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M. Sc. Dissertations

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20112
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Author: Rajesh Kumar × End date: 2011 × Start date: 2011 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Tissue culture studies in Alfalfa (Medicago sativa Linn.)
    (CCSHAU, 2011) Rajesh Kumar; Kharb, Puspha
    In the present investigation attempts were made to develop an efficient protocol for in vitro plant regeneration in Medicago sativa L. Initiation of callus formation from hypocotyl explants was observed within 13-15 days of culture. Initiation of callus formation from cotyledons explants was observed within 13-15 days of culture. Maximum callus formation was obtained in R3 medium containing MS basal + NAA (1.0 mg/l) + Kinetin (0.3 mg/l). Maximum number of shoots was obtained in R12 medium containing MS basal + NAA (1.0 mg/l) and Kinetin (0.5mg/l). MS basal medium was used for roots induction, roots were observed after 14 days with very good quality.In media R2 (MS basal + NAA 0.1mg/l + 2 IP 1.0 mg/l) and R8 (MS basal +NAA 2.0 mg/l), when shoots were left little longer rooting occurred. After transplantation, 73.3% plants survived and these plants looked normal with no morphological changes in leaf structure and plant type.Thus in the present study, regeneration protocol in Medicago sativa L variety T9 has been developed using hypocotyls and cotyledon explants.
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    ThesisItemOpen Access
    Evaluation of entomopathogenic nematodes against Plutella xylostella (L.) on cabbage
    (CCSHAU, 2011) Rajesh Kumar; Ram Singh
    Present investigation on “Evaluation of entomopathogenic nematodes against Plutella xylostella (L.) on cabbage” was carried out in laboratory and screen-house. The investigation focused on the selection of appropriate indigenous strain of EPN, its application as foliar spray and its compatibility with currently used insecticides and Bt against Plutella xylostella on cabbage. EPN isolates (Steinernema asiaticum, Steinernema sp. RB-5 and Heterorhabditis bacteriophora) were used to know the effectiveness against P. xylostella. Third instar larvae of P. xylostella were susceptible to all three EPNs isolates. Steinernema sp. (RB-5) was least virulent (larval mortality 15.62%) after 96h whereas highest virulence was observed in S. asiaticum (larval mortality 65.62%) at 20±1ºC. Nematode multiplication (no. of IJs recovered per larva) was recorded highest (1226) in S. asiaticum. On the basis of highest mortality and maximum nematode multiplication S. asiaticum was selected for further studies on its pathogenic potential, compatibility with insecticides, effect of temperature on its growth and development, and its efficacy against P. xylostella as foliar spray. LC50 value of S. asiaticum was worked out to be 11.2 by using Probit analysis. At 20 and 25 ˚C, S. asiaticum caused 45 and 80 per cent mortality after 96 h. S. asiaticum caused significant insect mortality even at the high temperatures. S. asiaticum was effective within 20-35 °C, with optimum insect mortality at 30 °C. Nematode multiplication was maximum at 30 °C. Maximum IJs recovery was at 30 (279) and 35˚C (228). Maximum nematode growth and development took place at 35 °C. S. asiaticum was compatible with endosulfan, malathion and Bt and it can be incorporated in the IPM programme for management of P. xylostella. Split application (15000 + 15000 IJs) of S. asiaticum IJs proved better and resulted in 48.33 per cent mortality as compared to single dose (30,000) that caused 36 per cent mortality.