Bold-seeded and seed coat colour mutations in grass pea (lathyrus sativus l.): origin, morphology, genetic control and linkage analysis

Three different types of mutations affecting seed size and seed coat colour were detected in gamma ray induced M2 progeny of two grass pea (Lathyrus sativus L.) cultivars, ‘Nirmal’ and ‘BioR-231’. Seed size was larger in bold-seeded mutant (BSM) line than cultivars, while normal grey-brown colour of seed coat was modified to black in black seed coat mutant (BSCM) and whitish-yellow in whitish-yellow seed coat mutant (WYSCM). The BSM and BSCM exhibited high grain yield and low seed neurotoxin (ODAP) content, whereas WYSCM showed exuberance in vegetative growth and marginal reduction in seed ODAP content. Among other agronomic desirable traits, BSM manifested erect growth habit and tolerance to seed shattering at maturity. The three mutants were true breeding for their respective traits in M3 generation. Inheritance and linkage analysis revealed digenic non-allelic control of bold seed size, while seed coat colour was governed by monogenic recessive gene with involvement of multiple alleles. Both bold-seeded and seed coat colour muations were linked with each other and also with a flower colour locus, controlling blue colouration in petals of grass pea flower.