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采用8个PEG渗透势梯度模拟干旱胁迫,探讨了松嫩草地8种豆科牧草种子萌发期抗旱性的差异。结果表明:紫花苜蓿、扁蓿豆、兴安胡枝子、细叶胡枝子和黄花草木樨5种小粒种子的发芽率、发芽势和活力指数等指标,在溶液渗透势下降到-0.6 M Pa后迅速下降,当渗透势下降到-0.8 M Pa时,各项指标为0;而五脉山黧豆、多茎野豌豆和山野豌豆3种大粒种子则在溶液渗透势下降到-0.3M Pa时指标显著下降,下降到-0.6M Pa时下降到0。小粒种子的抗旱性明显好于大粒种子。在较低的溶液渗透势范围内,PEG有提高种子活力指数和促进幼苗生长的现象,是因为PEG对种子有引发作用,增强了种子的活性所致;PEG处理抑制胚芽生长,是幼苗调节营养分配以适应不良环境的结果。
Eight PEG osmotic gradients were used to simulate drought stress, and the differences of drought resistance among 8 leguminous species in Songnen grassland at germination stage were discussed. The results showed that the germination rate, germination energy and vigor index of alfalfa, Medicago sativa, Hedyotis, Lespedeza and Lespedeza were significantly higher than those of the control Decreased, when the osmotic potential dropped to -0.8 M Pa, the indicators for the 0; and the Wulimocang bean, Stem Pea and mountain pea three kinds of large seeds in the solution when the osmotic potential down to -0.3M Pa indicators Decreased significantly to 0 when it dropped to -0.6 M Pa. Drought resistance of small seeds was significantly better than that of large seeds. In the range of lower solution osmotic potential, PEG can increase seed vigor index and promote the growth of seedlings, because PEG can induce seeds and increase the activity of seeds. PEG treatment can inhibit the growth of germ and regulate seedling nutrition Distribution to adapt to the adverse environment results.