Evaluation of the effect of genotype-by-environment interaction on capsaicinoid production in hot pepper hybrids (Capsicum chinense Jacq.) under controlled environment

Hot pepper cultivars developed for capsaicinoid production may not perform the same in different growing environments causing a problem to control a quality product for food and pharmaceutical industries. The aim of this study was to investigate the effect of genotype-by-environment interaction on capsaicinoid production of hot pepper hybrids (C. chinense) under controlled environment. Across six growing environments under protected cultivation, seven hot pepper hybrid cultivars and two commercial cultivars were evaluated for capsaicinoid production. The results showed significant differences among cultivars, environments, and cultivar-by-environment interactions for all characteristics studied. A large proportion of variation on fruit number (80.1%), dry fruit yield (78.1%) and capsaicinoid yield (67.7%) was contributed from environment while variations due to genotype were 42.4% for capsaicinoid content trait. Higher relative humidity and lower light intensity gave higher capsaicinoid production. Phet Mordindang had high dry fruit yield, capsaicinoid content and capsaicinoid yield, however it was very sensitive to environmental changes, and therefore best for specific location adaptation. Variation in capsaicinoid production in high pungent hot pepper cultivars can be exploited by selecting hot pepper hybrids with high pungency for growing in a suitable environment or a controlled environment.