Genetic variability studies on horse gram [Macrotyloma uniflorum (Lam.) verdc.] landraces using agro-morphological traits

Horse gram, a neglected pulse crop, has been an integral component of subsistence farming in India and has the potential to significantly contribute to the global food basket under the regime of climate change. Besides being a nutritionally rich pulse, it also has the potential to treat a variety of ailments like kidney stones, throat infections, and fever due to the presence of phytic acid and phenolics. Under the present study, 155 horse gram accessions, including 150 accessions collected from 16 Indian states and five checks were evaluated to assess the extent of diversity using 27 morphological traits. The analysis indicated that seed color was the most diverse qualitative trait, having Shannon’s diversity index (SDI) of 0.86, followed by plant growth habit (0.50), leaf shape (0.49), and pod beak shape (0.47), whereas seed yield/plant (0.02–22.68 g), number of pods/plant (1–44), hundred seed weight (1.6–4.1 g), primary branches/plant (2.79-8.19), plant height (29.63–88.33), and days to 80% maturity (99.4–146) were the most diverse quantitative trait. The statistical analysis has shown a positive correlation of seed yield with pod length (r = 0.54), number of pods/plant (r = 0.51), and number of seeds/pod (r = 0.49), but a negative correlation with days to 80% maturity (r = -0.72) and 50% flowering (r = -0.68). The principal component analysis validated the observed correlations. The cluster analysis showed that the accessions representing North Indian states and Madhya Pradesh were superior for yield-contributing traits and were also early maturity types.