Genetic Architecture of Green Fruit Yield and Related Traits in Elite Selections from Multi-Parent Derived Chilli Populations Based on Skewness and Kurtosis
Abstract
Understanding the genetic architecture of yield and its component traits is essential for developing effective selection strategies in chilli (Capsicum annuum L.). Multi-parent (MP)-derived populations provide opportunities for generating broad genetic variability through the recombination of alleles from several founder parents. The present investigation was undertaken to characterise the frequency distribution and infer the nature of gene action governing yield and yield-related traits in elite selections derived from superior eight-parent MP populations. Five superior MP-derived populations, D4 × D3, D4 × D2, D5 × D2, D6 × D2 and D7 × D2, identified in an earlier assessment of ten MP-derived populations, were used. Observations were recorded for average fruit weight, average fruit number plant⁻¹, average fruit length, average fruit width and green fruit yield plant⁻¹. Skewness and kurtosis coefficients were estimated to assess the nature of the distribution and infer the possible genetic control of the traits. Most traits exhibited relatively low-magnitude skewness, indicating near-symmetrical distributions, although the direction of skewness varied among populations and traits. Negative skewness was predominant for average fruit weight, particularly in D4 × D3, D4 × D2, D5 × D2 and D6 × D2, suggesting duplicate-type digenic epistasis involving increasing effects. In contrast, positive skewness predominated for fruit number and green fruit yield, indicating complementary-type epistasis involving decreasing effects. Most trait-population combinations showed platykurtic distributions, suggesting the involvement of a relatively large number of genes. However, fruit width in D5 × D2 and fruit length in D6 × D2 showed leptokurtic distributions, indicating relatively fewer genes contributing to phenotypic variation for these traits in those populations. The results demonstrate that the genetic architecture of yield and its component traits varies among MP-derived populations and highlight the value of elite MP-derived progenies as sources of useful genetic variation for chilli improvement.