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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。
The changes of soil water content, leaf dewatering, root water content and root activity of six wild drought-tolerant flower seedlings in the eastern Yanshan section from the duration of drought stress to the critical point of death were studied. The results showed that the order of drought tolerance of the six wild drought-tolerant flower seedlings was as follows: leaf basal spike> Plutella xylostella> Banxiaxia> child fist> southern snake vine> grasshopper leg, while leaf wilting shedding and wilt characterization There is no necessary relationship between the emergence time and the drought resistance. The results showed that the leaves were delayed and dewatered and drought-tolerant in leaves, and the wilting and wilting appearance of the leaves appeared in the soil at the latest. The leaves dehydrated quickly and droughts. The leaf water content of the leaves decreased rapidly in the process of soil drought, and the wilting and detachment characteristics of the leaves appeared earlier. The wilting and detachment characteristics of the leaves of P. coccinea and grasshopper leg appeared between the above two types. 6 kinds of materials are relatively drought-resistant. The root water content decreased gradually with the increase of drought stress. The trend of free water and irreducible water ratio and root activity were similar, and there was an increasing process. The increasing peak appeared different time and then began to decline , Until the critical point of death to the minimum; peak appears to be an adaptation to drought stress.