Morphological and molecular characterization of italian ryegrass populations

Abstract

Italian ryegrass is the most important temperate grass in Rio Grande do Sul, Brazil. Despite its overall importance, there are no breeding programs for this species in this State. The purpose of this study was to evaluate the existing variability within and between four Italian ryegrass populations, three from Rio Grande do Sul, Brazil, and one from Uruguay. The populations were characterized based on morphological traits such as: number of tillers, canopy diameter, heading date, total leaf area, number of leaves, area/leaf, leaf dry matter, stem dry matter, leaf/stem ratio and dry matter yield. Molecular variation was also characterized using RAPD markers. A large variability was found within the populations (98.41%), which limited the complete separation of populations. However, significant differences were found among populations for traits of great forage interest, such as the number of tillers, canopy and heading date, indicating that the present variability is suitable for the initiation of a breeding program.