Abstract:

To explore the propagation and diffusion mechanism of wild Elymus nutans in Baqin County, Tibet, and provide the necessary theoretical basis for its development and utilization, the seed germination characteristics of Elymus nutans were studied under different light, temperature, water (PEG6000) and salt treatment conditions. The results showed that the light had no significant effect on Elymus nutans seed germination; Under the conditions of constant temperature of 25℃ and alternating temperature of 20/30℃, the seed germination speed of Elymus nutans was faster and the germination percentage was higher, but the seed no germination at constant 5℃ and 35℃; Elymus nutans seed germination percentage was slightly higher than the control (CK) when PEG concentration was 5%, but the germination index and vigor index were significantly lower than the control; In the range of 0%~0.4% NaCl solution concentration, the seeds can germinate normally, and slight salt stress (0.2%) could promote the seed germination of Elymus nutans. The results showed that low temperature was the key factor that limited the successful germination of the wild Elymus nutans seeds in the area of Baqing in Tibet.

Key words: Elymus nutans, Seed germination, Temperature, Light, Water stress, Salt stress, Tibet

摘要：

本研究探索了西藏巴青县野生垂穗披碱草（Elymus nutans）种群繁殖扩散机理，为其开发利用提供必要的理论基础。试验在不同光、温、水（PEG6000）、盐处理条件下研究了垂穗披碱草种子萌发特性。结果表明：光照对垂穗披碱草种子萌发无显著影响；恒温25℃和变温20/30℃条件下垂穗披碱草种子萌发速度较快、发芽率较高，而5℃和35℃条件下种子不萌发；在PEG浓度为5%时垂穗披碱草种子发芽率略高于对照（CK），但其发芽指数和活力指数都显著低于对照（CK）；在NaCl溶液浓度为0%～0.4%范围内，种子均能正常萌发，且轻度盐胁迫（0.2%）对垂穗披碱草种子萌发有促进作用。上述结果说明，低温是限制西藏巴青地区野生垂穗披碱草种子成功萌发的关键因子。

关键词: 垂穗披碱草, 种子萌发, 温度, 光照, 水分胁迫, 盐胁迫, 西藏