干旱胁迫对不同紫花苜蓿品种生产性能的影响

Comparison of production performanceyield of 8 alfalfa cultivars under drought stress

为了解不同紫花苜蓿品种对干旱胁迫的响应,探讨了干旱胁迫对8个紫花苜蓿品种生产性能的影响。试验采用随机区组设计,包括3个土壤水分梯度,水分梯度分别为80%(对照)、55%和30%的田间最大持水量。结果表明,随着干旱胁迫的加剧,8个紫花苜蓿品种的地上生物量和地下生物量逐渐降低,BC-9紫花苜蓿和肇东苜蓿的地上生物量受干旱胁迫的影响较轻,均值分别为3.11和2.75 g/盆;地下生物量分别为1.34和0.65 g/盆;干旱胁迫严重影响了河南苜蓿和博维,地上生物量分别为1.87和1.85 g/盆,地下生物量分别为0.75和0.91 g/盆。随着含水量的减少,8个紫花苜蓿品种的分枝密度、株高以及干旱胁迫前后的变异系数逐渐减小。生物量、分枝密度和株高随着含水量的降低而降低,呈正线性关系(R2=0.96~0.99)。

In order to understand the response of alfalfa to drought stress,a greenhouse experiment was conducted to investigate the effects of drought stress on the performance of 8 alfalfa cultivars.A random completely block experiment was conducted between alfalfa cultivars and drought stress.There were 3 drought stress levels including 80%(control),55%and 30%of field water holding capacity.The result demonstrated that the aboveground and belowground biomass decreased gradually with increasing levels of drought stress.The aboveground biomass of BC-9 alfalfa and Zhaodong was less affected by drought stress than other alfalfa cultivars,with the means of the 2 cultivars being 3.22 and 2.75 g DM/pot,respectively,and the means on belowground biomass was 1.34 and 0.65 g/pot,respectively.Henan alfalfa and Bowei were affected severely by drought stress,With the mean aboveground biomass being 1.87 and 1.85 g/pot,and the mean belowground biomass 0.75 and 0.91 g DM/pot,respectively.Branch density and plant height gradually decreased with increasing water stress.There were positive relationships(R2=0.96~0.99)between water content and biomass,and between branch density and plant height.This indicated that plants may have altered their shoot and root structures in order to avoid damage in the progress of water deficit.Understanding the effect of water deflict on production performance of alfalfa under drought stress can help provide the mechanism basis in drought tolerance in the future.