To unravel genetics of quantitative traits (QTs), most researcher’s attempts are based either on first or second degree statistics, and rarely both. Use of both first and second degree statistics provide the most comprehensive mode of action of genes controlling QTs in crop plants. Meanwhile, genetic analysis based on third and fourth degree statistics is powerful and useful in detecting and characterizing the nature of epistasis. Genetics of fruit yield and its component traits (including TSS as quality trait) was unravelled using a combination of first and second degree and also third and fourth degree statistics in muskmelon. The results based solely on first and second degree statistics were contradictory. While, first degree statistics suggested the predominance of genes with dominance effects, second degree statistics indicated the predominance of additive gene effects in controlling the inheritance of most QTs investigated. However, the combination of first and second degree statistics revealed the importance of both additive and dominance genetic effects in the inheritance of average fruit weight, TSS and fruit cavity size in the genetic background of 21KGSB-258 × 21KGSB-93. High magnitude of estimates of additive gene effects [d] and additive genetic variance (σ2A) coupled with low magnitude / non-significant dominance gene effects [h] and non-significant dominance genetic variance (σ2D) suggested high frequency of increasing effect genes controlling the inheritance of average fruit yield, average fruit weight, fruit cavity size and TSS in the genetic background of 21KGSB-218 × 21KGSB-54. Bi-parental mating in F2 generations before exercising selection is suggested to reduce dominance genetic effects to increase the effectiveness of selection for fruit weight, TSS and cavity size in the cross 21KGSB-258 × 21KGSB-93. Simple selection in F2population is expected to result in rapid genetic gains for average fruit yield, average fruit weight, fruit cavity size and TSS in the genetic background of 21KGSB-218 × 21KGSB-54.

Muskmelon, Quantitative traits, Additive effect, Additive genetic variance, Dominance effect, Dominance genetic variance

The first, second, third and fourth degree statistics based genetic models served as valuable tools and provided comprehensive and mutually complementary information on the nature and magnitude of gene action in controlling commercially important fruit traits in muskmelon.

Ranjitha G.V., A.M. Rao, Basanagouda G., Ujjal K., Nateshan H.M., Kavya M.E., Shilpa M. and Prashantha V. (2023). Genetics of Quantitative Traits in muskmelon (Cucumis melo L.). Biological Forum – An International Journal, 15(8): 378-388.