覆雪对不同秋眠型紫花苜蓿生理特性及抗寒基因表达的影响

Effects of Snow Cover on Physiological Characteristics and Cold Resistance Related Gene Expression of Alfalfa Varieties with Different Fall Dormancy Levels

为明确田间覆雪对不同秋眠型紫花苜蓿生理特性及抗寒基因表达的影响,选择秋眠型紫花苜蓿肇东(1级)、半秋眠型紫花苜蓿Archer(5级)及非秋眠型紫花苜蓿WL903(9级),测定越冬期间苜蓿的越冬率、根部渗透调节物质(可溶性糖、脯氨酸)含量、抗氧化物酶(超氧化物歧化酶、过氧化物酶)活性以及抗寒相关基因(CAS 15A、DREB1、NAC3)表达。结果表明:冬季积雪可提高不同秋眠级紫花苜蓿的越冬率。覆雪状态下紫花苜蓿主根可溶性糖和脯氨酸含量、以及超氧化物歧化酶和过氧化物酶活性均高于不覆雪状态;紫花苜蓿DREB1基因的表达量在秋眠型苜蓿(肇东)中最高,CAS15A和NAC3基因的表达量在半秋眠型苜蓿(Archer)中最高。

Three alfalfa varieties(Zhaodong,Archer and WL903)with different fall dormancy levels(FD1,FD5 and FD9)were selected to study the effects of field snow cover on physiological characteristics and cold resistance related gene expression.The overwintering rate,osmotic regulator contents(soluble sugar,free proline),antioxidant enzyme activities(superoxide dismutase and peroxidase)and the expression of cold resistance related genes(CAS 15A,DREB1,NAC3)in alfalfa roots were determined under either snow-covered or non-snow-covered conditions.The results showed that snow cover can increase the overwintering rate of alfalfa varieties with different fall dormancy levels.The contents of soluble sugar and proline,and activities of superoxide dismutase and peroxidase of the alfalfa taproot under the snow-covered condition were higher than those under non-snow-covered condition.The expression of DREB 1 was the highest in fall dormant alfalfa(Zhaodong),and the expression of CAS15A and NAC3 was the highest in semi-dormant alfalfa(Archer).