eChapters

ABSTRACT

Direct shoot organogenesis from several explant types excised from in vitro grown plants of local elite tomato cv. PKM1 was studied in response to zeatin, BAP, IAA and NAA. Cotyledonary leaves were found to be the most responsive explants. High shoot bud induction rate (>25 shoot buds/cotyledonary explant) was obtained in the presence of 2 mg/l zeatin. The organogenic calli were subcultured onto the same shoot bud induction medium for shoot development. Among different growth regulators tested, zeatin @ 2 mg/ l induced more number of shoots per explant compared to BAP, IAA and NAA combinations. Rooting was efficiently induced on half strength MS basal medium supplemented with 0.5 mg/l IAA. The effects of various growth hormones on tomato regeneration on rooting were discussed.

ABSTRACT

In vitro culture induced genetic variation constitutes an important source of variability for the improvement in ginger (Zingiber officinale Rosc.). Hence attempts were made to standardize indirect method of in vitro plantlet regeneration in ginger using various explants like sprouted bud, shoot tip, leaf and pseudo stem. Explants from two cultivars of ginger viz. Maran and Rio-de-janeiro were cultured in Murashige and Skoog (MS) medium supplemented with various levels of 2,4-D and in combination with different levels of BA. Cultures were incubated under two different culture conditions viz. light and dark. Callusing was observed in all the explants except mature leaf in MS medium supplemented with 2,4- D alone (1 - 2 mg l^-1) and in combination with BAP (0.5 - 3.0 mg l^-1). Shoot morphogenesis was achieved from one month old calli in MS medium supplemented with BAP (3.0 mg l^-1). Regenerated shoots were subcultured to medium of same composition for further shoot proliferation and rooting. Plantlets produced were hardened and planted out. From the present investigation, highly efficient protocol for indirect organogenesis in ginger could be developed and the response of two cultivars at various stages of morphogenesis could be studied in detail.

ABSTRACT

In vitro multiplication studies on two peach cvs namely Prabhat and Flordasun grown widely under agroclimatic conditions of Haryana were carried out using nodal and shoot tip explants. Amongst various media modification, M medium containing 1.5 mg^-1 BAP was found the best for shoot induction from both the explants. However, shoot tip showed better response in comparison to nodal explants. Shoot multiplication was highest on M⁷medium (MS+ 6 mg l^-1 BAP). Cultivar response did not differ significantly. Rooting was obtained on M medium containing 0.5 mg l^-1 NAA.

ABSTRACT

Bacopa monnieri (L.) or Herpestis monniera, commonly known as brahmi, purifies the blood, and is useful in scabies, leucoderma, syphilis, diarrhoea and pyresis. As Brahmi is a major ingredient in several ayurvedic preparations, there is growing demand for steady supply of planting materials. Conventional propagation methods are less efficient than in vitro propagation. However, there are only a few reports on the in vitro propagation of this plant. Therefore, an attempt was made to evolve an improved protocol for the in vitro propagation of Bacopa. Shoot tips and nodal buds along with a portion of the stem excised from field grown disease free plants were taken as the explants. After three weeks of establishment on MS basal medium, the sterile cultures were sub-cultured on MS medium supplemented with different concentrations of BA (0.5,1.0 and 1.5mg l^-1). Rooting was induced on in vitro proliferated shoots by culturing on MS basal medium with NAA 1.0 mg l^-1 and IBA 0.5 mg l^-1. Treatments with BA 1.0 mg l^-1 and IAA 1.5 mg l^-1 recorded the maximum number of shoots (40.9 and 35.2, respectively). The height of the shoots was also significantly influenced by the concentrations of IAA (1.5 or 1.0 mg l^-1) in combination with BA (1.0 mg l^-1), recording 5.4 and 5.5 cm. The shoots with an average length of 3.0 to 4.0 cm were kept for rooting. NAA (1.0 mg l^-1) in combination with IBA (0.1, 0.5, 1.0 or 1.5 mg l^-1) produced significantly greater number of roots. The length of the roots was also greater in this treatment. The plantlets were transferred to pots in a greenhouse and later to the field with ninety per cent survival.

ABSTRACT

Rubia cordifolia is an effective blood purifier in indigenous medicine. Habitat destruction and indescriminate harvesting is posing threat to its survival necessitating concerted efforts for conservation. The present study is an attempt to standardise in vitro multiplication protocol, a basic step for in vitro conservation, in Rubia cordifolia. Nodal explants cultured in MS basal medium supplemented with BA 1mg l ^-1 and IAA 0.2 mgl^-1 induced axillary bud break. The in vitro formed shoots developed roots on MS basal medium supplemented with IBA 1mg l ^-1. The plantlets were ready for plant out in 100 days of culture initiation and established well on planting out.

ABSTRACT

In vitro propagation of Plumbago rosea was attempted. One year old plants were used as the source of explants. Nodal explants were inoculated on half strength MS medium supplemented with 2,4-D 1.0 mg l^-1. Induction of callus was observed three weeks after inoculation. The calli were sub-cultured on half strength MS medium supplemented with BA (0.5, 2.0, 3.0 and 4.0 mg l^-1) and IAA (0.0 and 1.0 mg l^-1). Eight treatments with six replications were tried. Benzyl adenine 2.0 mg l^-1 promoted the proliferation of shoots (23.2). Rooting of micro shoots was obtained on MS medium supplemented with IBA 1.5 mg l^-1. The plantlets were then transferred to pots containing sand/soil mixture (1:1) and kept in a mist chamber. The survival rate was found to be 90 per cent.

