缺水条件下冬小麦的光能吸收和干物质积累运转的分析

An Analysis of Solar Radiation Absorption and Dry-matter Accumulation and Transport in Winter Wheat under Water Stress Conditions

应用品种Brock和Renard在温室和大田试验结果表明生物量与光能吸收量呈线性关系;温室受旱作物生育后期光能转化效率降低.水分亏缺主要通过降低光能吸收量,其次通过降低光能转化效率影响生物量积累.总生物量及茎鞘生物量积累都明显受到中、后期缺水的抑制,以开花前缺水的影响为甚.两品种生物量积累方式不同,Renard开花后积累转慢.缺水强化了茎鞘贮存物质的重新分配,尤以灌浆期缺水为甚.籽粒灌浆过程可用三段折线模式来拟合.开花前缺水使灌浆增强,部分地补偿了粒数的降低;后期干旱影响灌浆致使粒重降低.两品种属于不同灌浆类型,似乎短快型对避开后期干旱较有利.

Lineor relations between biomass and radiation absorption were revealed in the well-irrigated treatments(control) in the glasshouse and all treatments in the field by trials using two cultivars, Brock and Renard. But the crop stressed by drought pre-anthesis ( F1 ) reduced the solar radiation conversion effe-ciency over the late growing period. The biomass accumulation was negatively affected mainly by the reduction of radiation absorbed, and to some less extent the conversion effeciency. Total and stem biomasses both were remarkably depressed by water stresses imposed preanthesisa and grain-filling periods, among which, more by the pre-anthesis drought. The patterns in biomass accumulation varied in two genotypes, for the accumulation in Renard post-anthesis turned slow. Water stresses intensified the removal of reserves from stems, more removal occurred in the late season stressed treatment. The course of grain filling could be well fitted by a three-phase segmented model. Pre-anthesis water stress quickened the grain growth to compensate partially the lowered grain number per ear; but late drought affected grain filling and thus the grain weight. Different patterns of grain filling were shown in the two cultivars, suggesting that the patterm of short-fast grain filling seem to enable the crop to escape the drought stress during late period.