Relationship between seed germination characteristics and environmental factors of wild Bromus inermis in Xinjiang

Taking the seeds of wild Bromus inermis in Xinjiang as the research object, this study evaluated the germination rate, germination energy, root shoot ratio, germination index, vigor index, and germination mean time of the seeds under homogeneous environmental conditions and discussed the effects of habitat differences (mean average temperature, mean average precipitation, and soil nutrients) on the germination characteristics of the seeds. The results showed that 1) The seeds of B. inermis germinated after 14～16 days, and the germination rate was 50.00%～76.67%. 2) There were significant differences in seed germination characteristics among regions. Seeds in Urumuqi had the strongest germination ability, whereas seeds in Hutubi had the weakest germination ability. 3) The seeds in the habitat with high mean annual precipitation had strong germination ability. Extremely high soil conductivity and soil pH may be detrimental to seed germination and growth. 4) Wild B. inermis seeds in nine regions could be divided into three groups. The first group consisted of high germinating species with strong germination ability and high seedling uniformity; the average number of germinated seeds was 22.78. The second group consisted of intermediate species with strong germination ability and long germination duration; the average number of germinated seeds was 21.11. The third seed group consisted of the lowest germination species with weak seed germination ability, and the average number of germinated seeds was 16.22. Comprehensive comparison showed that mean average precipitation is an important environmental factor responsible for the difference in seed germination ability in different regions. The germination ability of seeds in Urumqi, Wenquan, and Balikun county was better than that of seeds in other regions. The results of this study can provide reference for the selection of high-quality B. inermis germplasm resources in Xinjiang.