PEG模拟干旱胁迫对紫花苜蓿种子发芽及幼苗生长的影响

Effects of PEG Simulated Drought Stress on Seed Germination and Seedling Growth of Alfalfa

为了探究干旱胁迫对紫花苜蓿种子发芽和幼苗生长的影响,本研究以‘中苜1号’、‘敖汉’和‘中草3号’种子为材料,采用不同浓度聚乙二醇溶液进行处理,观测分析了胁迫对种子的发芽势、发芽率以及幼苗的鲜重、干重、苗长、主根长、主根粗和侧根数的影响。结果显示,5%的PEG胁迫处理即可显著抑制3个品种紫花苜蓿种子的发芽势和发芽率以及幼苗的鲜重、苗长和侧根数(p<0.05),且抑制和影响作用随着胁迫强度的增强而明显加剧,但‘中草3号’受到的影响最弱。同时,10%的PEG胁迫处理才对‘中草3号’幼苗的主根粗产生显著抑制作用,而‘中苜1号’和‘敖汉’的幼苗主根粗在5%的PEG胁迫时即被显著抑制(p<0.05)。因此,初步推断‘中草3号’的抗旱性较‘中苜1号’和‘敖汉’强,可为内蒙古地区种植紫花苜蓿品种选择提供一定的理论依据和参考价值。

In order to study the effects of drought stress on seed germination and seedling growth of alfalfa,the seeds of‘Zhongmu No.1’,‘Aohan’and‘Zhongcao No.3’were respectively treated with different concentration of polyethylene glycol(PEG).The response characteristics of seed germination energy,germination rate,and fresh weights,dry weights,seedling length,main root length,main root thickness,and side root number of seedling were observed and analyzed.The results showed that drought stress simulated with 5%PEG have significantly inhibited effects on the seed germination energy and germination rate,fresh weights,seedling length and side root number of seedling.These inhibition efficiency and effects were serious with the increasing of drought stress,but they were lowest on‘Zhongcao No.3’compared with‘Aohan’and‘Zhongmu No.1’.Meanwhile,the significant inhibited effect on main root thickness could be observed under drought stress simulated with 10%PEG in seedling of‘Zhongcao No.3’,but with 5%PEG in seedling of‘Aohan’and‘Zhongmu No.1’.Therefore,it could be deduced that the drought-tolerance of‘Zhongcao No.3’was better than‘Zhongmu No.1’or‘Aohan’,this finding could provide a certain theory evidence and reference value for the cultivation of alfalfa in Inner Mongolia.