6种野生耐旱花卉幼苗叶片脱水和根系含水量与根系活力对干旱胁迫的反应

Responses of Dehydration of Leaves and Water Content and Activity of Root to Drought-Stress of Six Wild Flowers

研究了燕山东段6种野生耐旱花卉幼苗在持续干旱胁迫至枯死临界点过程中盆栽土壤含水量、叶片脱水、根系含水量与根系活力的变化。结果表明,6种野生耐旱花卉幼苗的耐旱性强弱顺序依次是叶底珠>栓翅卫矛>木半夏>孩儿拳头>南蛇藤>蚂蚱腿子,而叶片萎蔫脱落与枯萎表征出现的时间和耐旱性之间没有必然的联系,栓翅卫矛和木半夏以叶片延迟脱水耐旱,其叶片在土壤干旱过程中萎蔫和枯萎表征出现最晚;叶底珠和孩儿拳头以叶片较快脱水耐旱,其叶片在土壤干旱过程中含水量迅速下降,叶片萎蔫脱落表征出现较早;南蛇藤和蚂蚱腿子叶片萎蔫脱落表征出现时间介于上述两种类型之间,在6种材料中相对不耐旱。根系含水量随着干旱胁迫的加剧呈逐渐下降趋势,自由水与束缚水比值和根系活力的变化趋势相似,都有一个增大的过程,增大的峰值出现的时间各不相同,随后开始下降,至枯死临界点降到最小值;峰值的出现是对干旱胁迫的一种适应。

Changes of soil＇s water content, dehydration of leaves, root＇s water conten and activity of roots of the six wild flowers were studied in the easten section of Yanshan Mountain. The results showed that the tolerance of the species was in order of Securinega suffruticosa （Pall.） Rehd. 〉 Euonymu phellomanus Loes. 〉 Elaeagnuas multi flora Thunb. 〉 Grewia biloba var. parvi flora （Bge.） Hand. 〉 Celastrus orbiedatus Thunb. 〉 Myripnois dioica Bge. There was not necessary relationship between leaf abscission, the time when the wilting leaf appeared and the ability of drought-torance. Euonymu phellornanus Loes. and Elaeagnuas multi flora Thunb. were belonged to delay dehydration species that the time that the wilting leaf appeared ,vere the latest; Securinega suffruticosa （Pall.） Rehd. and Grewia biloba var. parviflora （Bge.） Hand. were belonged to the species that endure drought stress by leaf abscission. The leaves＇ water content dramatically decreased and the time that the wilting leaf of them appeared were the earliest; The time that the wilting leaf of Celasirus orbiculatus Thunb. and Myripnois dioica Bge. appeared were between them and had the least ability of drought-torance. The root＇s water content gradually decreased with the drought stress. The trends of the ratio to free water of bound water and root activity were similar, they increased at first and then decreased and reach the minimizeat the dead point. The time appeared of increasing peak was different for the six plants and the peak was adapt to the drought stress.