Environmental influence on reproductive traits of buffel grass facultative apomictic genotypes and its implication in plant breeding

Abstract

Cenchrus ciliaris L., a perennial C4 grass, is one of the most widely used forage species in warm and dry regions worldwide. The widespread use of the cultivar Texas raises concerns about genetic homogeneity and vulnerability. Hybridizations among facultative individuals could widen the genic pool. Therefore, a reproductive characterization of available genotypes is required. The objective of this study was to determine the reproductive mode, potential sexual expressivity, and seed fertility of four facultative apomictic genotypes throughout the flowering season, considering the influence of bioclimatic variables. We assessed the reproductive mode and potential sexual expressivity using the pistil clearing technique and seed fertility based on the production of seeds per panicle under open pollination and self-pollination. All the assessed genotypes behaved mainly as out-crossers throughout the flowering season and showed the highest potential sexual expressivity at the beginning of flowering. We confirmed the environmental influence on reproductive traits. At the beginning of the flowering season, the facultative apomictic genotypes exhibited the highest potential as female parent for hybridizations programs.