Genetic Variability Character Association and Heritability of Advanced Breeding Lines of Groundnut (Arachis hypogaea L.)

Groundnut is considered as an important cash crop especially among the poor communities in dry and intermediate zones of Sri Lanka. Crop improvement of groundnut is predominantly done using conventional breeding technologies. Therefore, understanding the genetic variability, heritability and other genetic parameters of existing genetic resources are highly useful in improving the breeding program. The genetic variability, character association and heritability of 18 groundnut genotypes which mostly consisted of advanced breeding lines developed at Grain Legumes and Oil Crops Research and Development Center, Angunakolapelessa (GLORDC) were studied during 2022/23 Maha season. The experiment was layout in RCBD design with 3 replicates and qualitative and quantitative parameters were recorded according to groundnut descriptor. Significant differences were observed in characters other than leaf length and number of pods per plant. PCV and GCV magnitude was moderate for height of main stem (PCV 19.57, GCV 15.49), plant width or spread (PCV 15.22 GCV 11.87), seed length (PCV 18.88 GCV 14.34) and pod length (PCV 13.01 GCV 11.80). High heritability was observed for main stem height (RD62.60 GA25.24), pod length (RD82.21 GA 22.04) and 100 seed weight (RD81.33 GA 35.52) with high Genetic advance. These traits are mainly controlled by additive gene action and are shown to be responsive to further improvement. Yield was observed to have a positive and highly significant correlation with pod weight per plant (0.646**). 100 seed weight was observed to have a positive and highly significant correlation with seed length (0.637**) and seed width (0.729**). These correlation indices can be used as indirect selection criteria in generation advancements. Overall, sufficient variability was observed in the breeding lines observed and selections based on traits of interest need to be carried out in order to advance such promising lines in the pipe line.