Morphological structure and physiology of sideoats grama genotypes [Bouteloua curtipendula (Michx.) Torr.] in their establishment stage

The objective of this study was to characterize the morphological and physiological attributes of eight genotypes of sideoats grama. Seven native Mexican genotypes of Bouteloua curtipendula (Michx.) Torr. (Poaceae) were collected in various parts of México and compared with a commercial variety (El Reno), which was used as a control. Plants were collected at six different stages: 50, 65, 80, 95, 110, and 125 days after sowing (das). We evaluated their morphological composition, aerial part:root ratio, growth rate (GR), specific leaf area (SLA), and net assimilation rate (NAR). Data were analyzed as a completely randomized block design with five replications; means were compared with the Tukey test (P<0.05). Regarding morphological composition, significant differences were observed in all genotypes for all stages (P<0.01). Genotypes 62 and 181 collected at 125 das showed a higher stem proportion when compared to the other morphological components. Genotypes 303, 125, and 5 showed the lowest proportions in root (P<0.05). The aerial part:root ratio was higher in genotype 303 (P<0.05). The root growth rate values obtained were similar among the proposed genotypes (P>0.05); however, all proposed genotypes presented higher values than El Reno (P<0.05). Likewise, the aerial part growth ratio values obtained showed that proposed genotypes presented higher values than El Reno (P<0.05). The results presented in this study show that genotypes 303, 125, and 5 had superior forage characteristics when compared to the commercial variety El Reno. These make such genotypes suitable species to be used in livestock activity.