ABSTRACT

Ipomoea mauritiana (L.) belonging to the Family Convolvulaceae is an important medicinal plant. The roots, leaves and flowers possess medicinal properties. It is used in indigenous medicine as a tonic, aphrodisiac, galactogogue, diuretic, carminative, expectorant and appetizer. It is useful in syphilis, inflammation, leprosy, diseases of blood and in the improvement of voice and complexion. Tender nodal portions from one year old disease free plants grown in pots were used as the source of explants. The explants were inoculated on half strength MS medium containing 3.0 per cent sucrose and 0.6 per cent agar supplemented with 2,4-D 0.5 mg l^-1. All the explants showed callus initiation after three weeks. The contamination free, one week old callus cultures were used for testing the effect of the different treatments. The treatments comprised of different combinations of BA (0, 1.0, 2.0, 4.0 and 8.0 mg l^-1) and NAA (0 and 0.1 mg l^-1) added to half strength MS medium. The highest rate of shoot regeneration was obtained on half strength MS medium supplemented with BA 4.0 mg l^-1. Rooting of the proliferated shoots could be induced on the same basal medium supplemented with IBA 1.0 mg l^-1 and NAA 1.0 mg l^-1. The regenerated plants were hardened in a humidity chamber and successfully transferred to pots, with 90 per cent survival.

ABSTRACT

In vitro clonal propagation of Smilax zeylanica Linn was attempted. Axillary buds from shoot tip and single node explants were induced to proliferate on half strength MS basal medium supplemented with BA (0.5, 1.0 and 2.0 mg l^-1) and IAA (1.0 and 2.0 mg l^-1). Multiple shoots (6.0 - 10.0 per explant) developed from the axillary buds in about four weeks time in all the treatments tried. However, the highest rate of multiple shoot production was in the medium containing BA 1.0 mg l^-1 and IAA 1.0 mg l^-1. Maximum shoot length was also observed in the same medium. Rooting (83.3 per cent) of micro shoots could be induced on MS supplemented with NAA 0.5 mg l^-1. Individual rooted plantlets could be successfully transferred to soil and established in the field with 80 per cent survival.

ABSTRACT

Asimple and reproducible protocol for the rapid propagation of Clitoria ternatea L., a flowering garden climber cum medicinally valuable plant, was developed through somatic embryogenesis from the leaf explants. Leaf segments excised from 12 days old in vitro raised seedlings on inducing callus by culturing in MS medium containing 0.5 mgl^-12,4-D and 0.1 mgl^-1 BAP and sub-culturing callus to MS medium containing 1.0 mgl^-1 BAP, produced numerous somatic embryos within 30 - 45 days. Embryos germinated and produced plantlets with intact shoot and root when they were cultured in MS medium devoid of any hormones and supplemented with GA₂ 0.1 to 1.0 mgl^-1. Elongation of plantlets could be achieved on hormone free MS medium in about 3 - 4 weeks. Well- grown plants on transfer to pots, containing sterile sand, in a growth chamber and three weeks later to the greenhouse gave about 40 per cent survival.

ABSTRACT

Astudy was conducted to establish the regeneration capacity of pseudobulb segments of a Dendrobium hybrid orchid (D. nobile L. x D. chrysotoxum L.) in vitro on full strength (MS) and half strength (½ MS) Murashige and Skoog medium. Pseudobulb segments having 0.3-0.5 cm length cut from the in vitro maintained hybrid orchid were inoculated on both media supplemented with different concentrations and combinations of NAA, BAP and Kn. On MS medium the pseudobulb segments failed to respond, however, in ½ MS medium the explants responded well. Responding explants were maximum (35%) on the medium ½MS + 0.1 mgl^-1 NAA + 0.5 mgl^-1 BAP. An average of two (2) shoot buds per explant were regenerated on ½ MS + 2.0 mgl^-1Kn and ½ MS + 0.1 mgl^-1 NAA + 1.0 mgl^-1 BAP. The regenerated plantlets grew healthily on subculture after separation from the pseudobulb segments.

ABSTRACT

Myriophyllum aquaticum (Velloso) Verdcourt, commonly known as ‘parrot feather milfoil’ is the aquatic plant belonging to the family Haloragaceae. The plant gets the name ‘parrot feather’ from its feather-like leaves arranged around the stem in whorls of 4 to 6 giving it the value of a beautiful aquarium plant. It is a commercially valuable imported aquatic plant used in aquarium plant trade. These plants are exclusively females and as such no seeds are produced. Moreover, current macropropagation techniques are insufficient to produce sufficient propagules for the domestic and export market. Tissue culture techniques offer great opportunities in this regard and attempts were made for micropropagation of this valuable species. A viable protocol has been outlined for the in vitro mass multiplication of Myriophyllum aquaticum. Shoot regeneration was induced from nodal segments and leaves in half strength Murashige and Skoog (1962) medium supplemented with 1.0 mg l^-1 benzyl adenine. Incorporation of 0.2 mg l^-1 kinetin along with benzyl adenine in the culture medium resulted in a marked increase in the frequency (1:20) of multiple shoot formation. The in vitro raised plantlets were successfully rooted, hardened and planted out. The protocol is ready for commercialization.

ABSTRACT

Multiple shoot induction from the cotyledonary node explants of Leucaena leucocephala was studied in presence of various concentrations of TDZ. With the increase in concentration of TDZ from 0.045 μM to 0.227 μM the number of regenerated shoots increased. However, the length of individual shoot decreased. Further increase in TDZ concentration upto 22.71 μM resulted in the formation shoot clusters. Presence of TDZ in the medium inhibited shoot elongation. Transfer of the regenerated shoots to ½ x MS medium supplemented with 0.54 μM NAA ensured elongation of the shoots, which also developed roots. Rooted plantlets were transferred to coco peat for further development and hardening. This highly efficient regeneration protocol may find application in the genetic transformation of this leguminous tree species.

