遮光对玉米干物质积累及产量性能的影响

Effects of Shading on Dry Matter Accumulation and Yield Capability of Maize

选用玉米品种郑单958与先玉335,在大田条件分别于7叶全展期(T1)、13叶全展期(T2)、吐丝期(T3)、吐丝后15 d(T4)进行50%遮光处理,研究不同时期遮光对玉米干物质积累与产量性能的影响。结果表明,不同时期遮光均导致玉米终极生长量(a)、干物质积累速率最大时的生长量(Wmax)、最大干物质积累速率(Gmax)、平均叶面积指数(MLAI)、平均净同化率(MNAR)和收获指数(HI)降低,致使干物质积累与产量不同程度降低,吐丝后15 d遮光对干物质与产量影响最大。在产量构成因素中,遮光处理对穗粒数与千粒重影响较大,穗粒数减少占主导,其次是千粒重的降低。

Field experiments were conducted using maize cuhivars（Zhengdan958, Xianyu335） with shading of 50% at different stages to explore the effect of low light stress on dry matter accumulation characteristics and yield ca- pability of maize. Shading treatments were conducted during the 7th leaf full）, open（treatment T1）, and the 13th leaf fully open（treatment T2）, and the silking（treatment T3）, and the 15th day after silking（treatment T4）and natural light condition without shading was used as the control. Each shading treatment would lasted 7 days. The results showed that, the maximum growth biomass（α）, weight reaching maximum dry matter accumulation rate（Wmax）, the maximum dry matter accumulation rate（Gnu）, mean leaf area index（MLAI）, mean net assimilation rate（MNAR） and harvest index（HI） decreased under shading conditions, the yield and dry matter accumulation then reduced in different degree corre- spondingly. Generally, the treatment T4 had the most important influence on yield and dry matter accumulation than other treatments. The results suggested that grain number per ear than 1 000-kernel weight were greatly influence by shading than other yield components.