Capsaicinoid Inheritance in an Interspecific Hybridization of Capsicum annuum × C. chinense

Abstract

Pungency, caused by the presence of capsaicinoids, is a major quality-determining factor in chile ( Capsicum L. sp.) The inheritance of nordihydrocapsaicin, capsaicin, dihydrocapsaicin, isomer of dihydrocapsaicin, and homodihydrocapsaicin has not yet been determined. Generations mean analysis revealed that additive, dominance, and interaction effects were significant for capsaicin, dihydrocapsaicin, and isomer of dihydrocapsaicin in an interspecific hybridization of C. annuum L. × C. chinense Jacq. A simple additive-dominance model was sufficient to explain the genetic variation for nordihydrocapsaicin and homodihydrocapsaicin. Except dihydrocapsaicin and isomer of dihydrocapsaicin in the BCP 1 family, the values of backcross families shift toward the recurrent parents. Because of the significant additive gene effect and the tendency of the values of the capsaicinoids at backcross families to shift toward the recurrent parents, repeated backcrossing and selection will increase and decrease (depending on the recurrent parent) the capsaicinoid content. Positive genetic correlations were observed between the capsaicinoids and the values ranged from 0.4 to 0.8. The estimated number of effective factors were 0.4 for nordihydrocapsaicin, 0.6 for homodihydrocapsaicin, 0.9 for isomer of dihydrocapsaicin, 1.1 for dihydrocapsaicin, 2.8 for total capsaicinoids, and 6.2 for capsaicin. Different gene actions and a different number of effective factors involved in the capsaicinoids inheritance imply that different genes are controlling the synthesis of each capsaicinoid.