聚乙二醇对羊茅属4种植物种子萌发特性的影响研究

Effect of polyethylene glycol (PEG) on seed germination characteristics of four species of Festuca

用不同浓度聚乙二醇（PEG）溶液作为渗透胁迫剂,对羊茅属Festuca4种牧草种子的萌发情况进行了研究。结果表明,低PEG浓度（5%）促进中华羊茅F.sinensis和西北羊茅F.kryloviana胚根的生长,较高PEG浓度（10%～15%）显著抑制4种羊茅植物胚根和胚芽的生长及种子发芽率、发芽势、发芽指数和活力指数的提高,PEG浓度对胚芽生长的抑制效应比胚根大。各植物胚根（芽）长、发芽率、发芽势、发芽指数和活力指数均随PEG浓度的增加呈显著降低变化（P〈0.05）。胚根/胚芽比、发芽率、发芽势可作为羊茅属牧草种子萌发期抗旱性初步评定的鉴定指标。4种植物的抗旱性顺序为中华羊茅〉西北羊茅〉毛稃羊茅F.kirilovii和法恩苇状羊茅F.arundincea。

Seed germination of four species of Festuca under different concentrations of polyethylene glycol（PEG） solution was conducted in this study. The results indicated that the lower PEG （5%） concentration promoted the radicle growth of F. sinensis and F. kryloviana, the higher PEG concentration （10%-15%） inhibited significantly the growth of radicles, plumules, seed germination rate, germination energy, germination index and vigor indexes of this four species. PEG concentration treatments had a larger inhibiting effect on plumule growth than that on radicle. The length of radicle or plumule, germination rate, germination energy, germination index and vigor index of each species decreased significantly with increased PEG concentration （P〈0. 05）. The ratio of radicle length to plumule length, germination rate and germination energy could be looked on as drought-resistance indices. The drought-resistance order of four species was F. sinensis 〉F. kryloviana 〉 F. kirilovii and F. arundincea.