花后持续弱光对冬小麦光合特性及产量的影响

Effect of Weak Light after Anthesis on Photosynthetic Characteristics and Yield of Winter Wheat

为给弱光条件下小麦持续高产及耐荫性筛选提供一定的理论依据,在大田条件下,以济麦22和济核916为试验材料,于花后设置3个不同的遮光处理(不遮光、遮光30%和遮光60%),分析花后持续弱光对小麦光合特性和产量的影响。结果表明,济麦22和济核916旗叶叶绿素a、b含量在花后0~25d保持较高水平,之后迅速降低。遮光后两品种旗叶的净光合速率下降,济麦22的干物质积累量和花前贮存干物质在花后向籽粒的转运量及两品种的经济系数显著降低。花后遮光改变了小麦籽粒灌浆进程,显著降低了两品种的平均灌浆速率和最大灌浆速率,延长了济麦22的渐增期和快增期持续时间,减少了缓增期的持续天数,遮光60%处理显著降低了济核916渐增期持续时间,推迟了其灌浆高峰的来临时间。遮光30%和60%条件下济麦22分别减产27.7%和35.4%,济核916分别减产29.49%和64.39%。遮光后冬小麦的穗粒数和千粒重随遮光强度的增加而降低。说明花后弱光会降低小麦光合能力,不利于植株干物质积累和籽粒灌浆,最终导致减产。

In order to provide a theoretic wheat under weak light conditions, with treatments （no shading,30% of shading lyze the effects of continuous weak lig showed that the content of chlorophyll a al basis for the continuous high yield and shade tolerance of Jimai 22 and Jihe 916 as experimental materials, three shading and 60% shading of sun light after anthesis） were set to ana- ht on photosynthetic characteristics and yield. The results and b of the two varieties were not significantly decreased un- til 25 days after anthesis; the net photosynthetic lation and translocation of dry matter of Jimai 22 rate of the two varieties was decreased; the accumu were reduced and the economic coefficient of the two varieties was reduced significantly. Shading significantly changed the grain filling process, and reduced the mean filling rate and the maximum filling rate of the two wheat varieties. Shading also prolonged the slow-increase period and fast-increase period and reduced the duration of the slight-increase period of Jimai 22. The 60% shading treatment significantly decreased the slow-increase period of Jihe 916 and postponed the peak of filling stage. The yield of the two wheat cultivars was both decreased si nifieantly. The yield of Jimai 22 was reduced by 27.7% and 35.4% ,and the yield of Jihe 916 was r duced by 29.49% and 64.39% ,respectively, under shading treatment of 30% and 60%. After sha ing,the kernel number per ear and 1 000-grain weight of the two varieties were decreased with the d crease of light intensity.