干旱胁迫对大麦幼苗根系的影响

为了解干旱胁迫对大麦幼苗根系生长的影响，采用盆栽称重控制土壤含水量的方法，测定了土壤含水量为田间持水量的85%、55%、45%和35%等4个处理下， 4个抗旱性不同的大麦品种的幼苗根系形态和根系吸收能力等相关指标。结果表明，随着土壤含水量的减少，大麦幼苗的最长种子根、根尖数、根组织含水量均呈下降趋势；根分支数和根冠比总体呈上升趋势；根鞘大小和根毛密度整体上呈先上升后下降的趋势；根系活力与根总吸收面积和根活性吸收面积之间存在一定的互补效应。抗旱性较强的大麦品种较抗旱性较弱的品种，在干旱胁迫下能够保持更庞大的根系、更大的根-土交互面和更高的根系吸收能力。幼苗根系形态可以作为大麦耐旱性的筛选指标。

Effect of Drought Stress on the Roots of Barley Seedling

In order to know the effect of drought on the root of barley seedling,barley seedlings were grown in pots,in which the soil water content was maintained at 85%,55%,45% and 35% of field capacity(FC),respectively. Some conventional morphological and absorption capacity indexes in four different drought resistant barley cultivars were investigated. The results showed that the longest seminal root,the number of tips,tissue water content of the same cultivars are decreased with the decreasing of soil water centent,the number of forks,root/shoot ratio showed a rising trend in general,and the rhizosheath,root hair density raised at first and then decreased; there is a certain complementary effect among root activity,total absorption area and total active absorption area.The drought resistance barley cultivars have a larger root,root and soil interaction and a higher absorption capacity than the drought sensitive cultivars. Thus,the root morphological traits can be used as the screening indicator of barley drought resistance.