ABSTRACT

The tomato TYLCV tolerant line MP-1 which has high efficiency of crossability & dwarf mutant dg/dg (Manapal) were choosen for the study of enhanced production of plantlets through tissue culture. The cotyledonary explants, hypocotyl sections & decapitated seedlings were taken to assess the regeneration efficiency of the explants as a base for efficient genetic transformation. The decapitated seedlings regenerated much faster (9.3 days) putting forth new sprouts of shootlets which were then transferred to rooting medium. Whereas cotyledonary leaves showed regeneration of plantlets (18.3 days) which is almost double the duration of decapped seedlings. The hypocotyl sections proliferated into callus & regenerated in a much slower rate (27 days). Hence, the faster rate of regeneration from decapitated seedlings served as a efficient base for enhanced production of plantlets during transformation studies. Also the number of harvest of new sprouts (2.3 regenerations) from decapitated seedlings is an added advantage for deriving more plantlets from single seedlings.

ABSTRACT

The tissue culture derived black pepper plants of variety Panniyur 4 were compared with conventional propagules for its vegetative growth and field performance. The in vitro derived plants recorded better rooting, survival rate and shoot growth than the conventional propagules. More than 90% of the TC derived plants recovered after primary hardening and 99% recovered after secondary hardening, while it was only 70% in conventional propagules at both the hardening stages. The secondary roots developed in TC derived plants were observed to be far more superior in number and length. The initial growth rate in terms of plant height, number and size of leaves was much better in TC derived plants. The TC derived plants developed numerous bearing shoots - laterals - in the first year of growth and started bearing in the first year itself. The performance was superior to conventional propagules in which production of laterals and bearing begins much later. Thus the performance of TC derived plants was rated as superior to conventional propagules.

ABSTRACT

The in vitro culture studies in crop plants show that there is a differential response of various explants to different concentrations of auxins and cytokinins. This indicate that hormonal requirement is specific to the genotype and developmental stage of the explant. Therefore standardisation of media and explants were done for in vitro callus culture and plant regeneration in L. esculentum and L. pimpinellifolium at the Department of Olericulture, College of Horticulture during 2000-2002.

The source materials selected for the study were L. esculentum var. Sakthi and L. pimpinellifolium. The explants were leaf segments (0.5 cm²) from fully opened leaves, nodal segments (0.5 cm) and internodal segments (1.0 cm). The media consisted of the basal MS and ½ MS media along with different auxins and cytokinins either singly or in combination. The auxins used were NAA (0, 1, 2 and 3 mg l^-1 and 2,4-D (0.5, 1, 1.5 and 2 mg l^-1) and the cytokinins used were BA and kinetin (1, 2, 3, 4 and 5 mg l^-1).

ABSTRACT

Wood apple is a hardy tree grown in arid and semiarid regions of the country. It is generally propagated through seeds. The traditional methods like budding and inarch grafting require 9 to 12 months for the root stock to come buddable size and thus 1½ to 2 years to become ready for transplanting. The present study was initiated to prepare a grafts within eight months by adopting the micrografting technique. The seeds were sown in the month of April in polybags filled with FYM, sand and soil in equal proportions with a pinch of blitox. The micrografting was done on 1½, 2, 2½ and 3 month old seedling root stock having a diameter of 0.13 to 0.15 cm, 0.17 to 0.19 cm, 0.20 to 0.22 cm and 0.23 to 0.26 cm, respectively. The seedling root stocks were decapitated with the surgical blade and 1 to 2 cm deep split was made. The scion micro bud (1 to 2 cm length and 1 to 2 mm width) of previous season’s growth was inserted in the split. The micropipette cap (0-200 μl) was inserted on the grafted portion. After sprouting of the micro bud, the micro pipette cap was removed. The study revealed that, micro bud grafting success was significantly influenced by the root stock age. Early bud take was observed when the micrografting was done on 2½ month (10.73 days) and 3-month (11.00 days) old root stock. The percent bud take on 3-month old root stock was significantly higher (99.33 per cent) than the rest of root stocks. Micrografting done on 3-month old seedling root stocks in June-July is suggested for quick multiplication of woodapple.

ABSTRACT

Attempts were made to induce variability by irradiation of axillary buds of rose cv. Folklore followed by in vitro culture. Axillary bud explants collected at different growth stages were subjected to gamma irradiation at different doses (20, 30 and 40 Gray). The in vitro induced micro shoots were sub cultured on a rooting medium (M.S. basal medium supplemented with IAA 1.00 mg/l + NAA 1.00 mg/l + activated charcoal 500 mg/l). The rooting percentage was the lowest in explants irradiated with 40 Gy. Rooting efficiency was severely affected when buds were collected at vegetative phase. Significant interaction between bud stages and gamma rays was noticed for days to root initiation and number of roots per culture. Gamma irradiation at 30 and 40 Gy significantly delayed root initiation at all stages of buds exposed. Significant reduction in number of roots/ culture, and root length was observed at higher doses of gamma exposure. The reduced rooting efficiency may be due to inhibition of cell division on account of chromosome damage.

ABSTRACT

Protoplast isolation of Piper nigrum L.and Piper colubrinum Link. was attempted using axenic leaves at two different osmotic potentials viz. 0.60 and 0.65 molar (M) osmoticum. In Piper nigrum, highest protoplast yield (6.90 x 10⁴ protoplasts ml^-1) was observed in the enzyme combination 1.40 per cent cellulase and 0.310 per cent pectinase while in Piper colubrinum, highest protoplast yield (13.0 x 10⁴ protoplasts ml^-1) was observed in the enzyme combination 1.0 per cent cellulase and 0.217 per cent pectinase during 21 h of digestion. In both the species, 0.6 M osmoticum was found to be optimum to maintain the osmotic potential of the isolation solution. Filtration-centrifugation technique was found to be superior in purifying the protoplasts of Piper species compared to sucrose floatation method. Centrifugation at 1000 rpm for three minutes was found to be best in purifying Piper nigrum protoplasts. For purifying Piper colubrinum protoplasts, 600 rpm for three minutes was found optimum. The protocol developed for protoplast isolation in Piper species can be used for biotechnological means like somatic hybridization between the two and gene transfer to develop foot rot resistant black pepper lines.

