CHARACTERIZATION OF SIDEOATS GRAMA (Bouteloua curtipendula) POPULATIONS FROM MEXICO TO SELECT GENOTYPES WITH POTENTIAL FOR SEED PRODUCTION

Abstract

The shortage of forage grasses seed in Northern Mexico is a constraint to undertake grasslands restoration programs. Thus, it is important to consider the diversity and to evaluate the seed production potential of some native and apomictic species such as sideoats gramma grass [Boutelous curtipendula (Michx.) Torr.] in natural populations. The aim of this study was to characterize the inflorescence morphological diversity of the inflorescence of sideoats grama Mexican populations, to select genotypes with potential for seed production. One hundred-sixty four genotypes were collected in 10 Mexican states and then were established ex situ. The inflorescence morphology was evaluated at physiological maturity stage through the following descriptors: inflorescence length (INL), twigs per inflorescence (CPI), spikelets per twig (SPT), twigs length (TL), rachis length (RQL), pedicel length (PDL) and seed weight (SEW) were evaluated to characterize the inflorescence morphology at the reproductive stage. The prevailing environmental variables at the ecotype’s origin were classified into three categories (high, medium, and low) of altitude (ALT) and precipitation (PP). Data were analyzed through multivariate analysis techniques using the SAS software. Morphological variability among groups of genotypes was found. The first three principal components (PC) explained 72 % of the total observed variation. The statistics pseudo F and T² suggest the formation of four groups (R² = 0.76) with multivariate significant differences (P < 0.001) between each other. Most of the groups were associated to the values of medium category of PP and ALT. Variability and differentiation among genotypes with high potential for seed production were found, where the group GI presented the highest potential for seed production. In Mexico genetic variation of sideoats grama is available for seed production. Genotypes with the highest potential for seed production were: 1 and 7 originating from Aguascalientes, 84 from Jalisco and 508 and 512 from Chihuahua.