypes. Favourable influence of precursor feeding on upgrading the content of berberine in leaf and stem derived calli of both the ecotypes of the experimental species was also confirmed in the study.

ABSTRACT

Cassava, sweet potato and yams are root and tuber crops propagated through vegetative parts. The CTCRI is maintaining a large collection of (3985 accessions) these crop germplasm in field gene banks. Studies were conducted to transfer these collections to in vitro storage so as to clean off systemic infection and protect them from loss due to biotic and abiotic stress. Suitable media protocols, method of surface sterilization, inoculation and incubation were developed for these different crop species in order to establish initial cultures, for their multiplication and storage under slow growth. Meristem, shoot buds and tuber sprouts were used as propagules for culture initiation.Murashige and Skoog (1962) medium was found suitable for all the species studied with variations required in the concentration of growth regulators (NAA, BA and GA ) for meristem culture and micropropagation. Slow growth of cultures was induced using osmotic retardants like mannitol and sorbitol. Addenda like silver nitrate and activated charcoal was found effective in reducing leaf chlorosis and preventing leaf shedding, thereby contributing to culture life and regeneration capacity. The slow growth media developed were effective in prolonging the subculture period to 18 months (cassava), 10 months (sweet potato), and 20 months (yams). The studies have helped in establishing 400 accessions of cassava, 272 accessions of sweet potato and 166 accessions of yams in In vitro Active Gene Bank. The results are presented and discussed.

ABSTRACT

In vitro pollination and fertilization could be a tool for heterosis breeding of triploid turmeric cultivars, which are almost non-seed setting naturally. Investigations were undertaken to optimize media combinations for the development of in vitro pollinated ovules to mature seed .The half strength MS medium supplemented with auxins and cytokinins was superior to full strength MS. The supplementation of ½ strength MS medium with either auxins or cytokinins at lower concentrations induced some ovule development. The ovule development was more when auxins and cytokinins together were given. The combination of ½ MS +3% sucrose +NAA 0.5mg l ^-1 +BAP 1mg l^-1 showed maximum ovule swelling in cultures. The combinations of BAP 4mg l^-1 with IAA 0.2mg l^-1 produced callusing instead of ovule swelling.

ABSTRACT

Lack of high yielding varieties, variation among progenies through seedling propagation and transmission of viral diseases through sucker propagation together contribute to the decline in productivity of large cardamom (Amomum subulatum Roxb). To increase the productivity of this crop, planting material raised through tissue culture techniques from few selections having higher productivity was considered. From the study, it was revealed that TC plants were superior to conventionally propagated plants due to vigorous growth during juvenile phase, precocity in the yield and higher productivity compared to that of open pollinated seedlings.

ABSTRACT

Central Plantation Crops Research Institute at Kasaragod maintains largest collection of coconut germplasm accessions representing different geographical regions. So far, morphological and isozyme markers were employed for germplasm characterization. To overcome the difficulties associated with the morphological markers, DNA based molecular markers are presently employed for germplasm characterization. In the present study, Inter Simple Sequence Repeat (ISSR) markers are utilized to estimate the genetic diversity among South East Asian germplasm accessions. Nineteen ISSR primers were used to amplify 8 germplasm accessions (4 palms per accession referred as population). The PCR products were electrophoresed in 1.80 % agarose gels. Binary data were analyzed using the software POPGENE ver. 1.32. Dendrogram was constructed based on Nei’s unbiased measure of genetic distance. Nineteen ISSR primers detected a total of 85 polymorphic markers across 32 individuals belonging to eight populations. The average genetic distance among the eight populations ranged from 0.7908 to 0.9327 with a mean of 0.8540. Of the 28 pair wise comparisons the accessions Laguna Tall and Kongthienyong Tall (KTYT) showed the highest genetic identity (0.9327). The lowest identity (0.7908) was between San Roman Tall (SNRT) and Philippines Dalig Tall (PDLT). The Shannon’s index ranged from 0.1615 to 0.299. Diversity parameters viz. number of effective alleles, gene diversity, number of polymorphic markers were calculated for each population. The dendrogram constructed based on the genetic distance revealed clustering of Kongthienyong Tall (KTYT) and Laguna Tall (LAGT) while Philippines Dalig Tall (PDLT) was positioned separately. In the genetic improvement programmes the diverse accessions can be used in hybridization for increased heterosis.

ABSTRACT

DNA based molecular marker technologies have been used extensively to study the genetic relationships and to develop markers for identification of cultivars/varieties in various crops. The present study is an attempt to assess the variability and relatedness among 49 varieties/ accessions of black pepper (Piper nigrum L) based on the data generated by both RAPD and AFLP analyses. The similarity matrix was subjected to cluster analysis and dendrogram generated using the software Ntsyspc 2.1. The dendrogram revealed an average similarity of 63 per cent among accessions. Two selections from the variety Karimunda, namely Sreekara and Subhakara, together formed a single cluster with almost 92 per cent similarity. The dissimilarity observed between the varieties Panniyur 1 and Panniyur 3 the progenies of the same parentage, Uthirankotta and Cheriyakanyakadan was only 18 per cent. Based on RAPD analysis 34 varieties were grouped into 5 clusters. Distinct clustering was not observed in AFLP analysis. The results obtained were correlated with the taxonomical interrelationships reported for these varieties. The overall study has thus helped in understanding the relationship among the local cultivars and released varieties.

ABSTRACT

Grape is a commercially cultivated fruit crop in India. As a result of large-scale introduction, the origin and authenticity of many grape varieties is unclear and the subject of some controversy. Many of the varieties were mixed up and now have led to confusion regarding their correct identification. To explore the genetic relationships between different grape varieties and to analyze their diversity, molecular marker technique has proved to be useful. In the present study, 34 grape varieties have been characterized using Inter Simple Sequence Repeat (ISSR) markers. Out of 93 ISSR primers screened initially, 11-showed good polymorphism. Total 174 bands were obtained, out of which 145 were polymorphic. The similarity indices were calculated using DICE coefficient and NTSYS Pc 2.1 software.

