Shailesh Pandey

Genomics and molecular breeding in lesser explored pulse crops: current trends and future opportunities.

Pulses are multipurpose crops for providing income, employment and food security in the underprivileged regions, notably the FAO-defined low-income food-deficit countries. Owing to their intrinsic ability to endure environmental adversities and the least input/management requirements, these crops remain central to subsistence farming. Given their pivotal role in rain-fed agriculture, substantial research has been invested to boost the productivity of these pulse crops. To this end, genomic tools and technologies have appeared as the compelling supplement to the conventional breeding. However, the progress in minor pulse crops including dry beans (Vigna spp.), lupins, lablab, lathyrus and vetches has remained unsatisfactory, hence these crops are often labeled as low profile or lesser researched. Nevertheless, recent scientific and technological breakthroughs particularly the next generation sequencing (NGS) are radically transforming the scenario of genomics and molecular breeding in these minor crops. NGS techniques have allowed de novo assembly of whole genomes in these orphan crops. Moreover, the availability of a reference genome sequence would promote re-sequencing of diverse genotypes to unlock allelic diversity at a genome-wide scale. In parallel, NGS has offered high-resolution genetic maps or more precisely, a robust genetic framework to implement whole-genome strategies for crop improvement. As has already been demonstrated in lupin, sequencing-based genotyping of the representative sample provided access to a number of functionally-relevant markers that could be deployed straight away in crop breeding programs. This article attempts to outline the recent progress made in genomics of these lesser explored pulse crops, and examines the prospects of genomics assisted integrated breeding to enhance and stabilize crop yields.

Investigating Disease Controlling Ability of Brassica Volatiles and Their Compatibility with Trichoderma harzianum

The present investigation aimed to test the in vitro toxicity of Brassica volatiles against soil-borne plant pathogens (Rhizoctonia solani Kuhn, Sclerotium rolfsii Sacc., Fusarium oxysporum f.sp. ciceris (Padwick) Matuo & K. Sato and Sclerotinia sclerotiorum (Lib.) de Bary) and biocontrol fungus Trichoderma harzianum Rifai. Moreover, the response of T. harzianum to toxic volatiles was also studied in terms of glucanase and chitinase gene expression. A strong fungistatic effect of B. alba treatment was recorded against all the test pathogens. Noticeably, S. sclerotiorum manifested least sensitivity among all the tested pathogens. All T. harzianum isolates were less sensitive as compared to the assayed pathogens. Based on the in vitro study involving 6 T. harzianum isolates, T55 and Th-R showed least, while T39 showed highest sensitivity to the volatiles. Interestingly, the patterns relating to the effect of volatiles on inoculum density of T. harzianum isolates were similar to their effect on fungus growth in vitro. More importantly, expression of chitinase and glucanase genes in different Trichoderma isolates was up-regulated, which could improve the biocontrol activity of T. harzianum. Therefore, here the authors envisage that combining biocontrol and biofumigation has the potential to provide sustainable and cost-effective strategies to manage soil-borne plant pathogens.

Performance evaluation of isoproturon-degrading indigenous bacterial isolates in soil microcosm

ABSTRACT Isoproturon (IPU)-degrading soil bacteria were isolated from herbicide-applied wheat fields. These isolates were identified using cultural, morphological, biochemical and 16S rRNA sequencing methods. 16S rRNA sequences of both the bacterial isolates were compared with NCBI GenBank data base and identified as Bacillus pumilus and Pseudoxanthomonas sp. A soil microcosm study was carried out for 40 days in six different treatments. Experimental results revealed maximum 95.98% IPU degradation in treatment 6 where bacterial consortia were augmented in natural soil, followed by 91.53% in treatment 5 enriched with organic manure as an additional carbon source. However, only 14.03% IPU was degraded in treatment 1 (control) after 40 days. In treatments (2–4), 75.59%, 70.92% and 77.32% IPU degradation was recorded, respectively. IPU degradation in all the treatments varied significantly over the control. 4-Isopropylaniline was detected as IPU degradation by-product in the medium. The study confirmed that B. pumilus and Pseudoxanthomonas sp. performed effectively in soil microcosms and could be employed profitably for field-scale bioremediation experiments.