PEG-6000干旱胁迫对5种牧草种子萌发的影响研究

Effects of PEG-6000 Drought Stress on Seed Germination of Five Forage Grass Species

为了解5种冷季型牧草种子萌发期的抗旱性,采用聚乙二醇(PEG-6000)模拟干旱,分别以5%、10%、15%聚乙二醇溶液作渗透介质,研究了不同干旱胁迫对紫花苜蓿、白三叶、多年生黑麦草、红三叶和细弱翦股颖等5种牧草种子的发芽率、发芽势、发芽指数、活力指数等4个指标的影响。研究结果表明:随PEG-6000浓度的增加,白三叶、紫花苜蓿、多年生黑麦草、细弱翦股颖的发芽率、发芽势、发芽指数和活力指数都呈现下降趋势;红三叶在5%的水分胁迫下发芽率、发芽势、发芽指数和活力指数均高于对照。经回归统计检验和系统聚类分析综合评价结果,该5种牧草种子抗旱性强弱依次为:细弱翦股颖>红三叶>紫花苜蓿>白三叶>多年生黑麦草。

In order to understand the seed drought resistance of five cool-season forage grass species during seed germination period, PEG-6000 at the concentration of 5%, 10% and 15% were used as the penetration media to simulate drought stress. And effects of different drought stresses on germination of different cool-season forage grass seeds（Medicago sativa L., Trifolium repens L., Lolium perenne L., Trifolium pratense,Agrostis tenuis Sibth.） were studied. Four indicators which were germination rate, germination potential,germination index and seed vitality index were measured. The results showed that germination rate,germination potential, germination index and seed vitality index of T. repens, M. sativa, L. perenne, A. tenuis all decreased with the increase of PEG-6000 concentration. The four indicators of T. pratense increased at 5%PEG-6000 concentration. Regression statistical tests and hierachical cluster analysis showed that drought resistance of the five forage grass species was in an order as A. tenuisT. pratenseM. sativaT. repensL.perenne.