Cluster analysis resulted in the formation of two main clusters. One, of the varieties belonging to Vitis vinifera and other of V. labrusca. Varieties belonging to V. vinifera appeared more diverse by forming distinct sub-clusters based on their colour, flavour and seeds. Out of 34 varieties screened, 10 varieties are grouped in white berries cluster and 15 in coloured (red /black) berries cluster. Three white varieties- Italia, Queen of Vineyard and Thompson seedless are grouped into cluster of coloured varieties. The cluster of labrusca varieties showed homogeneity and had five varieties except Dakh, which belongs to vinifera. It may be wrong introduction. Concord separates initially from all other varieties. Incidentally, Concord is a pure selection from V. labrusca, while varieties like Bangalore blue, Black Muscat, Catawba and Muzzafar Nagar in labrusca group may be the hybrids of labrusca x vinifera. The current study thus revealed that genetic relationship among grape cultivars could be assessed using ISSR markers.

ABSTRACT

DNA fingerprinting is increasingly being used for identification of varieties, quantification of similarity between varieties and study of genetic diversity available in the population.

This is all the more important in crops where morphological variability is less or one variety is known by different names or different varieties are known by same name.

DNA fingerprinting using RAPD method has been standardized for tapioca. Dellaporta method has been used for extraction of DNA and amplification was done following William’s method. This technique has been used for molecular characterisation of accessions and identification of duplicates in the germplasm maintained at Central Tuber Crops Research Institute, Thiruvananthapuram. This technology has been extended for DNA fingerprinting of released varieties and also some of the elite breeding lines.

Eleven varieties released from the institute were fingerprinted using a few primers, which showed high polymorphism in tapioca. One single primer gave distinct banding pattern for all the 11 varieties and it was capable of earmarking each variety.

Individual variety was finger printed for 20 different primers and the results were documented. This technique is being extended to promising land races as well. DNA fingerprinting will be useful for protecting Plant Breeders’ Right as well as Farmers’ Right in the new Patent Regime.

ABSTRACT

Hevea brasiliensis, the main source of natural rubber (NR) is commercially propagated through bud grafting. Since Hevea brasiliensis is a cross-pollinated tree crop, seeds obtained are highly heterozygous. Earlier, plantations were grown from unselected seeds. But due to poor yield and large tree - to - tree variations in growth and yield in such plantations bud grafting with desirable scions is now being adopted for commercial planting. Genetically divergent seedlings grown from open pollinated seeds are used as rootstocks to graft the selected scion. This can lead to stock - scion interactions. Large intraclonal variations observed in growth and yield of bud-grafted clones of Hevea are attributed to the genetic heterogeneity of the rootstocks. Monoclonal and polyclonal seed gardens have been established in Kanya Kumari District of Tamil Nadu for producing good quality seeds. Monoclonal seeds are collected from monoclonal seed gardens where only one clone is planted in a vast area without any interference from pollen grains from other clones. Polyclonal seeds are collected from polyclonal seed gardens where different clones are planted in an area and the seeds are fertilized by pollen grains from all the clones. It is a general assumption that seedlings grown from polyclonal seeds may be highly heterogeneous than seedlings grown from monoclonal seeds. The objective of the present study was to find out the reliability of this assumption by studying the genetic variations existing among the polyclonal and monoclonal seedlings. RAPD analysis of leaf samples from polyclonal and monoclonal viz, RRIM 600, PB 86 and GT1 seedlings was carried out using ten Operon arbitrary decamer primers that gave informative amplification. The results showed that there was no significant difference in the genetic variations among the polyclonal and monoclonal seedlings.

ABSTRACT

The study was conducted to fingerprint and to analyze genetic diversity among 20 genotypes. of Psidium guajava and two species P. friedrichsthalianum and P. cattleianum using random amplified polymorphic DNA. Genomic DNA was isolated using modified CTAB method and polymerase chain reaction was carried out using standard protocols. In all 41 primers were used, 39 of which amplified 376 alleles with 347 polymorphic alleles. All the primers discriminated between two and more genotypes. Primers produced 2-16 alleles. The size of amplified DNA alleles ranged from 0.12-2.2 kilobase pairs. Polymorphic index content value was found to be maximum for primer OPB-12 (0.916). In the dendrogram all the 22 genotypes were grouped into two major clusters. Cluster 1 comprised of Spear Acid, Apple Colour and P. friedrichsthalianum, while Cluster 2 constituted rest of the 19 genotypes. Thus, RAPD markers detected a high level of polymorphism and can be used for breeding of improved guava varieties.

ABSTRACT

An effort was made to characterize twelve ber genotypes using RAPD markers. Of the twenty random decamer primers tested, 17 generated polymorphic bands, while rest of the primers showed monomorphic bands. The primers that amplified all the 12 genotypes were OPC-20, OPD-1, OPD-3 and OPD-4. The size of amplified DNA fragments varied from 0.56-4.26 kilobase pair. In total, 109 bands were obtained, of which 85 bands were polymorphic, while 24 bands were monomorphic. For the cultivars tested between 2-9 bands were obtained for each primer with an average of 5.45 bands per primer. The highest number of bands (9) were generated by OPA-4 and OPD-3. With un-weighted group method using arithmetic mean (UPGMA) cluster analysis, the twelve ber genotypes fell into four major clusters. The pair wise dissimilarities of ber genotypes showed that genotypes G-9 and G-8 were close to each other. Maximum dissimilarity was observed between the genotypes G-8 and G-12.