Heterosis and reciprocal effects for agronomic and fruit traits in Capsicum pepper hybrids

• Published in: Scientia horticulturae Vol. 295; p. 110821
• Main Authors: Naves, Emmanuel Rezende, Scossa, Federico, Araújo, Wagner L., Nunes-Nesi, Adriano, Fernie, Alisdair R., Zsögön, Agustin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.03.2022
• Subjects: Capsicum; Hybrid vigour; Parent-of-origin effect; Reciprocal crosses; Solanaceae; Hybrid vigour; Reciprocal crosses; Solanaceae; Capsicum; Parent-of-origin effect
• ISSN: 0304-4238; 1879-1018
• DOI: 10.1016/j.scienta.2021.110821

•Heterosis in autogamous plants is not studied extensively, but extent of phenotypic variation in F1 is similar to other cases of obligate outcrossers.•Full diallel crosses both within and between different Capsicum species allow dissection of phenotypic traits with additive and non-additive behaviour.•Non-additivity depends on the cross direction but also on the type of the cross.In the hybrids, heterosis in vegetative traits is inversely correlated with yield-related traits. The selection of pure lines followed by crosses to create superior hybrids is one of the oldest strategies in crop breeding. However, in chili peppers of the Capsicum genus hybrid breeding has lagged, in part due to a lack of detailed information about the phenotypic consequences of hybridization. Here, we performed reciprocal crosses between four inbred varieties of two species of cultivated C. chinense (cv. Habanero and Biquinho) and C. annuum var. annuum (cv. Jalapeño and cv. Cascadura Ikeda). We measured 31 phenotypic traits, including plant growth and yield, and 32 fruit size and shape parameters. We found large differences for agronomic and fruit traits between the genotypes, with significant heterosis and reciprocal effects for some of them. Heterosis for seed size has a strong influence on initial growth vigour. Fruit characteristics such as size and shape were impacted by hybridization, mainly interspecific, due to fertility problems. The restoration of fertility by pollination of hybrids with parental pollen was effective in modifying fruit size and shape, and differential effects depending on the pollen source used. Our results highlight how the adequate combination of parental genotypes and the optimal crossing direction can drive phenomena like heterosis, yield and fruit morphology.