ABSTRACT

Cultivated turmeric consists of fertile short duration types with a chromosome number of 2n=84. In vivo crossing was done between two short duration types VK 70 and VK76 to develop a high yielding variety with high curcumin and curing percentage. Seed set and seed development was obtained by in vivo stigmatic pollination. Hybrid seed germination was obtained under in vitro in dark on moist filter paper and the seedlings were micropropagated to establish a population of six plantlets /seedling with in a period of 10 months. The multiple shoots were obtained in the medium of half strength MS + 3 per cent sucrose+ BA 2.5 mg l^-1+ NAA 0.5 mgl^-1. Coupling conventional breeding with tissue culture reduces the breeding time.

ABSTRACT

Protoplast isolation in orchids is considered to be a valuable tool for introduction of desirable traits through somatic cell fusion. The present work on the protoplast in Dendrobium var.sonia is undertaken with a view to standardize protocol for isolation and regeneration. Tender leaf mesophyll tissues of one-month-old Dendrobium var.sonia were used as explant for protoplast isolation. The leaf tissues were treated with enzyme mixture of cellulase 1per cent (Onozuka -R from Trichoderma viride) and macerase 0.25per cent (from Aspergillus niger) for 16 hours. Protoplast from the Dendrobium var. sonia was successfully isolated and regeneration of shoots and roots were obtained in MS medium containing BA 5mg l^-1+NAA 1mg l^-1.The plantlets were hardened in a span of five months.

ABSTRACT

Aprotocol for in vitro clonal multiplication of Dendrobium var. Betty Ho is reported. Aseptic shoot tip explants cultured in MS medium containing Benzyl Adenine (5 mg l^-1) and casein hydrolysate (1000 mg l^-1) recorded a maximum multiplication rate of 10 fold in 30 days. Explant cultured in LS) medium supplemented with 1-napthalene acetic acid (0.1 mg l^-1) and Kinetinetin (1 mg l^-1) developed a maximum of 8.3 shoots in 30 days. Shoots thus obtained were rooted on MS medium supplemented with BA (0. 1mg l^-1 ) and NAA (0.5mg l^-1). Rooted plantlets after hardening were transferred to green house.

ABSTRACT

Plants as a source of medicine are of special importance in the countries like India which has well developed traditional system of medicine which derive more than 90 per cent of medicaments from higher plants. Several of these also constitute important ingredients of Allopathic medicines. Most of the requirements for the medicinal plants are met from wild sources. But due to the changing ecological factors in the forests and unserupulous collection of medicinal plants, the wealth of medicinal plants is getting depleted and some types have already become extinct. The collection of these plants from the forests cannot cope up with the ever increasing and changing demand from the pharmaceutical, perfumery and cosmetic industry. In order to provide regular and sustained supply of medicinal plants, it is essential now to domesticate and systematically cultivate these plants for which large scale availability of planting material has to be ensured. In this context, in vitro multiplication protocols were standardised for rare, valuable and endangered medicinal plants such as Holostemma ada-kodien, Trichopus zylanicus, Aristolichia indica and Terminalia chebula. The study indicates the feasiblity of rapid multiplication of these plant species using in vitro techniques and the standardised protocols could be used to generate large number of true to type protocols within a short time.

ABSTRACT

Medicinal plants are the most important source of life saving drugs for the majority of the world’s population. Therefore the biotechnological tools are important to select, multiply and conserve the critical genotypes of medicinal plants. With the increase in the demand for the crude drugs, the plants are being overexploited, threatening the survival of many rare species. Also, many medicinal plant species are disappearing at an alarming rate due to rapid agricultural and urban development, uncontrolled deforestation, and indiscriminate collection. Advanced biotechnological methods of culturing plant cells and tissues should provide new means for conserving and rapidly propagating valuable, rare, and endangered medicinal plants. Maintenance of germplasm in the green house or in the field has many difficulties and so there is a need for the in vitro conservation of these plant germplasm. In the present paper we report the in vitro conservation of two medicinal plants and each of it has its own medicinal value. The tuberous roots of Holostemma are medicinally important and are utilized as a major ingredient of the drug ‘jivanthi’. Tylophora is used as a herbal medicine and the plant has been traditionally used as a folk remedy for the treatment of bronchial asthma, bronchitis and dermatitis. Shoot buds of these plants were cultured in Murashige and Skoog’s (1962) medium with different strengths and with different concentrations of sucrose and mannitol. The different treatments induced varied response with respect to the slowing of growth of cultures. Sucrose was found essential in combination with mannitol to induce maximum reduction in the growth of the plant tissues. The cultures could be maintained without sub culturing for over one year and resumed normal growth on transfer to mannitol free medium. This method of conservation has many advantages.

ABSTRACT

Cashew (Anacardium occidentale L.) is a woody perennial tree of tropical origin, belonging to the family Anacardiaceae. Cashew is being cultivated in India, Brazil and Africa countries. It is well known for its food, noon food and medicinal uses. In vitro clonal propagation of cashew, which is an effective method for large-scale multiplication of trees was tried. Cashew plantlets were regenerated from shoot explants of 2 - 3 year old grafted plants, which were regularly sprayed with Bavistin 0.1 per cent at weekly intervals. Among the different surface sterilization treatments used, a combination of antioxidants, antibiotics and fungicides was found to be better with around 40 per cent contamination free cultures being obtained. MS medium containing full strength macro elements supplemented with Kinetin (5 mg l ^-1), NAA (1mg l ^-1) and Brassinolide (0.1 mg l ^-1) was found to be best for shoot proliferation and shoot elongation. Micro shoots were rooted in vitro at a frequency of 70-80 per cent, when cultured for 4-8 days in quarter MS liquid medium supplemented with IBA (1mg l ^-1) after the pulse treatment with IBA (100 mg l ^-1) for two minutes. The average number of roots ranged from 3 - 5 with an average length of 1.63 cm. About 50 - 60 per cent of the rooted microshoots survived wearing and produced healthy and vigorously growing plants, which were transferred successfully to the field.

