Baculoviruses were isolated from three major lepidopteran pests, Helicoverpa armigera, Spodoptera litura and Amsacta albistriga in the semi-arid tropics during natural epizootic conditions at ICRISAT fields, Patancheru, Andhra Pradesh, India. Biological, morphological and biochemical analysis identified these isolates as Nucleopolyhedroviruses (NPVs). Scanning electron microscopy of the occlusion bodies (OBs) purified from diseased larvae revealed polyhedral particles of size approximately 0.5-2.5 μm [Helicoverpa armigera Nucleopolyhedrovirus (HearNPV)], 0.9-2.92 μm [Spodoptera litura Nucleopolyhedrovirus (SpltNPV)] and 1.0-2.0 μm [Amsacta albistriga Nucleopolyhedrovirus (AmalNPV)] in diameter. Transmission electron microscopy of thin sections of OBs of the three isolates revealed up to 5-8 multiple bacilliform shaped particles packaged within a single viral envelope. The dimensions of these particles were 277.7 × 41.6 nm for HearNPV, 285.7 × 34.2 nm for SpltNPV and 228.5 × 22.8 nm for AmalNPV. Each of HearNPV and AmalNPV contained up to 6 nucleocapsids and SpltNPV contained up to 7 nucleocapsids per envelope. The estimated molecular weights of the purified OB (polyhedrin) protein of the three NPVs were 31.29-31.67 kDa. Virus yield (OBs/larva) was 5.18 ± 0.45 × 10(9) for HearNPV, 5.73 ± 0.17 × 10(9) for SpltNPV and 7.90 ± 0.54 × 10(9) for AmalNPV. The LC50 values of various NPVs against 2nd and 3rd instar larvae indicated 2.30 × 10(4) and 1.5 × 10(5) OBs/ml for HearNPV, 3.5 × 10(4) and 2.4 × 10(5) OBs/ml for SpltNPV and 5.6 × 10(4) and 3.96 × 10(5) OBs/ml for AmalNPV. The lethal time required to cause 50% mortality (LT50) for these three species were also defined. This study has shown that the NPVs infecting three major lepidopteran pests in India are multiple NPVs, and they have good potential to use as biocontrol agents against these important pests.

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Grain legumes are the major food crops grown and consumed mostly by the poor farmers as an important source of protein in the drylands of the world. The ensuing climate change has posed serious potential threats to the cultivation of these crops that are important for the sustainable livelihoods of the poorest of the poor in these regions. There is evidence to suggest that the ecological dynamics and equilibriums are likely to be affected as a result of changing climate, either by making these crops susceptible to new diseases or by increasing the intensities of diseases, pests, and parasites. Despite many uncertainties, there is a growing consensus that these adversities could lead to an overall increase in the disease and pest pressure besides harsher abiotic stresses. Since most of the grain legumes have a narrow genetic base and levels of resistance to some biotic and abiotic constraints are low, making crop improvement an overarching research-for-development challenge for maximizing the benefits that grain legumes offer to smallholder farmers. Running against the headwinds, grain legume research has been immensely benefited by applications of modern biotechnological tools and approaches that have the potential to develop solutions for destructive diseases, besides making headway against the complex problems of drought. Similarly, identifying novel genes/traits and assessing their suitability as candidate genes for genetic engineering options will be important for future breeding programs in order to achieve remarkable impacts in these grain legume crops globally. This chapter mainly provides a comprehensive picture of the different biotechnological interventions adopted for addressing various constraints in gain legume productivity and improvement, highlighting the pitfalls and possible solutions that can be taken through an integrated approach to combat the altered environmental conditions.