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采用聚乙二醇(PEG-6000)模拟干旱胁迫和盆栽控水方法,研究了干旱胁迫对3种狼尾草种子萌发及苗期生长的影响.结果表明:低浓度的PEG(5%)胁迫会提高狼尾草种子的发芽率和发芽指数,当PEG体积分数大于10%时,3种狼尾草的种子发芽率随PEG浓度的增加显著下降(P<0.05),但根冠比增加;在高浓度PEG胁迫下,小穗狼尾草种子相对发芽指数大于羽绒狼尾草和巨人狼尾草,其抗旱半致死浓度和极限浓度高于巨人狼尾草;苗期盆栽控水8d后,巨人狼尾草叶片的旱害级别高于羽绒狼尾草和小穗狼尾草,小穗狼尾草的叶片相对含水量、脯氨酸含量均高于巨人狼尾草,丙二醛含量低于巨人狼尾草.研究发现,提高苗期狼尾草叶片含水量和脯氨酸积累量有利于增强其抗旱性;小穗狼尾草的苗期抗旱性结果和种子的抗渗透胁迫表现一致,并证实其抗旱性最强.
The effects of drought stress on seed germination and seedling growth of three Pennisetum saponins seedlings were studied by PEG-6000 simulated drought stress and potted water control method.The results showed that low concentrations of PEG (5%) stress The germination percentage and germination index of Pennisetum chinensis seeds were increased. When the volume fraction of PEG was above 10%, the seed germination rate of Pennisetum chinense decreased significantly with the increase of PEG concentration (P <0.05), but the root - shoot ratio increased. Under high concentration of PEG stress, the relative germination index of Pennisetum chinense seed was higher than that of Pennisetum chinense and Pennisetum chinense, and its LD50 and its ultimate concentration were higher than that of Giant Pennisetum. The drought damage level of Pennisetum chinense was higher than that of Pennisetum chinense and Pennisetum chinense, and the relative water content and proline content of Pennisetum chinense were higher than that of Giant Pennisetum, the content of malondialdehyde In the giant Pennisetum, the study found that increasing the water content and proline accumulation of Pennisetum chingii increased seedling stage drought resistance; seedling drought resistance and seed anti-osmotic stress performance consistent , And confirmed its strongest drought resistance.