Assessment of Genetic Variability and Traits Association in Pigeonpea [Cajanus cajan (L.) Millsp.] Germplasm

Background: Pigeon pea is an important dietary protein source for humans but the production was constrained by various biotic and abiotic factors. Breeding strategies were followed to improve yield and developing high yielding varieties but at the same time utilization of genetic resources have declined. Pigeon pea is native to India with huge natural genetic variability in the local germplasm and its wild relatives. So it is necessary to identify and select breeding material from germplasm with considerable genetic and morphological variability to utilize in breeding programmes. As an initial study, 200 pre-breeding lines developed were evaluated for morphological variability patterns.Methods: A total of two hundred lines selected from F4 generation of pigeon pea developed at ICAR-NBPGR were evaluated in randomized block design (RBD) during 2014-2015 kharif season under Indo-Swiss collaboration in Biotechnology at Agricultural College and Research Institute, Madurai (TNAU). The accessions found to be superior in seed yield than the local check APK1 were forwarded to the next generation (2015-2016) for assessment of genetic variability, heritability, genetic advance and association studies.Result: Qualitative traits were evaluated and variation in leaflet shape, stem colour, pattern of streaks and base seed colour were observed. All tested lines expressed greater variability for most of the traits. Maximum coefficient of variation was observed for number of pods per plant followed by number of primary branches per plant. Selection of traits with moderate heritability coupled with high genetic advance like number of pods per plant, number of primary branches per plant could help in crop improvement program. Seed yield was positively correlated with number of seeds per pod, number of pods per plant and hundred seed weight. Potential genetic stocks and donors for high yield were selected based on hundred seed weight and seeds per pod. The accessions superior in number of pods and seed yield than check were forwarded to next generation for assessment. The identified trait-specific accessions will help in future breeding program.