Executive Summary : | Grass pea is closely related to pea, and in India it is grown on 0.47 mha land (Tiwari and Shivhare, 2017). It is relatively rich in protein and can tolerate drought, excess precipitation, and flooding. These qualities make grass pea an attractive crop for poor agricultural conditions. Despite these advantages, grass pea is not widely cultivated in India because the consumption of grasspea as a staple food causes the paralytic disease called neurolathyrism in humans and domestic animals. The cause of neurolathyrism is an anti-nutritive factor, β-N-oxalyl-L-α,β-diaminopropionic acid (β-ODAP), which has neurotoxic properties. Intensive breeding efforts are required to eliminate the anti-nutritional compound ‘β-ODAP’ from the grasspea. Conventional breeding has led to the development a few low-ODAP varieties of grasspea using low-ODAP donor Ratan ‘a somclone variant of Pusa-24’. But their stability under extreme environmental conditions is a major concern as β-ODAP content is often elevated under abiotic stresses, including drought. The shortage of low-ODAP donors and absence of ‘β-ODAP’ free accessions in the grasspea germplasm or its wild relatives further hinder the development of stable, toxin-free, safe varieties of grasspea. The Research propose to use existing physical mutagens-induced mutant populations of grass pea as novel resources for the rapid identification of mutants for the low/zero-ODAP content. The low or β-ODAP free lines will be screened using the high throughput microtitre plate-based spectrophotometric assay (Emmrich et al., 2019). The toxin-free lines will be further confirmed by the highly-sensitive LCMS-based method of ODAP estimation (Emmrich et al., 2019). The identified low/zero-ODAP mutants will also be screened under drought stress conditions together with genotypes having high β-ODAP content to establish any correlation between drought tolerance and β-ODAP content. This will aid in developing grass pea with reduced levels of ODAP but higher tolerance to drought stress. Recently, the genes encoding the enzymes of β-ODAP biosynthesis pathway viz., Oxalyl-CoA synthetase (Genbank: MH469748), ODAP synthase (Genbank: MZ127248), and β-cyanoalanine synthase (Genbank: KJ563188) has been identified and characterised. These genes and other genes likely to be involved in ODAP biosynthesis or its regulation will be screened for mutations in the low-ODAP mutants by PCR and sequencing. Identifying allelic variations of these genes will help in developing molecular markers that can be used for marker assisted breeding of low/zero variety. |