Correlation and path analysis of spine gourd germplasm in Bundelkhand region of Central India

This research examines the connections among fifteen morphological, physiological, and yield-related traits in spine gourd using correlation and path coefficient analysis to develop effective selection criteria for high-yielding plant varieties. The correlation analysis indicated that while vegetative characteristics typically exhibited weak links to reproductive success, certain significant correlations were identified: fruit diameter had a strong positive correlation with single fruit weight (r = 0.613), and the number of fruits per plant was positively correlated with plant height (r = 0.369). Importantly, a trade-off was noted between single fruit weight and total soluble sugar (TSS) (r = -0.420), implying that excessive biomass could impede sugar accumulation. The path coefficient analysis further dissected these correlations to pinpoint key yield determinants. Stems per plant demonstrated the highest positive direct effect (0.620) on yield, marking it as a vital selection criterion. In contrast, plant height was recognized as a "master mediator"; although it had a minimal direct effect, it exerted the most substantial positive indirect influence on traits such as SPAD values (1.082) and fruit diameter (1.079). The negative direct effect of fruits per plant underscored a source-sink limitation, where an increase in fruit load without adequate plant height leads to competition for resources. These results indicate that breeding initiatives for spine gourd should focus on stems per plant and plant height as foundational elements to enhance the expression of yield-enhancing traits.