抽穗期干旱胁迫对小麦产量及生理特性的影响

Effects of drought stress at heading stage on grain yield and physiological characteristics of wheat

为给小麦抗旱栽培提供理论参考,采用盆栽试验,在小麦抽穗期开始进行连续12d的干旱胁迫处理,设置中度干旱(MD,土壤相对含水量为40%~45%)、轻度干旱(LD,土壤相对含水量为55%~60%)及适宜含水量对照(WW,土壤相对含水量为75%~80%)3个水平,研究抽穗期干旱胁迫对小麦生理特性和产量形成的影响。结果表明,抽穗期干旱胁迫初期,剑叶抗氧化酶(超氧化物歧化酶、过氧化物酶、过氧化氢酶)活性均显著增加,轻度干旱处理酶活性均上升了30%左右,中度干旱处理3种酶活性均上升了75%左右。随着胁迫的延长,酶活性开始降低,胁迫程度越重,酶活性降低越快。膜脂过氧化产物丙二醛(MDA)大量积累,积累量随胁迫程度的加重而增加。干旱胁迫显著影响小麦产量的形成,轻度干旱胁迫影响了粒重形成,产量下降了21.57%,中度干旱胁迫影响了每穗粒数和粒重的形成,产量下降了40.56%。

In order to provide theoretical support for drought resistant cultivation of wheat a pot experimeon the soil relative water content （SRWC） at heading stage lasting for 12 days to study the effects of drought stress on physiologi-cal characteristic and grain yield formation of wheat. The treatments were designed with target SRWC of 40%-45% for treatment MD （moderate drought） ; 55%-60% for treatment LD （light drought） and 75%-80% for treatment WW （wel-watered）. Treat-ment WW was used as the control. The results show that the anti-oxidant enzymes （SOD, POD and CAT） activities of flag leaf increase significantly at the initial stage of drought stress. The anti-oxidant enzymes activities of treatm30%, while the treatment MD increase by more than 75%. The enzymes activities begin to decline along with the prolonged stress time. The more serious the stress is, the faster enzymes activities decrease. The MtDA content of flag leaf increases with the increase of stress levels rapidly during the treatment Drought stress significantly affects the formation ofgrain yield. Light drought tres affects grain weight of wheat, while moderate drought stress affects both the formation of grains perpike and grain weight The grain yield of treatment LD and treatment MED decreases by 21. 57%