In vitro propagation of an economically important medicinal plant Lawsonia inermis L. through nodal segments

The present investigation aimed to standardize efficient plant regeneration protocol through in vitro culture by using nodal segment for mass multiplication of Lawsonia inermis an economically important medicinal plant species. Mass multiplication of shoots induced on Murashige and Skoog (MS) medium supplemented with different growth regulators like auxins and cytokinins separately and in different combinations. The medium fortified with 6-Benzylaminopurine ( BAP) 1.0 mg/l + kinetin (KN) 1.5mg/l explained best compared to all other combinations. In vitro raised plantlets were excised and transferred in half strength MS medium supplemented with different growth regulators like Indole Butyric acid ( IBA) and naphthalene acetic acid (NAA ) (0.5-3.0 mg/l) in an experiment that gave rise to rooting. The half strength of MS medium additive with IBA in separate and in different combinations with NAA concentrations (0.5-3.0 mg/l) supported root development. The best response of rooting was obtained on half MS medium fortified with 1.0 mg/l IBA. The regenerated plantlets were successfully transplanted to pots. Regenerants were transferred to the field conditions and recorded the survival rate.. Among all the carbon sources and gelling agents used, sucrose (3%) in combination with 0.8 per cent agar-agar has proved significantly better. Multiple shoots formation with longer shoots were achieved on medium with 1.0mg/l BAP and 1.5mg/l Kn. Thus, it is possible to develop a large number of plants of L. inermis through shoot bud regeneration which can cater for the need of pharmaceutical as well as other industries.

Studies on Optimization of Growth Parameters for Mass Multiplication of Actinobacteria

Aim: To isolate, characterize and optimize the growth parameters for mass multiplication of Actinobacteria. Place and Duration of Work: The study was carried out in Department of Agricultural Microbiology, GKVK, University of Agricultural Sciences, Bangalore during 2019-20. Methodology: Actinobacterial isolates were characterized morphologically and screened for optimization of growth parameters viz., pH, temperature, salt concentration and utilization of carbon source for their mass multiplication. Results: Forty actinobacterial isolates were enumerated from rhizosphere soil of finger millet, cowpea and also from different organic manures. Color of aerial mycelium in most of the actinobacterial isolates were white, grey or cream with dry, cottony or powdery appearance. All forty isolates were Gram positive, non-acid forming and motile. During optimization of growth parameters, results showed that all the actinobacterial isolates growth was observed good at 30℃, pH 7 and 2 per cent NaCl concentration. Starch was confirmed as the best carbon source for all the actinobacterial isolates during carbon source utilization ability. Conclusion: Based on the results, it is showed that all the actinobacterial isolates enumerated were aerobic, spore-forming, Gram positive bacteria, non-acid forming and motile. Maximum growth of Actinobacterial isolates was obtained at temperature of 30℃, pH 7 and 2 per cent NaCl concentration with the ability of growing on ten different carbon sources during the optimization of nutritional and cultural characterization studies. Among the different carbon sources, starch was confirmed as the best carbon source for all the isolates during the study of carbon source utilization ability.

Parasitism potential of Diadegma argenteopilosa (Cameron) (Hymenoptera : Ichneumonidae), an internal larval parasitoid of Spodoptera litura (Fab.) (Noctuidae: Lepidoptera)

Diadegma argenteopilosa (Cameron) (Ichneumonidae: Hymenoptera) is an internal larval parasitoid of Spodoptera litura (Fab.) (Noctuidae: Lepidoptera), a notorious and polyphagus pest of pulses and vegetables in India. Attempt has been made to initiate their mass multiplication for successful biocontrol programme. Behavioral studies, food stuffs, host selection aspects plays a crucial role in mass multiplication of biocontrol agents. Therefore, present work was conducted to study the optimum host age, specificity and host density for maximum progeny production of the parasitoid under laboratory conditions and later their release in the field for the management of pest species. The parasitoid caused highest mortality in the pest larvae of second instars, 4 day old larvae were attacked most with high percent parasitism, 39.00%. Optimum density for maximum progeny production of D. argenteopilosa was 20, which generate maximum parasitism (43.00%). Host specificity by exposing the parasitoids towards different host species and analyse parasitoid preference by S. litura > Helicoverpa armigera (Hubner) > Mythimna separata Walker > Achaea janata (Linnaeus). Nutritional requirement of parasitoid was tested with different foodstuffs and found 50% honey best suited for maximum longevity 8.2 and 11.4 days for males and females respectively. The longevity ratio also female biased, 1: 1.39 (Male: Female). From the results it concludes that D. argenteopilosa fed with 50% honey solution, exposed to 3-5 day old caterpillars of S. litura at density of 20 gave maximum progeny production and effectively utilized in the biocontrol programme.