ABSTRACT

Asuccessful micro grafting technique in Cashew (Anacardium occidentale L.) was developed using in vitro germinated seedling as root stock and shoots from stage II cultures as scions. Grafting success was dependent on the method of grafting, size of the scion and age of the root stock. Among the methods tried, side and cleft grafting were found to be suitable. Due to the ease of operation and faster union, side grafting was preferred. High levels of graft union were obtained when 2 - 3 cm long shoots from stage II cultures were grafted on to 8 - 9 days old in vitro raised root stocks in full strength MS (Murashige and Skoog) medium supplemented with Kinetin (2.5 mg l^-1), NAA (0.5 mg l^-1) and Brassinolide (1mg l^-1). The very high growth of grafted scion was obtained, when the micro grafts were transferred into MS medium containing full strength macroelements supplemented with Kinetin (5mg l^-1), NAA (1mg l^-1) and Brassinolide (1mg l^-1). The micro grafts after a process of hardening could be successfully transplanted into soil. Micro grafting techniques standardized could be used for rejuvenation of shoot explants of mature tree.

Introduction

At the Banana Research Station, Kannara activities focused on Musa germplasm conservation and evaluation are in progress. The aim of the project is to collect and conserve wild and cultivated germplasm representative of the diversity existing in the Musa genepool for evaluation and subsequent use in breeding programmes and to make available selected superior material to the farmers of Kerala. The center presently holds a Musa germplasm of 256 accessions in its field gene bank. These accessions have been characterized and evaluated as per INIBAP/IPGRI Musa descriptors and a database developed.

In a vegetatively propagated crop like banana, in vitro culture is widely employed in germplasm introduction and conservation and is an essential requirement for the safe movement of germplasm (Sharrock and Engels, 1996). By this method, germplasm material is readily propagated, thereby facilitating the dissemination of disease free plants. Since 2001, efforts have been made at Banana Research Station, Kannara to introduce forty new exotic accessions employing in vitro culture for conservation and evaluation. These are material from the global Musa germplasm collection maintained by International Network for the Improvement of Banana and Plantain (INIBAP), France and supplied by National Bureau of Plant Genetic Resources (NBPGR), New Delhi.

Introduction

Musa species and cultivars are identified mainly on the basis of morphological characters. Somatic mutations and changes brought about by environment are major obstacles to the accurate identification of clones (Kaemmer et al., 1992). Isoenzymatic markers provide an additional tool for the characterization of germplasm and have been successfully employed in banana to provide better understanding of somaclonal variants and to detect genetic differences at clonal level.

Being located within the center of diversity of cultivated banana, the South Indian state of Kerala accounts for a large share of variability, especially the AA, AB, AAB and ABB genomic groups.Nendran, the French plantain cultivar indigenous to Kerala (Jacob, 1952) is represented by many ecotypes/clones. Other prominent cultivar groups include Mysore (AAB), Rasthali (AAB), Neypoovan (AB), Kunnan (AB), Monthan (ABB) and Karpooravalli (ABB). The variability has been collected and conserved in the field at the Banana Research Station, Kannara. These have been characterized morphologically employing per INIBAP/IPGRI Musa descriptors, facilitating the identification of distinct cultivars, clones and synonyms.This project was initiated to survey the isozyme polymorphism in the cultivar groups and to select suitable system for clonal identification.Results of the study employing three enzymatic systems -esterase, diaphorase and peroxidase are presented

ABSTRACT

The cry1A genes of Bacillus thuringiensis (Bt) are widely used to engineer lepidopteran insect resistance in crop plants including horticultural crops. Continuous exposure of a single kind of Bt toxin can lead to resistance development in insect pest. Due to the difference in structure and unique insecticidal mechanism, cry2A genes are promising candidates for management of resistance development. Since India is rich in biodiversity and genetic resources, indigenous Bt strains are valuable tool for identification of novel cry genes. The present study describes the cloning of cry2Ab from a new indigenous strain of Bt, 14RI. The presence of cry2Ab gene in Bt strain 14RI was confirmed by PCR with primers specific to its internal region. Primers corresponding to the flaking region of cry2Ab were used for amplification of cry2Ab orf from the Bt strain 14RI. The amplified cry2Ab orf was first cloned into the T/A cloning vector, and then fused to the downstream of the cry2Aa promoter along with its orf1 and orf2 in the Bt shuttle vector pHT1301. Acrystalliferous Bt strain 4Q7 has been transformed with recombinant pHT1301 to express the cry2Ab of Bt strain 14RI.

ABSTRACT

Role of cytokinins in the regulation of sink development in potato was studied by transgenic approach. Transgenic potato plants over-expressing Agrobacterium native ipt (gene for isopentenyl transferase, rate limiting enzyme in cytokinin biosynthesis) under the transcriptiona l regulation of tuber specific patatin promoter were developed. Transformants obtained showed normal phenotype, while the cytokinin levels showed significant increase over the control plants for the various cytokinins tested, viz., trans zeatin riboside (tZR), dihydrozeatin riboside (DHZR) and isopentenyl adenosine (iPA). The primary transformants were hardened and tested under green house conditions. Green house studies showed a significant increase in the number of tubers in ipt transformants when compared to the wild plant as well as GUS transformant. However, the total weight of tubers did not show appreciable difference between transformants and control plants. Reduction in the weight of individual tubers appears to be due to source limitation.

