Estabilidad genotipo-ambiente del valor nutritivo y la producción de materia seca de 41 genotipos de raigrás ingles

Abstract

Using evaluation data at two locations in Galicia of 41 genotypes of perennial ryegrass (35 families of a breeding population, 3 wild populations and 3 controls) a study was made of the method of structuration of the genotype by location interaction. The characters considered were: dry matter yield per year (1989-1991), NIRS predicted "in vitro" organic matter digestibility, crude protein and acid detergent fibre in two cuts. An analysis of variance of these traits revealed the importance of genotype by location interactions in the total variation for dry matter yield (3 years), acid detergent fibre and "in vitro" organic matter digestibility in the cut of the 20-6-90. These interactions were characterized by means of an ascendant hierarchical clustering on the interaction effects for each genotype. A partition into 11 clusters, accounting for 79% of the inertia, was chosen. One cluster contained the 16 more stable genotypes, all of these being families of the same breeding population. A principal component analysis carried out on the means of the 16 genotypes, permitted discrimination between the genotypes with the best performance