糯小麦和非糯小麦干物质积累及产量对灌浆期不同阶段弱光的响应

为了解花后弱光照对糯小麦和非糯小麦产量形成的影响差异,在大田条件下,选用非糯小麦品种轮选987和糯小麦品种农大糯50222两个小麦品种为材料,分别于灌浆前期(花后1～10 d)、中期(花后11～20 d)和后期(花后21～30 d)进行遮去60％的光合有效辐射处理,研究花后弱光胁迫时期对小麦干物质积累和产量的影响.结果表明,与不遮光处理(对照)相比,灌浆中期和后期遮光造成轮选987的生物产量和籽粒产量显著降低,而农大糯50222在籽粒灌浆的前期和中期遮光后均显著降低.花后不同阶段遮光处理均造成小麦花前营养器官贮存干物质在花后向籽粒的转运量及其贡献率发生变化,此影响存在明显的基因型差异.轮选987表现为籽粒灌浆前中期遮光后转运量均显著降低,后期遮光后增加,转运物质对籽粒的贡献率则表现为前期遮光降低,中后期遮光提高,尤其是后期遮光提高幅度更大.农大糯50222花前干物质的转运量在遮光后均增加,以中期遮光后增加最多,转运物质对籽粒的贡献率在前中期遮光下均增大,以中期遮光最明显,后期遮光下贡献率下降.花后不同阶段遮光改变了小麦的灌浆进程.随遮光时间的推迟,轮选987籽粒灌浆的渐增期和快增期缩短.籽粒灌浆中期遮光延长了农大糯50222灌浆的快增期.灌浆中期遮光致使小麦产量和经济系数下降的幅度最大.

Effect of Low Light at Different Grain Filling Stages on Dry Matter Accumulation and Yield of Waxy and Non waxy Wheat

In field conditions, waxy wheat variety Nongdanuo 50222 and non waxy wheat cultivar Lunxuan 987 were used to study the effects of low light intensity at different grain filling stages on dry matter accumulation and yield. The photosynthetic active radiation was cut 60% by shading with black plastic net, and the natural condition was taken as the control. The results showed that biological yield and grain yield of Luxuan 987 decreased significantly after shading during middle and later grain filling stages, while those of Nongdanuo 50222 showed the similar trends after shading during early and middle grain filling stages. The translocation of dry matter, which produced in vegetative organs before flower, from vegetative organ to grain and its contribution rate were greatly affected by shading after anthesis, and the effect varied with wheat genotypes. The dry matter translocation of Luxuan 987 from vegetative organ to grain was decreased significantly after shading during early grain filling stage, but increased markedly after shading at later grain filling stage, which were the same as the contribution rate of dry matter translocation to grain. As to Nongdanuo 50222, shading after anthesis improved the translocation of dry matter from vegetative organ to grain, the highest translocation amount was observed for shading during middle grain filling period. With the delay of shading time, the contribution rate of translocation dry matter to grain increased and then decreased in Nongdanuo 50222, and the contribution rate of later shading treatment was below the control, other treatments were higher than the control. The grain filling processes of wheat were changed by low light intensity. With delay of shading time, the fast increase period and slow increase period of Luxuan 987 were shortened. The grain filling process of Nongdanuo 50222 was significantly affected by shading during middle grain filling stage, which extended the fast increase period. The grain yield and economic index of waxy and non waxy wheat were declined significantly by shading during middle grain filling stage.