Genetic Variability, Character Association and Genetic Diversity Studies in Lotus (Nelumbo nucifera) Germplasm

Abstract

Lotus (Nelumbo nucifera Gaertn.) is an aquatic crop with ornamental, medicinal, nutritional and cultural importance. The present investigation was conducted from February 2024 to October 2025 at the College of Horticulture, Mysuru, Karnataka, to assess genetic variability, character association and genetic divergence in lotus germplasm. Fifty germplasm collected from Karnataka, Kerala and Tamil Nadu were evaluated in a Completely Randomised Design with two replications. As only twenty-six germplasm flowered in both years, these were used for further evaluation and variability analysis. Significant differences were observed among the germplasm for all characters studied, indicating considerable variability. High genotypic and phenotypic coefficients of variation were recorded for number of flowers per plant (82.81% and 84.95%), number of coin leaves per plant (64.03% and 65.31%) and duration of flowering (49.97% and 53.11%). High heritability coupled with high genetic advance as per cent of mean was observed for number of flowers per plant (95.00% and 213.08%), duration of flowering (88.50% and 124.13%) and flower diameter (94.80% and 46.08%), indicating the predominance of additive gene action and the usefulness of direct selection. Number of flowers per plant showed a significant positive association with duration of flowering at genotypic (0.784) and phenotypic (0.720) levels, while days to bud initiation showed a negative association with flower yield (-0.597 and -0.459, respectively). Path analysis showed high positive direct effects of number of coin leaves per plant (1.013 and 1.029) and duration of flowering (0.482 and 0.474) on flower yield. Mahalanobis D² analysis grouped the germplasm into six clusters, with the maximum inter-cluster distance between Clusters V and VI (20.68), indicating wide genetic divergence. The results indicate that diverse germplasm identified in this study may be used in future breeding programmes for ornamental lotus improvement.