PEG胁迫对红丁香种子萌发及幼苗生长的影响

Effects of PEG on Syringa villosa Vahl seed germination and seedling growth

采用聚乙二醇(PEG-6000)模拟干旱,研究干旱胁迫对红丁香种子萌发及幼苗生长的影响。结果表明,红丁香种子发芽率、发芽势、发芽指数和活力指数,在2.5%的处理时分别为54.44%、27.78%、13.11和0.72,之后,随着PEG浓度增加逐渐下降;随着胁迫程度的增加,PEG对红丁香种子幼苗生长的抑制作用增强,在2.5%胁迫时红丁香种子的胚根、胚芽、鲜重及干重最大,分别为2.97cm、1.48cm、48.27mg和2.37mg;与对照组相比,红丁香种子的胁迫指数与抗旱指数随着PEG浓度的增加逐渐下降,在2.5%时最大,分别为0.97、1.62;红丁香种子的PEG半致死浓度为10.0%,从抗旱等级来看,红丁香种子能耐10.0%浓度的干旱胁迫。

Effects of drought stress simulated by polyethylene glycol （P E G -6000） O n Syrin-ga villosa Vahl seed germination and seeding growth were analyzed. The results showed that the germination rate,germination trend, germination index,and vitality index of the seeds gradually were 54. 44%,27. 78%, 13. 11 and 0. 72 respectively under the stress of 2. 5 % PEG -6000 solution, reaching its highest. With the increase of P E G stress, the inhibition effect on the seedling growth of Syringa villosa Vahl also increased. Under the 2. 5 % PEG -6000 solution,the radicel length,plumule length,fresh weight and dry weightof the seeds reached the m a x i m u m,which were 2. 97 c m, 1. 48 c m,48. 27 m g and 2. 37 m g respectively. Compared with the control group （C K ）, the stress index and drouance index of lilac seeds gradually decreased with the increase of PEG conhighest value of which were 0. 97 and 1. 62 respectively at 2. 5 % solution of PEG . The semi -lethal PEG for the Syringa villosa Vahl seed was 10. 0 %,and the drought stress of 10. 0% was the maximum drought resistance level for the seed.