Genetic analysis of photosynthesis‐related traits in faba bean (Vicia faba) for crop improvement

Increasing productivity through improvement of photosynthesis in faba bean breeding programmes requires understanding of the genetic control of photosynthesis-related traits. Hence, we investigated the gene action of leaf area, gas exchange traits, canopy temperature, chlorophyll content, chlorophyll fluorescence parameters and biomass. We chose inbred lines derived from cultivars 'Aurora' (Sweden) and 'Melodie' (France) along with an Andean accession, ILB 938, crossed them (Aurora/2 x Melodie/2, ILB 938/2 x Aurora/2 and Melodie/2 x ILB 938/2), and prepared the six standard generations for quantitative analysis (P-1, P-2, F-1, F-2, B-1, and B-2). Gene action was complex for each trait, involving additive and dominance gene actions and interactions. Additive gene action was important for SPAD, photosynthetic rate, stomatal conductance and F-v/F-m. Dominance effect was important for biomass production. It is suggested that breeders selecting for productivity can maximize genetic gain by selecting early generations for canopy temperature, SPAD and F-v/F-m, then later generations for biomass. The information on genetics of various contributing traits of photosynthesis will assist plant breeders in choosing an appropriate breeding strategy for enhancing productivity in faba bean.