灌浆期高温和干旱对小麦灌浆特性的影响

在盆栽和人工气候箱模拟条件下,研究了高温与干旱胁迫对两个不同筋力小麦品种豫麦34号(强筋)和豫麦50号(弱筋)灌浆特性的影响.结果表明,高温胁迫抑制了子粒灌浆速率,使最大灌浆速率出现时间提前,灌浆持续期缩短,导致子粒干物质积累量下降.不同时段高温胁迫对粒重的影响有差异,豫麦34号和豫麦50号分别以前期和中期受高温胁迫影响最大,后期相对小.豫麦34号以中期干旱胁迫粒重降幅最大,而豫麦50号在前期受干旱胁迫影响最大,后期干旱使两品种的粒重略有增加.高温和干旱对小麦子粒灌浆特性及粒重的影响存在明显的水、温互作效应.研究还表明,渐增期平均灌浆速率的降低及快增期、缓增期持续时间的缩短是最终导致粒重降低的主要原因.

Effects of High Temperature and Drought Stress on Grain Filling Characteristics in Wheat during Grain Filling Period

Under pot conditions in the artificial weather room,two wheat cultivars with different gluten-strengths(Yumai 34,a strong-gluten cultivar,and Yumai 50,a weak-gluten cultivar) were used to investigate the effects of post-anthesis high temperature and drought stress on grain filling characteristics.The results indicated that high temperature stress decreased both grain filling rate and period,and caused early appearance of the maximal grain filling rate,thus reduced grain dry matter accumulation.However,the response of the two cultivars to high temperature at different grain filling stages were different: when suffered from high temperature in early and middle grain filling stage,the reduction in grain weight of Yumai 34 and Yumai 50 was relatively the greatest,respectively.While in the late grain filling stage,grain weight was less influenced by high temperature and drought in both wheat cultivars.The dry matter accumulation of the two cultivars was reduced by drought in early and middle grain filling stages.The reduction in grain weight in middle and early grain filling stage of Yumai 34 and Yumai 50 was relatively the greatest under drought stress,respectively.But grain weight was slightly increased in late grain filling stage under drought stress.The results also showed that significant interactions of high temperature and drought on grain filling characteristics existed in both wheat cultivars.The decrease of grain weight was mainly due to the suppression of grain filling rate during slow-increase stage,and duration of rapid-increase and slight-increase stage.