Estimation of Heterosis and Heterobeltiosis in Experimental Bell Pepper Hybrids (Capsicum annuum L.)
Background: Bell pepper (Capsicum annuum L.) breeding can exploit heterosis and heterobeltiosis to identify parental combinations with improved agronomic and fruit-quality performance. Aims: The objective was to develop and evaluate experimental bell pepper hybrids produced through single plant-to-plant crosses in order to estimate their heterosis and heterobeltiosis. Study Design: A randomised complete block design was used, comprising sixteen treatments with three replications each; heterosis and heterobeltiosis were estimated using the corresponding formulas. Place and Duration of Study: Experimental greenhouse "The Bajío", Buenavista, Department of Horticulture, Universidad Autónoma Agraria Antonio Narro, from February 2024 to November 2025. Methodology: Bell pepper experimental lines in the fifth filial generation (F5)—identified as L1, L6, L9, and L11—were used for crosses. Twelve hybrids, along with the four parents, were generated and evaluated in a greenhouse by quantifying and determining morphological variables, yield, and fruit quality. Results: Regarding yield, the L9×L1 cross exhibited the highest heterosis and heterobeltiosis values (19.98% and 30.06%, respectively). For the number of fruits per plant, the L9×L1 cross showed the highest heterosis and heterobeltiosis values (21.10 and 3.55, respectively). Regarding average fruit weight, the L6×L9 cross showed heterosis of 23.42 and heterobeltiosis of 55.12. For fruit diameter, the L9×L11 cross achieved the highest heterosis value (12.77) and the highest heterobeltiosis value (17.85); in contrast, for fruit length, the cross with the highest heterosis and heterobeltiosis values was L11×L6 (11.48 and 25.03, respectively). Conclusions: Genetic divergence exists among the studied populations, as evidenced by the high heterosis and heterobeltiosis values; furthermore, maternal effects significantly influenced the variables under study, indicating the optimal direction for the cross. Consequently, these findings suggest significant variability for developing materials with high productive potential.