Analyzing genetic variation and graphical representation (Wr-Vr) in Brinjal (Solanum melongena L.) using the hayman approach in the northwestern region of India

Brinjal, also known as eggplant, is a resilient and widely cultivated vegetable crop in the Solanaceae family. It plays a crucial role in diets due to its rich supply of vitamins, minerals and dietary fiber, helping address the deficit in vegetable consumption recommended by the World Health Organization (WHO), which advises a daily intake of at least 400 grams of fruits and vegetables. Estimating genetic parameters is essential for understanding the genetic architecture of yield and its determining factors. Hayman’s diallel cross analysis method is extensively utilized in plant breeding due to its capacity to provide comprehensive insights into diverse genetic parameters, including gene action, degree of dominance and heritability.

Nine parents with thirty six F₁ hybrids of brinjal derived using a half diallel mating design with nine brinjal genotypes, namely JBL-1, JBR-1, JBR-2, JBR-3, JBL-2, JBL-3, JBR-4, JBR-5 and JBR-6 were evaluated for yield and other yield attributing traits during kharif season 2023) using randomized block design (RBD) with three replications.

The dominance effect (H₁) was significant and displayed a greater magnitude, indicating dominance gene action for yield per plant. The regression coefficient slope showed a significant deviation from zero, but not from unity, indicating the absence of non-allelic interaction. Furthermore, the regression line intersected the Wr axis below the origin, suggesting the presence of overdominance for days to 50% flowering, fruit length (cm), number of primary branches per plant, plant height (cm), total fruit yield per plant (kg) and fruit borer infestation (%). The mean degree of dominance exceeding one indicated the prevalence of over-dominance for all traits except days to first picking, average fruit weight (gm), fruit girth (cm) and number of fruits per plant. These findings emphasize the importance of dominance variation in eggplant improvement, enabling successful heterosis breeding for advancing these populations and development of hybrids.