ABSTRACT

Chilli (Capsicum annuum L.) is a vegetable and spice crop of worldwide importance. Despite the fact that other closely related members of the Solanaceae family are easily transformed by genetic engineering, capsicum still remains recalcitrant to in vitro manipulation, due to lack of proper elongation of multiple shoot initials. An attempt has been made to standardize transformation protocol in two local cultivars of capsicum viz., Byadgi dabbi and Sankeshwar, using shoot tip explants.

The Shoot tip explants were co-cultivated (for 2 days) with Agrobacerium strain EHA105 harboring pBinBt3 plasmid having cry1AC gene and nptII marker linked to the CaMV 35S promoter and nos terminator. After co-cultivation shoot tips were transferred to MS medium containing 2mg/l IBA, 100mg/l kanamycin and 300mg/l cefotaxime. Survived plants were checked for the presence of transgene using cry1 AC and npt II specific primers. Expression of cry1AC gene in these plants was checked using DesiGen Xpresstrips.

ABSTRACT

Chilli is the universal spice of Kerala, known for its pungency, flavour and colour of fruits. Of the five domesticated species of Capsicum, C. annuum is the most extensively cultivated one. Bell pepper (C. annuum L.) is mainly used as a vegetable, because of its low pungency and good flavour. It is used as raw in salads, and also in cooked form. Application of biotechnological tools in this crop for improving the quality, shelf life and tolerance of the crop to stress conditions has been limited. This is mainly due to lack of an efficient regeneration system. We reported a viable protocol for the regeneration of whole plant from the hypocotyl earlier. We also succeeded in developing a protocol for genetic transformation of bell pepper using Agrobacterium tumefaciens. The strain EHA 105 containing gus intron and npt II was used for co-cultivation. The dilution of bacterial culture and time of infection were standardised. This was followed by killing the bacterial cells using cefotaxim @ 250ppm. Transformants were selected on MS medium supplemented with kanamycin. Staining of the regenerants with X-gluc revealed presence of blue spots, confirming transformation. This protocol could be exploited for improving the commercial traits of bell pepper by incorporating desirable genes through Agrobacterium mediated transformation.

ABSTRACT

Holostemma ada-kodien K. Schum, is a laticiferous climber belonging to the family Asclepiadaceae. The root tubers of the plant are medicinally important and are utilized as a major ingredient of the drug, Jivanti. The roots of Holostemma are sweet, ophthalmic, emmolient, alterant, tonic stimulant, aphrodisiac, expectorant and galactagogue and are useful in ophthalmopathy, orchitis, cough, burning sensation, stomachalgia, fever and to cure ‘tridosha’ (Warrier et al., 1995). The sugars and amino acids present in the tuberous roots are responsible for the medicinal properties (Ramiah et al., 1981). There is a huge demand for the root tubers of Holostemma in the South Indian pharmacies and more than 150 metric tons of roots are needed every year (Nair et al., 1992). The destructive and ruthless collection of tuberous roots in recent times has led to acute scarcity of the plant and consequently it has been listed as vulnerable and rare in the FRLHT red list of medicinal plants (FRLHT, 1997). Extending the commercial cultivation of Holostemma is practically impossible due to the increasing land pressure and the perennial nature of the crop. An alternative to meet the increasing demand is to produce the active chemicals in Holostemma through in vitro techniques. In vitro techniques have been extensively studied to produce the different secondary metabolites from various medicinal plants. A strong correlation between secondary metabolite production and morphological differentiation gives more impetus to the application of organized cell culture particularly the root cultures for the large-scale production of phytochemicals in vitro. Transformed root cultures - the so called hairy root cultures obtained after the insertion of T-DNA from the root inducing (Ri) plasmid of the Agrobacterium rhizogenes into the plant genome (Ackermann, 1977) has emerged as an important tool for the production of secondary metabolites in vitro (Rhodes et al., 1987). Hairy roots have advantages of fast growth, organ differentiation and stable secondary metabolite production (Banerjee et al., 1995). We report here the hairy root induction from shoot buds and seedling hypocotyls in infection with A. rhizogenes useful in exploring the possibilities of large-scale in vitro secondary metabolite production in this rare medicinal plant.

ABSTRACT

Soft rot of ginger caused by the fungus Pythium aphanidermatum is a major disease affecting ginger cultivation. To combat invading pathogen in the event of infection plants are known to produce antimicrobial pathogenesis related proteins (PR proteins) prominent among which are antifungal hydrolases like glucanases and chitinases. Since Pythium lacks chitin in its cell wall, increase in level of glucanase in the plant may enhance the resistance of ginger to soft rot disease. Signal molecule like ethylene plays a prominent role in the defense response of plants. The present study was undertaken to investigate the role of ethylene in enhancing the level of glucanase in the ginger system. Detached leaves of Rio de Janeiro variety of ginger were used in different experiments. Leaves were treated with ethephon at different concentrations and different time intervals. Increase in the glucanase activity by ethephon treatment was quantified by enzyme assay using crude protein extract. Glucanase levels showed an initial increase with increasing concentration of ethephon but decreased at higher concentration (5 mg/ml). A longer exposure of detached leaves to ethephon (48 h) resulted in 3.7 fold increase in glucanase activity compared to control. The level of enhancement of the glucanase transcript also followed a similar trend as revealed by RT PCR analysis. Two acidic isoforms of glucanase were detected using native PAGE and their levels were found to be enhanced by treatment with ethephon. An increase in the levels of glucanase may contribute to the plant’s ability to resist infection by Pythium.

