Soil mediated local adaptation at the early-life stages of Stipa breviflora is context dependent

Aims Soil conditions are one of the most important selection pressures driving local adaptation of plants. Unfortunately, little attention has been paid to soil-mediated local adaptation in early stages of grass species. Thus, soil-mediated local adaptation in early-life stages of Stipa breviflora was investigated in this study. Methods Here, we collected seed and soil samples from 6 populations spanning almost the entire latitudinal range of S. breviflora in China. Then, the seeds of each population were sown in soils from 6 sites separately. Finally, we analyzed physicochemical and microbial properties of the 6 soils. Results Home soils significantly enhanced seed germination of population A, B and C, while not for population D, E and F. For field seedling emergence, only population E and F were observed that the seedlings planted in home soils were higher than those planted in non-home soils. However, seedling survival of population A, B, C and F planted in home soils was higher than those in non-home soils. No significant difference in seedling overwintering was observed between populations planted in home soils and those planted in non-home soils. Moreover, the structural equation modeling (SEM) suggested that soil traits indirectly affected seedling survival by mainly altering soil fungal diversity and total nitrogen concentration. Conclusions These results indicated that soil-mediated local adaptation exists in early-life stages of S. breviflora , while its strength of local adaptation varies across populations and early development stages. These findings provide new insights into the role of soil conditions in local adaption of plants.