4个柏木种源的抗寒性与抗旱性评价

Evaluation of cold and drought resistance of four cypress provenances

以四川三台、湖北京山、重庆酉阳和浙江开化4个种源柏木的(Cupressus funebris)2年生实生苗为对象,分别进行了低温与干旱胁迫处理。通过观测表型以及测定针叶的相对和绝对含水量、相对电导率、光合色素含量、丙二醛含量、游离脯氨酸含量等指标,采用隶属函数分析法,对4个种源柏木的抗寒性与抗旱性进行了评价。结果表明:(1)低温胁迫下,随着温度的降低,所有种源植株的相对电导率明显上升;叶绿素含量显著降低,类胡卜素含量的变化趋势不明显;丙二醛和脯氨酸含量显著提高。4个种源对低温胁迫的响应和耐受程度有所不同,其抗寒性由强到弱排序为:浙江开化>四川三台>重庆酉阳>湖北京山。(2)干旱胁迫下,植株生长减缓,并出现明显失水症状。干旱30 d时,针叶的相对电导率和丙二醛含量明显上升,光合色素含量显著降低,复水10 d后均恢复至对照水平;脯氨酸含量亦显著增加,但复水后未达到对照处理水平。4个种源对干旱胁迫的响应和耐受程度亦明显不同,其抗旱性由强到弱排序为:重庆酉阳>四川三台>湖北京山>浙江开化。

Some 2-year-old Cupressus funebris seedlings from four different provenances(Sichuan Santai,Hubei Jingshan,Chongqing Youyang,and Zhejiang Kaihua)were adopted as the materials in the present study to evaluate their cold and drought tolerance by low-temperature and drought stress treatments,respectively.Under the stress treatment,the morphology,relative and absolute water content,relative membrane permeability,photosynthetic pigment content,malondialdehyde content,and proline content of the needles were investigated,respectively,and based on the membership function analysis,the cold and drought resistance of the four provenances were evaluated.The results showed that:(1)Under low-temperature treatment,the relative membrane permeability of all plants increased obviously with the decrease of temperature;the content of chlorophyll decreased significantly,while the carotenoid content changed indistinctively;the content of malondialdehyde and proline increased significantly.The response and tolerance of the four provenances to low-temperature stress were different remarkably,and their cold resistance ranked as:Zhejiang Kaihua>Sichuan Santai>Chongqing Youyang>Hubei Jingshan.(2)Drought stress decreased the plant growth and caused obvious water-loss symptoms.After drought treatment for 30 days,the relative membrane permeability and malondialdehyde content in the needles increased significantly,coupled with significantly decreased photosynthetic pigment content,and their values recovered to the control level after 10-day rehydration;the proline content increased significantly as well,but it did not reach the control level at the end of the experiment.were different obviously,and the order of drought resistance of the four provenances was:Chongqing Youyang>Sichuan Santai>Hubei Jingshan>Zhejiang Kaihua.