山白兰的抗旱性评价

摘要

为了考察山白兰(Paramichelia baillonii)苗木的抗旱性,设置不同浓度聚乙二醇(PEG6000)处理,模拟干旱胁迫试验,测定苗木生长及生理生化指标,采用隶属函数值法综合评价山白兰的抗旱性.结果表明:山白兰的生长增量随着PEG6000胁迫浓度的增大而减少,胁迫浓度越大对苗木生长量的抑制作用越大;随着胁迫浓度的增加,山白兰叶片的超氧化物歧化酶(SOD)、过氧化物酶(POD)活性均呈先上升后下降的变化趋势,均高于对照(CK).在浓度10%处SOD、POD活性达到最大值.山白兰的细胞膜透性均随着PEG6000胁迫浓度的增加而增加,当PEG6000浓度为5%时,与对照差异不显著,当浓度高于5%时,膜透性急剧增加,高浓度胁迫对山白兰膜透性的伤害程度较高;山白兰的丙二醛(MDA)含量变化趋势与细胞膜透性的变化趋势一致,山白兰的MDA含量与PEG6000胁迫浓度呈极显著的负相关;当胁迫浓度低于10%时,脯氨酸含量增幅较小,高于10%时,增幅变大.脯氨酸含量与细胞膜透性、MDA含量呈显著或极显著正相关.通过模糊隶属函数法综合评价,山白兰的隶属综合值为0.472,属于中抗旱型.%In order to investigate the drought resistance of Paramichelia baillonii, different concentrations of polyethylene glycol (PEG6000) were set up to simulate the drought stress test,and the growth and physiolog-ical and biochemical indexes of the seedlings were measured to evaluate drought resistance of P. baillonii by us-ing membership function value method. Results showed that the growth increment of P. baillonii decreased with the increase of PEG6000 stress concentration,and the greater the stress concentration was,the greater the in-hibition was. With the increase of stress concentration,the activities of SOD and POD of the leaves of P. baillo-nii increased firstly and then decreased,and both were higher than those of CK. The activity of SOD and POD reached the maximum at 10%concentration. The cell membrane permeability of P. baillonii increased with the increase of PEG6000 concentration. When the concentration of PEG6000 was 5%,the difference was not sig-nificant. When the concentration was higher than 5%,the membrane permeability increased sharply. The dam-age degree of high concentration stress on the membrane permeability was higher. The change trend of MDA content was consistent with the change trend of cell membrane permeability,and the MDA content of P. baillo-nii was negatively correlated with the concentration of PEG6000. When the stress concentration was less than 10%,the increase of proline content was smaller. When the stress concentration was higher than 10%,the proline content increased largely,and there was a significant or extremely significant correlation between pro-line content,cell membrane permeability and MDA. Through the comprehensive evaluation of the fuzzy mem-bership function method, the subordinate comprehensive value of P. baillonii was 0.472, which belonged to the middle drought type.