Distinguishing proof and utilization of resistance of insect pests in grain legumes: Progress and limitations

Abstract

Major food legumes including chickpea, pigeon pea, cowpea, field pea, lentil, faba bean, black gram, green gram, and Phaseolus beans play a vital role in food, nutritional security, and sustainable crop production. Several insect pests damage grain legumes, of which Helicoverpa armigera; Maruca vitrata; Etiella zinckenella; Spodoptera litura and S. exigua; Melanagromyza obtusa; Ophiomyia phaseoli; Aphis craccivora and Bemisia tabaci; Empoasca spp., Megalurothrips dorsalis, and Caliothrips indicus; Mylabris spp.; and Callosobruchus chinensis crusade extensive losses. Appreciable progress has been made in formulating techniques to evaluate germplasm, mapping populations, and genetically modified crops for resistance to insect pests under field and greenhouse conditions. No-choice and dual-choice cage screening techniques, detached leaf assay, and diet incorporation assays have been standardized to screen for resistance to major insect pests in grain legumes. However, some of these techniques cannot be used to screen against stem flies, pod fly, leafhoppers, thrips, and aphids. There is a need to develop methods for mass multiplication of aforesaid insects to undertake precise phenotyping for resistance to these insects. There is a necessity to identify lines with different resistance mechanisms/components of resistance for gene pyramiding to explicate cultivars with the stable source of resistance to insect pests. Prominent levels of resistance to the pod borers have been found in the wild accessions of chickpea, pigeon pea, and cowpea, which can be exploited to introgress genes to heighten the levels and diversify the basis of resistance to insect pests to build host plant resistance a viable component of pest management in grain legumes for sustainable crop production.