外源甲醇对油菜种子萌发和幼苗生长的影响

Effect of Exogenous Methanol on Seed Germination and Seedling Growth of Brassica napus L.

以中国南、北2个主要栽培品种‘玉油二号’和‘秦油二号’油菜种子为供试材料,采用溶液培养方法研究了0～2 000 mmol·L-1甲醇溶液处理下,油菜种子萌发、幼苗生长特征及其相关生理生化指标的变化.结果表明：（1）10～1 000 mmol·L-1甲醇处理的油菜种子萌发指标（发芽率、发芽势、发芽指数、活力指数）和幼苗生长指标（幼芽及幼根长度、鲜重、根冠比）均比对照显著增加,而甲醇溶液浓度为2 000 mmol·L-1时油菜种子萌发和幼苗生长受到显著抑制;两个油菜品种种子萌发和幼苗生长在甲醇溶液处理下均表现为相同的变化趋势,但也存在品种的差异,‘秦油二号’生长受影响程度低于‘玉油二号’.（2）随着甲醇溶液浓度的增加,油菜种子萌发指标和幼苗生长指标表现出先增加后降低的趋势,并在甲醇溶液浓度为100 mmol·L-1时均达到最大值,继续高于此浓度后促进作用即减弱以至消失,甚至产生抑制作用.（3）随着甲醇处理溶液浓度的增加,油菜幼苗叶片的叶绿素含量呈先增后降的趋势,而同期叶片的MDA和过氧化氢含量却呈先降后升的相反趋势,且均在相同的100 mmol·L 1浓度下分别达到最大或者最低值.研究认为,适宜浓度的甲醇溶液能够促进油菜种子萌发和幼苗生长.

To determine the effect of different concentration methanol solution on seed germination and seedling growth of Brassica napus L.,we chose two main varieties ‘Yuyou 2’ and ‘Qinyou 2’ as materials to be cultured by water or 10 2 000 mmol · L-1 methanol solutions.Seed germination,seedling growth properties and its related physiochemical indices were analyzed.The results indicated that：（1）10-1 000 mmol· L-1 methanol solution obviously enhanced seed germination parameters （including germination rate,germination potential,germination index and vigor index） and seedling growth parameters（including shoots length,roots length,fresh weight and root/shoot ratio） of B.napus L.than that of the control,but the these parameters significantly reduced at 2 000 mmol · L-1.The two varieties showed the same trend under methanol solution treatment,but there were also slight differences in the two varieties,i.e.‘Qinyou 2’ was affected lower than ‘Yuyou 2’.（2）With increasing concentrations of methanol,B.napus L.seed germination index and seedling growth index increased at first,but decreased later.With 100 mmol· L-1methanol solution treatment,seed germination parameters and seedling growth parameters of B.napus L.reached the highest value.With higher concentration,the promotion was weaken or disappear,even damp en.（3）With increasing concentrations of methanol,B.napus L.seedling leaves chlorophyll content also showed an increasing trend and decreased at late.The MDA and hydrogen peroxide contents at first fell after the raised of the opposite trend in the same period.The results showed that the appropriate concentration of methanol solution could promote seed germination and seedling growth of B.napus L..