S. Ramesh

Simple Sequence Repeat (SSR) Marker Assay-Based Genetic Diversity among Dolichos Bean (Lablab purpureus L. Sweet) Advanced Breeding Lines Differing for Productivity per se Traits

Dolichos bean is one of the ancient crops widely distributed in Indian subcontinent, Africa, and Southeast Asia (Smartt, 1985), where it has been used as a grain legume and vegetable for more than 3500 years (Fuller, 2003). Despite its wide distribution in the tropics and range of adaptability and diversity, it remains as an important, but underutilized crop in many of these regions (Engle and Altoveros, 2000), as evidenced from limited area planted to this crop and efforts towards its genetic improvement (Ramesh and Byregowda, 2016). However, it’s utility as a vegetable and pulse (Ramesh and Byregowda, Increased and continued use of the diverse genotypes is a prerequisite for developing and diversifying the genetic base of crop cultivars. DNA markers which are crop-stage nonspecific environmental neutral, easily assayable and amenable for automation are being used to assess the diversity of germplasm accessions and/or breeding lines. DNA markers also provide information on the population structure, allelic richness, and parameters that specify diversity among the genotypes to help breeders to choose those most appropriate for use in cultivar development. Hence SSR markers were used to assess diversity at marker loci among 16 phenotypically diverse dolichos bean genotypes. In the present study, 52 of 55 SSR-based markers were polymorphic, resulting in 94.55% polymorphism. Amplification of genomic DNA segments complementary to 55 SSR primers resulted in 133 scorable alleles with an average of 2.5 alleles per SSR loci. SSR markers exhibited differential ability to discriminate 16 genotypes as indicated by the estimates of effective multiplex ratio which ranged from 1.89 to 4.73 and marker index ranged from 0.69 to 3.40. The average gene diversity in the present study is more than that reported in dolichos bean. The estimates of Shanon’s diversity index complemented those of average gene diversity. These results indicate that these SSR markers are highly informative and could be used to assess genetic diversity among the genotypes. The genotypes, HA 10-8, FPB 15 and RIL 162 share different alleles, FPB 8 and RIL 21 share similar alleles. Hence, the genotypes, HA 10-8, FPB 15 and RIL 162 could be used in crossing programme to derive genotypes with combination of desired traits. K e y w o r d s

Does Relative Performance of Determinate and Indeterminate Dolichos Bean (Lablab purpureus L. Sweet) recombinant Inbred lines (RILs) Depend on aturity Duration

The dolichos bean is an under-exploited vegetable-cum-pulse crop widely distributed in many tropical and subtropical countries (Purseglove, 1968; Kay, 1979). More than 150 documented local vernacular names of dolichos bean is a testimony of its world-wide distribution. The importance of dolichos bean as a food crop has been documented in archeo-botanical findings in India prior to 1,500 BC (Fuller, 2003). Presently, dolichos bean is grown in Africa, extending from Cameroon to Swaziland to Zimbabwe through Sudan, Ethiopia, Uganda, Kenya and Tanzania (Skerman et al., 1991). In South and Central America, East and West Indies, Bangladesh, China and India, dolichos bean is cultivated as annual crop (Whyte et al., 1953). In India, it is predominantly grown in southern districts of Karnataka state and adjoining districts of Tamil Nadu, Andhra Pradesh and Maharashtra. It is predominantly as a rainfed conditions for its fresh immature beans for use as a vegetable (Ayyangar and Nambiar 1935; Shivashankar and Kulkarni, 1989). International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 6 Number 7 (2017) pp. 527-540 Journal homepage: http://www.ijcmas.com