水分胁迫下闽楠和浙江楠幼苗的抗性研究

Study on Resistance of Phoebe bournei and Phoebe chekiangensis Seedlings under Water Stress

观察闽楠[Phoebe bournei(Hemsl.)Yang]和浙江楠(Phoebe chekiangensis C.B.Shang)移栽直至水分胁迫全过程,待幼苗长出的新叶至成熟进行水分胁迫试验,分别于胁迫后的7、14d和21d进行生理指标的测定。结果表明,在初期不同处理下闽楠和浙江楠的高度增长变化不显著。在3个不同的水淹处理情况下,苗木高度增长较快,且闽楠增长速度较浙江楠快。在外部形态方面,重度水淹情况下,闽楠、浙江楠叶片均出现红色,且浙江楠出现较早;后期排水试验中,叶片恢复,叶片红色变浅,植株仍可恢复生长。在生理特性方面,浙江楠幼苗MDA含量随胁迫程度的加强而增加,闽楠在轻度、中度淹水21d后,MDA含量呈下降趋势;浙江楠幼苗SOD活性随胁迫时间的延长呈先升后降趋势,闽楠在轻度、中度淹水胁迫下SOD活性始终呈上升趋势。表明闽楠幼苗能适应轻度、中度淹水环境,且抗旱性高于浙江楠幼苗,因而适宜在我国干旱和多雨地区园林绿化中推广种植。

The whole process of Phoebe bournei and Phoebe chekiangensis from transplanting until the water stress was observed,the physiological indicators after the stress 7,14 dand 21 dwere measured.The results showed that the height growth of P.bournei and P.chekiangensis was not significant at initial treatments.Under the three different flooding treatments,the height of seedlings increased rapidly,and the growth rate of P.bournei was faster than Phoebe chekiangensis.In the terms of external morphology,the leaves of P.bournei and P.chekiangensis all appeared red under heavy flooding,and P.chekiangensis appeared earlier.In the later drainage test,the leaves recovered and the plants could normally grow again.In the terms of physiological characteristics,its MDA contents increased with the strengthening of drought degree in P.chekiangensis.In P.bournei,its MDA content decreased under mild and moderate flooding after 21 d,its SOD activity increased first and then decreased with the stress time prolonging in P.chekiangensis,but for the P.bournei,it was rising steadily in mild and moderated flooding.The results proved that seedlings of P.bournei could adapt to mild and moderate flooding environment,and drought resistance was higher than that of P.chekiangensis seedlings.P.bournei was more suitable for planting in arid and rainy areas than P.chekiangensis.