干旱胁迫对豌豆根系形态及产量的影响

采用盆栽方法,研究了55%的土壤相对含水量在分枝期、孕蕾期、花荚期进行15 d历时的干旱胁迫对豌豆干物质累积、根系生长及产量的影响。结果表明,与全生育期正常供水(75%)相比,三种干旱胁迫处理均降低了豌豆的干物质累积量,胁迫时期越早,复水对豌豆地上部干物质累积的补偿效果越好,分枝期干旱胁迫在成熟期达到了等量补偿;干旱胁迫均显著抑制了根系的生长,分枝期干旱胁迫对根系生长的抑制具有滞后效应,胁迫结束时与对照间差异不显著,在花荚盛期显著低于对照,孕蕾期干旱胁迫根系的复水补偿生长作用较好,各根系形态指标在成熟期均达到了超越补偿;三种胁迫方式均抑制了根瘤的形成及其生长,且复水后均产生了不足补偿,胁迫时期越早,补偿效果越差;花荚初期干旱胁迫对豌豆产量的抑制作用最大,比对照低20.41%,其次为孕蕾期,比对照低6.63%,分枝期干旱胁迫不影响子粒产量。

Effect of drought stress on root morphology and yield of pea

Pot experiments were conducted to study the effect of drought stress (55％ relative water content for 15 days) on dry matter accumulation,root system growth and yield of pea,with three treatments for timing at branching stage,budding stage and early flowering stage.The results showed that dry matter accumulation under three drought treatments was significantly reduced compared with that under the normal water supply (75 ％) during the whole growth stages.Besides,root growth was also significantly inhibited by drought stress,and the inhibition caused by stress at branching stage had hysteresis effect.Positive effect of re-watering on root growth was detected for drought stress at budding stage.Furthermore,all the three drought treatments inhibited the formation and growth of root nodules,and the compensation was inadequate after re-watering.In addition,the inhibition effect of stress at early flowering period on pea yield was the largest,with a reduction of 20.41％ in comparison with that of CK,followed by budding stage (6.63％ reduction),while that at branching stage was not significant.