ABSTRACT

Microbial antagonists not only reduce the soil borne disease, but also influence the growth of crop plants. In a study conducted for five years on the effect of microbial antagonists on damping off incidence and biometric characters of solanaceous seedlings, it was observed that seed treatment and soil application of Trichoderma viride, T. harzianum, Pseudomonas fluorescens, Azotobacter chroococcum reduced the damping off incidence considerably in brinjal, chilli and tomato. Application of these microbes also increased the per cent germination and promoted vigour of solanaceous seedlings as compared to control. Among the various antagonists, T. viride was the most effective one reducing the damping off diseases as well as promoting the growth of solanaceous vegetables.

ABSTRACT

An In vitro study was conducted to evaluate the fungicidal efficiency of four selected fungal antagonists against leaf spot pathogens of ivy gourd by dual culture method. The antagonists evaluated were Trichoderma viride, Trichoderma harzianum, Aspergillus niger and Chaetomium globosum. The major leaf spot pathogens of ivy gourd used for the study were Cercospora cocciniae, Colletotrichum gloeosporioides and Alternaria alternata, causing severe infection on the foliage. Among the four antagonists tested, T. viride and T. harzianum were found to be the most effective recording the highest AI value of 1500 against all the three pathogens followed by A. niger. C. globosum was least inhibitory on C. gloeosporioides and A. alternata, but was effective against C. cocciniae. A complete overgrowth of the antagonists on all these pathogens were observed in the case of T. viride, T. harzianum and A.niger. C. globosum showed aversion to the hyphal growth of C. gloeosporioides and A. alternata, whereas in C. cocciniae, a homogenous growth was observed.

ABSTRACT

The antagonistic organisms are known to bring out action on the pathogen by various mechanisms. Based on in vitro screening of epiphytic microbes from cocoa pod surface against Phytophthora palmivora, the incitant of pod rot of cocoa, a promising isolate of Trichoderma viride and two isolates of Pseudomonas fluorescens were selected. The mechanisms of antagonistic action of these selected epiphytic antagonists against P. palmivora were studied in comparison with the standard cultures of T. harzianum and P. fluorescens. The selected epiphytic fungal antagonist T. viride and standard culture of T. harzianum were found to be efficient parasites of P. palmivora. The hyphae of the pathogen were seen tightly held by coiling with hyphae of the fungal antagonists. The hyphae of the antagonists penetrated the host hyphae at several points and grew to its inner cavity. The fungal antagonists also caused disintegration of the pathogen hyphae, besides free intermingling, which resulted in malformation of host hyphae. The ability of the two epiphytic P. fluorescens isolates and standard culture of P. fluorescens in producing HCN and siderophores was assessed. It was found that these isolates produced HCN and siderophores in appreciable levels thereby suppressing the P. palmivora. Though, more than one mechanism may operate in suppressing the pathogen, the relative importance of a particular mechanism may vary with different conditions, which needed to be further investigated.

ABSTRACT

In Kerala, apart from cultivated sesame species (Sesamum indicum L.) three wild species were identified viz. Sesamum malabaricum, Sesamum mulayanum and Sesamum radiatum. An investigation was carried out to determine the intensity of arbuscular mycorrhizal fungal colonization in cultivated and wild species of sesame. The percentage of arbuscular mycorrhizal fungal infection in roots of different sesame species were found to be variable. The highest percentage of root colonization of arbuscular mycorrhial fungi was found in wild species S. malabaricum, which promotes tolerance to the plant under drought stress conditions.

ABSTRACT

The Cry2A proteins are promising candidates for managing the development of Cry1Ac resistance in insects. The Cry2A class of proteins is different from that of Cry1A, and experiments have shown that insects resistant to Cry1Ac are not cross-resistant to Cry2A proteins. However, the Cry2A proteins are less toxic than Cry1Ac to the polyphagous pest Helicoverpa armigera. Structure-based protein engineering of Cry toxins may pave the way for directed evolution of variants with broad spectrum of insect species specificity, enhanced potency, and stability. In the present study homology modeling of Cry2Ac was done using DeepView software. The template for Cry2Ac protein sequence (accession number X57252) was selected using ExPdb template search. The raw sequence of the Cry2Ac was superimposed over the Cry2Aa PDB template (1I5P). The superimposed model was submitted to the SWISS Model server. After receiving the Cry2Ac model, energy minimization was done using Gromos96. The threading energy and force field energy were calculated. The homology model of Cry2Ac made by us along with the Cry2Ac model from the SWISS-MODEL Repository was used for comparative analysis of receptor binding regions of Cry2Aa. Results showed variation between the two highly homologous Cry2A proteins in their receptor binding regions which may account for differences in spectrum of insecticidal activity.

Seeding or sowing is an art of placing seeds in the soil to have good germination in the field. A perfect seeding gives a) Correct amount of seed per unit area. b) Correct depth at which seed is placed in the soil. c) Correct spacing between row-to-row and plant-to-plant. Seed drill is a machine for placing the seeds in a continuous flow in furrows at uniform rate and at controlled depth with or without the arrangement of covering them with soil. Planter is normally used for those seeds which are larger in size and cannot be used by usual seed drills. A planter consists of: (i) hopper (ii) feed metering device (iii) knock out arrangement (iv) cut-off mechanism (v) furrow opener and (vi) other accessories. A planter has seed hopper for each row.

Ergonomics (also known as Human Engineering, Human Factors or Human Ergology) is the scientific study of relationship between a person and his/her working environment. The term environment includes the tools, materials and method of work, ambient conditions and physical environment in which the work is carried out, and also the organizational factors. Ergonomics application can help in increasing the efficiency and productivity, reducing drudgery and occupational health problems, and enhancing safety of workers in various activities.

Transfer of technology is closely associated with generation of technology and its use leading to development. Extension components contain stimulating inputs that would mobilize the practitioners to put recommendations into action. Sustainability in agriculture is very important component of present day agriculture and future aspirations. Keeping these aspects in view an attempt was made to enlist suggestions under extension approaches that would enhance sustainability in agriculture in the area under study. The suggestive extension measures to enhance sustainability in agriculture were studied under components of social structure, cooperation mechanism, evaluation technique and marketing network.

