草地早熟禾叶片和根颈对低温胁迫的生理响应

以甘肃省定西市安定区采集的野生草地早熟禾为材料,探讨低温胁迫对草地早熟禾不同营养器官的伤害以及不同器官的抗寒性差异,以期为草地早熟禾草坪养护管理提供依据。结果表明:随低温胁迫时间的延长,草地早熟禾叶片和根颈可溶性糖(SS)、游离脯氨酸(Pro)含量逐渐增加,其中,叶片Pro和SS含量在第6 d时显著高于对照,根颈内两者含量分别在第6 d和第10 d时显著高于对照;可溶性蛋白(SP)、丙二醛(MDA)、过氧化氢(H_2O_2)、羟自由基(·OH)含量和超氧自由基(O_2~-·)产生速率及过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)活性均呈先增加后降低的趋势,第8 d达最大值,且显著高于对照(P0.05);叶片对低温胁迫的伤害比根颈更加敏感。

Physiological response of leaf and root collar of kentucky bluegrass to cold stress

In order to provide theory basis for better turf management,the damage and tolerance of root col-lar and leaf of wild kentucky bluegrass materials collecting from Anding,Gansu under cold stress were studied. The results showed that the content of soluble sugar (SS) and free proline (Pro)in root collar and leaf in-creased gradually with the extension of cold stress time,and the contents of SS and Pro in leaf were significantly higher than those of control after 6-day cold stress (P<0.05),while the contents in collar were significantly higher than those of the control after 6-day and 10-day cold stress,respectively (P<0.05).The content of solu-ble protein (SP),MDA,hydrogen peroxide (H2O2 ),generation rate of superoxide(O2-·),hydroxyl free radical (·OH),activity of CAT,POD and SOD in root collar and leaf increased gradually and reached maximum values after 8-day cold stress and were significantly higher than those of the control (P<0.05).The results suggested that leaf was more sensitive to cold stress than the root collar.