Germination patterns of species of the genus Trichloris in arid and semiarid environments

Abstract

Trichloris is an American genus with two species: T. crinita (Lag.) Parodi and T. pluriflora E. Fourn. Both species are perennial warm season grasses and valued as forage. The objective of our study was to determine the effect of different temperatures, seed weight and maternal effect (i.e., the contribution of the female parent to the offspring phenotype) on the germination pattern in populations of Trichloris species from Argentina. The optimal germination temperature for T. crinita ranged from 28 to 35°C, whereas for T. pluriflora it was near 28°C. In all temperature treatments, the seeds of T. crinita populations showed higher values of germination than those of T. pluriflora. Differences in seed weight were significant only among populations and there was a positive correlation between germination and seed weight at suboptimal temperatures. These germination patterns may explain the different distribution of species. There was no maternal effect on germination behaviour. Populations with higher seed weight would be valuable if incorporated into breeding programmes.