温度对两种野生禾草种子发芽的影响

采用2种恒温和6种变温8种处理方法,研究了不同温度对松嫩平原野大麦和贝加尔针茅2种野生禾草种子萌发影响。结果表明,变温有助于提高2种禾草种子发芽率。野大麦在30℃/20℃变温条件下的发芽率最高,达到53.33%。贝加尔针茅在昼夜温差为7.5～20.5℃的变温环境下发芽率最高,为25.67%。贝加尔针茅对发芽温度很敏感,而野大麦发芽适宜温度的范围较大。野大麦和贝加尔针茅种子萌发后,幼苗重量均随生长天数的增加而增加,胚乳的重量均随生长天数的增加而减少的变化趋势。幼苗重量与胚乳重量呈极显著的负相关关系。

Effects of temperature on seed germination of two species of wild grasses

The effects of different temperatures on germination capacity of two species of wild grasses　were studied on　the Songnen Plains of China. Eight temperature treatments were used included two constant temperatures and six variable temperatures. The results showed that variable temperatures resulted in improvement of the germination rates of the seeds of Hordeum　brevisubulatum and Stipa baicalensis. The germination rate　of H. brevisubulatum was the highest at the alternate temperature 20～ 30℃, which was 53.33%. The germination rate　of S.　baicalensis was the highest (25.67%) under the variable temperature with the temperature difference between day and night varying 7.5～ 20.5　℃. S.　baicalensis　was sensitive to the temperatures, while the　optimum　germination temperatures of H. brevisubulatum　varied largely. After the germination, H.　brevisubulatum　and　S.　baicalensis　showed the same pattern: The weight of endosperm decreased with the days increasing and there was significant negative correlation between the weight of seedling　and endosperm.