花后不同强度遮光对糯小麦和非糯小麦干物质积累和产量的影响

为了解糯小麦和非糯小麦对遮光的生理反应差异,在大田条件下,以非糯小麦轮选987和糯小麦农大糯50206为材料,设置3个遮光处理(不遮光、花后遮光30％和60％),研究了花后不同强度遮光对糯小麦和非糯小麦干物质积累和产量的影响.结果表明,遮光后,轮选987和农大糯50206的生物产量、籽粒产量和经济系数均显著下降.花后光照强度降低导致小麦花前营养器官干物质在花后向籽粒的转运量及其贡献率发生明显变化,同时影响籽粒灌浆进程,最终表现为粒重显著下降,且此影响存在明显的基因型差异.轮选987在遮光30％后营养器官干物质在花后向籽粒的转运量降低,遮光60％后转运量恢复至对照(不遮光)水平,转运物质对籽粒的贡献率随遮光强度的提高而增加.花后遮光抑制了农大糯50206花前营养器官干物质在花后向籽粒的转运,但未改变转运物质对籽粒的贡献率.花后弱光降低了小麦籽粒的平均灌浆速率和最大灌浆速率,轮选987的灌浆进程不受影响,却改变了农大糯50206的灌浆进程,延长了其渐增期和快增期的天数,推迟了灌浆高峰期的来临.遮光后小麦败育小穗数增多,穗粒数下降.花后遮光致使小麦产量降低的程度存在基因型差异,农大糯50206产量的降幅明显小于轮选987.

Effects of Different Shading Intensity after Flowering on Dry Matter Accumulation and Yield of Waxy and Non-waxy Wheat

In field conditions, glutinous wheat cultivar Nongdanuo 50206 and non-glutinous wheat cultivar Lunxuan 987 were selected to study the effects of post-flowering shading on dry matter accumulation and yield of wheat. Three treatments were designed with shading off 0, 30%, and 60% sun light using black plastic net after wheat anthesis. The results indicated that the biological yield, grain yield and economic index of wheat were decreased significantly with low light intensity during grain-filling stage. The translocation of dry matter produced in vegetative organs before flowering to grain and its contribution to grain yield were greatly affected by shading. At the same time, low light changed wheat grain-filling process. As a result, grain weight decreased significantly. The effects of low light on dry matter translocation and grain-filling process varied with wheat genotypes. In non-glutinous cultivar Lunxuan 987, slightly shading decreased the translocation amount of dry matter from vegetative organs to grain, while the amount was up to the control level under seriously shading conditions. With the decrease of light intensity in Lunxuan 987 canopy after anthesis, the contribution rate of dry matter translocation to grain was increased. The translocation of dry matter in glutinous cultivar Nongda 50206 from vegetative organs to grain was suppressed by low light intensity, but the contribution rate to grain was not affected. Shading after anthesis declined the mean and maximum grain filling rates in both glutinous and non-glutinous wheat. The grain-filling process of glutinous cultivar Nongdanuo 50206 was changed by low light, which showed that slight-increase and fast-increase periods were prolonged, and the time of maximum filling rate was delayed, while the grain-filling process of non-glutinous cultivar Lunxuan 987 was influenced slightly. Shading after anthesis increased the number of sterile spikelet, which reduced the kernels per spike in both cultivars. As a result, wheat grain yield was markedly decreased under low light conditions during grain filling stage, and non-glutinous wheat cultivar Lunxuan 987 were more seriously affected than glutinous wheat cultivar Nongdanuo 50206.