Growing population, rapid urbanization and changing climate have created a global challenge to meet the food and nutritional needs. In India, rapid urbanization is not only taking place in larger cities, but satellite towns are competing for food, water, transportation and above all adding to pollution of the environment. As warming of the climate gathers alarming pace, posing a danger to agriculture, greenhouse cultivation is the only answer to save crops of flowers and vegetables. The yield under polyhouse cultivation can be achieved to the level of 5-8 times as compared to open field cultivation.

PROTECTED STRUCTURES

Protected cultivation is unique and specialized form of agriculture. Protected or greenhouse cultivation of vegetables is one of the means for clean vegetable production in peri-urban areas. The protected cultivation facilitates year-round production of high- quality produce with minimum labour and irrigation water, and almost wards off pest problem. In peri-urban regions, where climate prevents or does not favour year-round production of crops in open field, vegetable production can be taken up in protected environment. Use of protected structure for cultivation of crops as a commercial venture is a recent phenomenon, especially in the tropical areas.

Fusarium wilt of carnation caused by Fusarium oxysporum f.spp dianthi causes severe yield losses under protected cultivation. For the management of Fusarium wilt, 27 isolates of Bacillus strains were isolated from the rhizosphere of different crops including carnation. Among various species of Bacillus, Bacillus amyloliquefaciens (BSC7) was identified as a most virulent antagonistic bacterial isolate. Studies on antagonism under Environmentally Controlled Scanning Electron Microscopy (ESEM), depicted the presence of rod shaped bacterial cells with biofilm formation at 44847x. Detection for the presence of antibiotic biosynthetic genes reflected the presence of surfactin, iturin, bacillomycin and fengycin genes. The 24 isolates of Bacillus spp. showed positive reaction for surfactin gene. Nineteen isolates were amplified for Iturin A gene except BS5, BS9, BSC1, BSC2, BSC11, BSD1 and BSD2. Strains of B. subtilis BS1, BS2, BS5, BS6 and BS8 expressed Bacillomycin D gene. The genomic DNA of strains BS1, BS2, BS4, BS6, BS7 BS8, BS11 and BS14 showed positive for Fengycin D gene. The isolate of B. subtilis BS2 showed positive reaction for four genes namely surfactin, iturin, bacillomycin and fengycin.

In vitro screening of Bacillus, B. amyloliquefaciens (BSC7), P. aeruginosa (P1) and T. viride (TV1) showed highest inhibition against F.oxysporum f.sp.dianthi to an extent of 55.95, 55.29 and 81.61 per cent over the control respectively. The antifungal activity of antagonistic B. amyloliquefaciens BSC7 and T. viride TV1 against F.oxysporum f.sp. dianthi was confirmed under ESEM by observing disintegration, lysis and structural abnormalities of the hyphae of the pathogen at the zone of interaction.

Recent Initiatives by National Research Centre on Seed Spices, Ajmer

Standardization of the drying techniques

In fennel five methods of grain drying were employed viz., shade dryer (30°C), sun dryer (35°C to 37°C), solar dryer (40°Cto 42°C), vegetable dryer (50°C) and multipurpose grain dryer (60°C). Fennel grains which were dried under solar dryer, gave maximum test weight (5.17 g), recovery (39.82 %) with lowest moisture content (61.30%) and highest taste marks (9.3) and colour marks (9.2).

Technique to collect fresh and hygienic inflorescence sap (Neera) from coconut

In the traditional method of collecting sap, the inflorescence to be tapped is connected with an earthen pot/bamboo receptacle for the sap collection. Spadix to be tapped is tied with plastic rope and a small portion is sliced off from the top. The spadix is gently stroked with a mallet in the morning and evening. After a period of 8 to 10 days, sufficient sap starts oozing out from the cut end. A type of clay soil, a gummy material or leaf extract is pasted on the surface and sides of the cut end. Since the sap is highly nutritious, both enzymatic and microbial fermentation takes place. The total sugar reduces progressively and it becomes more acidic and develops a harsh odour and becomes unpalatable. In order to prevent fermentation, lime is coated inside the pot. The above method is not hygienic and attracts lot of insects, ants and contaminates from pollen and dust particles. In order to collect the sap fresh and hygienic, a simple device was developed.

Azadiractin (1%) was found effective for the control of Hadda beetle on Ashwagandha. Nineteen arthropods were recorded on isabgol. Among them, 13 were phytophagous species belonging to order Lepidopteran (09), Hemipteran (03) and Homopteran and six predatory species belonging to order Coleoptera (03), Neuroptera (01) and Odanata (02). The sequential occurrence of arthropods revealed the presence of aphid (Aphis gossypii) from second week of January to fourth week of February, whereas Lepidopteran (Helicoverpa armigera, Trichoplusia ni, Thysanoplusia oricalchae, Spliarictia sp. Hyposidra successari and Olene mendosa and true bugs (Graptostethus servus and Spilostethus pandurus) were observed associated during early crop growth stages (i.e. from second week of December). Infestation of aphid was uniformly severe, whereas that of Lepidopterans and true bugs were sporadic and less severe. However, presence of these pest arthropods caused significant reduction in seed yield.

Agricultural Seasons

Season is defined as “part of the year during which a distinguished type of weather prevails”.

A) Seasons of Temperate region

1. Spring (March – May) is the first season of the year in which plants being to grow and leaves emerge.
2. Summer (June – August) is the second and warmest season of the year out side the tropics during which plants flourish
3. Fall or Autumn (September – November) is the third season of the year in which leaves turn brown.
4. Winter (December – February) is the last and the coldest season of the year. Many trees loose their leaves.