盐、碱胁迫与温度对黄花苜蓿种子发芽的影响

Effects of salinity,alkalinity,temperature and their interactions on seed germination of Medicago falcata

为了探讨盐、碱胁迫与温度交互作用对黄花苜蓿(Medicago falcata)种子萌发的影响,选用两种中性盐(Na Cl、Na2SO4)和两种碱性盐(Na2CO3、Na HCO3),3个温度(10/20℃、15/25℃和25/35℃)处理,测定各因子对种子最终发芽率及发芽速度的影响。结果表明,盐、碱胁迫与温度及其交互作用对黄花苜蓿种子发芽均有显著影响(P<0.05)。黄花苜蓿种子发芽率和发芽速度在10/20℃或15/25℃处理下最高,并且两者之间差异不显著(P>0.05)。随着盐、碱胁迫浓度的增加,种子发芽率和发芽速度降低,且碱性盐的胁迫作用大于中性盐。25/35℃高温显著抑制了各个处理下黄花苜蓿种子发芽,并且加剧了盐、碱胁迫对种子萌发的抑制作用。黄花苜蓿对碱性盐和高p H有一定的耐受性,在25 mmol·L-1的Na2CO3和30 mmol·L-1的Na HCO3处理下均能良好发芽。

In the present study,the effects of salinity,alkalinity,temperature and their interactions on seed germination of Medicago falcata were evaluated by treated with two neutral salts（ Na Cl,Na2SO4）,two alkaline salts（ Na2CO3,Na HCO3）,and three alternating temperature（ 10 /20 ℃,15 /25 ℃ and 25 /35 ℃）. The results showed that seed germination percentage and germination rate were significantly affected（ P〈0. 05） by salinity,alkalinity,temperature and their interactions. The seed germination percentage and germination rate were the highest under treatments at 10 /20 ℃ or 15 /25 ℃,and there was no significant difference between them. The seed germination percentage and germination rate decreased with the increasing of salinity and alkalinity concentrations and the deleterious effect of alkali stress was more severe than salt stress. Seed germination was significantly inhibited by treatment at 25 /35 ℃ which also aggravated the inhibition of alkali and salt stress on seed germination. M. falcata had some tolerance to alkaline salts and high p H which germinated well under 25 mmol·L- 1Na2CO3 and 30 mmol·L- 1Na HCO3 treatments.