The Role of Yield Components in Pea (Pisum sativum L.) Yield Adaptability.

Yield variation across environments is closely related to the response of individual yield components to environmental conditions. In this study, nine pea (Pisum sativum L.) breeding lines were evaluated over four growing seasons at the site where they were selected. Seed productivity per plant, number of pods per plant, number of seeds per pod, and thousand-seed weight were measured at the individual plant level. Linear mixed-effects models were used to estimate the effects of genotype, year, and genotype × year interaction on seed productivity per plant and to assess whether the relationships between yield components and this trait changed between growing seasons. A significant genotype × year interaction indicated that genotypes responded differently across growing seasons. Pod number showed the strongest association with seed productivity per plant and the largest standardized effect. In contrast, the interaction between year and thousand-seed weight was not significant, indicating a relatively consistent relationship with seed productivity across growing seasons. These results show that the relationships between individual yield components and seed productivity changed across growing seasons. Identifying the importance of yield components under varying environmental conditions provides useful phenotypic information for understanding yield stability and adaptive responses to interannual environmental variation and may contribute to breeding for improved performance under growing conditions.