灌浆期不同阶段高温胁迫对春小麦籽粒生长的影响

Effect of Heat Stress during Grain Filling on Grain Growth of Spring Wheat Varieties

灌浆期短暂高温胁迫严重影响小麦产量。为了明确灌浆期不同阶段短暂高温胁迫对春小麦籽粒生长的影响,以强筋春小麦品种龙麦26和龙麦30为试材,在人工气候室(25℃/15℃)精确控温和人工温室形成绝对高温胁迫的条件下,分析了灌浆期不同阶段5d短暂高温胁迫对粒重的影响。结果表明,在灌浆期不同阶段短暂高温胁迫处理中,两个小麦品种均表现为:前期高温胁迫对粒重影响最大,达极显著水平(P<0.01);随着高温胁迫处理时期的后移,粒重降低幅度逐渐减小;后期(花后25d)高温胁迫对粒重影响不显著。灌浆期缩短是导致粒重降低的主要原因。

Short period heat stress is a significant factor limiting wheat yield in many wheat-growing areas. In order to examine the effect of short period heat stress on grain growth throughout the whole grain-filling period, two strong gluten spring wheat varieties（Longmai 26 and Longmai 30） were grown in pots at diurnal temperatures（25/15 ℃ ） in climate-controlled growth cabinets and exposed to a 5-day heat stress at 5-day intervals throughout grain filling from anthesis to mature in the glasshouse. The results showed that kernel weight was most sensitive to heat stress during early stage of grain filling and became progressively less sensitive throughout grain filling, for both varieties. From the 25 days after anthesis, the short period of heat stress had no significant effect on kernel weight. Reductions in kernel weight resulted primarily from the shortening of grain filling stage.