Análisis morfológico de la diversidad del pasto navajita [Bouteloua gracilis (Willd. ex Kunth) Lag. ex Steud.], en Chihuahua, México

Abstract

An efficient morphologic characterization of plants includes evaluation of forage traits. The objective was to analyze morphologic diversity in native populations of blue grama grass [Bouteloua gracilis (Willd. ex Kunth) Lag. ex Steud.] in Chihuahua. In 2006, 173 ecotypes were collected in Chihuahua and transplanted in La Campana Experimental Site. Ecotypes were evaluated through morphological traits and their population structure was defined. Principal component and cluster analysis were used for data analysis. The three first principal components explained 57.3 % of total variation. The PC1, PC2 and PC3 explained 35.3 %, 12.4 % and 9.52 % of the global variation, respectively. Most important variables for PC1 were forage yield, stem density, and plant height, for PC2 were spikelet width, inflorescence length and spikelet number, and for PC3, stem diameter, leaf width and spikelet length. The PC1 included variables related to growth capacity. The PC2 grouped variables associated to propagation and dispersion. The PC3 included variables related to biomass accumulation. Also, four groups were obtained from the 145 established ecotypes. Groups 1, II, III, and IV included 59, 24, 19, and 43 ecotypes, respectively. A high morphological diversity was observed and ecotypes with high forage potential were detected according to their morphological trails. Genetic variability in blue grama grass from Chihuahua is readily available and specimens having excellent forage characteristics could be used in range improvements programs.