低温胁迫对萝卜幼苗抗寒性相关生理指标的影响

Effects of Cold Stress on the Physiological Indices of Radish in the Seedling Related with the Resistance to Cold

[目的]探索萝卜的耐寒机理,选育萝卜耐寒品种。[方法]以青大长和潍县萝卜2个品种为材料,研究低温胁迫对质膜透性(PMP)、叶绿素(chl)含量、过氧化物酶(POD)活性和脯氨酸(Pro)含量等与抗寒性相关的生理指标的影响。[结果]低温胁迫后9 d,青大长的相对电导率比对照高出18.68%,潍县萝卜比对照增加31.73%。低温胁迫后6 d,青大长幼苗叶片中chl、chla、chlb的含量分别比对照低了13.65%、10.83%、19.32%,而潍县萝卜分别比对照低了18.48%、16.49%、22.53%;青大长幼苗POD活性比对照上升了30.90%,而潍县萝卜比对照上升了11.11%。Pro含量青大长和潍县萝卜都于低温胁迫后9 d达到最大值,分别比对照高79.5%和70.1%。[结论]青大长的抗寒性大于潍县萝卜。

[ Objective ] The mechanism of the radish with the tolerance to cold was researched for its variety breeding. [ Method] The effects of cold stress on the physiological index such as the permeability of plasma membrane（ PMP）, the content of chlorophyll（ chl ） and proline and the activity of POD of two radish cuhivars（ Qingdachang and Weixian） was studied. [ Result] The conductivity of Qingdachang and Weixian was 18.68% and 31.73% higher than that of the CK after 9 days＇ treatment. And after 6 days＇ treatment the content of chl, chla and chlb in Qingdachang seedling was 13.65%, 10.83% and 19.32% lower than that of the CK; in Weixian seedling, 18.48%, 16.49% and 22.53% lower than that of the CK; the activity of POD in Qingdachang and Weixian seedling was 30.90% and 11.11% higher than that of the CK; and the content of Pro in both Qingdachang and Weixian reached the peak value（79.5% and 70.1% ） after the 9 days＇ treatment. [ Conclusion] The resistance of the Qingdachang to cold was lower than that of Weixian.