Development of an effective plant growth promoting rhizobacteria (PGPR) inoculant necessitates the presence of a diverse set of traits that can help its colonization of the rhizosphere and survival under varying environmental conditions. In our investigation, a set of 100 bacterial isolates from the rhizosphere of wheat plants were screened initially on the basis of a seed germination assay; ten bacterial isolates (AW1-AW10) were selected. These isolates were then tested in vitro for specific PGPR traits, such as the production of IAA, siderophore, ammonia, HCN, P solubilization, ACC deaminase activity, acetylene reduction assay and antifungal activity. Of the ten isolates, AW5 was found to be promising for all PGP attributes. An experiment undertaken in the controlled conditions of the National Phytotron Facility revealed the potential of three isolates (AW1, AW5 and AW7) in enhancing the growth parameters of wheat plants. Characterization of these isolates using polyphasic approaches involving both phenotypic and genotypic attributes led to their identification as Bacillus sp. (AW1), Providencia sp. (AW5), and Brevundimonas diminuta (AW7), respectively. These strains could prove effective PGPR inoculants as they possess a number of traits useful for their establishment and proliferation in soil. The genus Providencia is reported for the first time for its PGP potential, using cultural as well as functional attributes to show its suitability as an inoculant for wheat crop.

β-glucosidase is a crucial element of the microbial cellulose multienzyme complex since it is responsible for the regulation of the entire cellulose hydrolysis process. Therefore, the aim of the present work was to explore the diversity and distribution of glycosyl hydrolase family 1 β-glucosidase genes in three different environmental niches including, Himalayan soil, cow dung and compost by metagenomic approach. Preliminary evaluation through metabolic profiling using BIOLOG based utilization patterns of carbon, nitrogen, phosphorus and sulfur revealed the environment and substrate specific nature of the indigenous microbial population. Furthermore, clonal library selection, screening and sequence analysis revealed that most of the GH1 β-glucosidase proteins had low identities with the available database. Analysis of the distribution of GH1 β-glucosidase gene fragments and β-glucosidase producing microbial community revealed the environment specific nature. The OTUs obtained from Himalayan soil and compost metagenomic libraries were grouped into 19 different genera comprising 6 groups. The cow dung sample displayed the least diversity of GH1 β-glucosidase sequences, with only 14 genera, distributed among three groups- Bacteroidetes, Firmicutes, and Actinobacteria. The metagenomic study coupled with metabolic profiling of GH1 β-glucosidase illustrated the existence of intricate relationship between the geochemical environmental factors and inherent microbial community.

The effect of topical application of Artemisia annua oil on the development and reproduction of Dysdercus koenigii was studied. On the basis of 48 h mortality, the LD50 for fifth instar nymphs was 0.48 μl/nymph. The treated nymphs showed 2 days delay in development, and also produced intermediates. The treatment decreased haemolymph protein concentration and disturbed its electrophoretic protein pattern. The adults which emerged from treated nymphs showed poor ovary development. There was a greater median neurosecretory activity in the treated insects compared with control insects till day 6 of adult life.

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