GENETIC EFFECTS AND HETEROSIS OF SHELF LIFE IN SERRANO HOT PEPPER

Abstract

The knowledge of expression of the genetic factors for postharvest quality is useful for plant breeding. In this research we estimated the genetic effects for the shelf-life duration of serrano hot pepper (Capsicum annuum L.), and characterized several cultivars for this trait. The diallel crosses and their seven parental lines were evaluated under field conditions in Tamaulipas, during the Fall-Winter 2001 season. The measured traits were fresh fruit, yield of shelf-life (days to loss of marketing value), individual fruit weight and rate of fruit weight loss. Results showed that yield expression is determined by both additive and dominant gene effects, while the shelflife and individual fruit weight are only determined by genetic effects of dominance; the rate of fruit weight loss are determined only by additive genetic effects. High heterotic effects were observed for shelflife and individual fruit weight, while for yield they varied from low to moderate values. The heterosis ranged from 11 to 127 % for fresh fruit yield; from 0.5 to 248 % for shelf-life; from 17 to 247 % for individual fruit weight; and from -37 to 52 % for the rate of fruit weight loss. There were significant effects (P ≤ 0.05) of general combining ability for yield and rate of weight loss, and also in the specific combining ability for yield. Therefore, the shelf-life and individual fruit weight should be bred by methods exploiting the genetic dominance effects to produce hybrid varieties, whereas for fruit weight loss breeding is best by inbreeding and selection methods.