干旱-低温交叉逆境下小麦渗透调节能力的变化与交叉适应的关系

Relationship between changes of osmotic adjustment ability of wheat under drought and cold cross-stress and cross-adaptation

利用砂培的方法研究了3个抗旱、抗寒性不同小麦品种在干旱、低温交叉逆境下渗透调节物质及渗透调节能力的变化与交叉适应的关系。结果表明,3个小麦品种经适度的干旱、低温单一逆境处理后,可溶性糖、脯氨酸、游离氨基酸和可溶性蛋白质的含量均升高,表现出了一定的渗透调节能力;经交叉逆境(干旱+低温,低温+干旱)处理后,上述几种渗透调节物质含量进一步升高,渗透调节能力明显增强(晋麦47渗透调节能力分别升高了66.38%和51.27%;郑引1号分别升高了71.77%和71.09%;长武6878分别升高了56.36%和62.91%),质膜相对透性明显降低(与单一逆境相比,晋麦47膜透性分别下降了23.03%和22.94%;郑引1号分别下降了20.27%和8.91%;长武6878分别下降了28.17%和23.44%)。同时从实验数据可见在逆境条件下,抗性品种的渗透调节能力显著高于敏感品种。上述结果表明植物对不同逆境的适应存在着某些共同的生理基础,其中在交叉逆境下植物渗透调节能力的增强是交叉适应的可能生理机制之一。

The relationship between changes of osmotica content and osmotic adjustment ability of wheat seedlings under drought and cold cross-stress and cross-adaptation was studied with sand culture in artificial illumination incubator.The result showed that the content of soluble sugar,proline,amino acid and soluble protein increased in the seedlings of the 3 wheat varieties under one stress（drought or cold）,and the wheat varieties showed certain ability of osmotic adjustment.Under drought and cold cross-stress（drought ＋ cold or cold ＋ drought）,the osmotica content and osmotic adjustment ability increased obviously（the ability of osmotic adjustment increased by 66.38% and 51.27% in Jinmai47,by 71.77% and 71.09% in Zhengyin No.1,and by 56.36% and 62.91% in Changwu 6878）.The relative permeability of plasma membrane reduced as compared with one stress,drought or cold（the relative permeability of plasma membrane reduced by 23.03% and 22.94% in Jinmai47,by 20.27% and 8.91% in Zhengyin No.1,and 28.17% and 23.44% in Changwu6878）.The result also showed that the ability of osmotic adjustment of resistant varieties was notably higher than susceptive varieties.When wheat was treated with cross adaptation for drought and cold,the pretreatment of one stress could increase resistance to another stress.It also showed that there was some common physiological metabolism under different stress,and enhancement of osmotic adjustment ability was one of the possible physiological metabolisms of cross adaptation under drought and cold cross-stress（drought ＋ cold or cold ＋ drought）.