新疆冬小麦不同产量群体冠层光截获与干物质分布特性分析

研究不同产量水平冬小麦群体冠层不同层次光合有效辐射(Photosynthetically Active Radiation,PAR)截获、干物质分布及产量的影响,为缩小新疆冬小麦产量差距、提高光能资源利用和高产栽培提供理论依据。试验于2018—2019年在军户和奇台两个不同试验区进行,以当地主栽品种为试验材料,采用综合管理模式模拟了超高产(SH:≥9000 kg·hm^-2)、高产(HH:7500~9000 kg·hm^-2)、农户(FP:6000~7500 kg·hm^-2)、基础(CK:≤4500 kg·hm^-2)4个产量水平。研究4个产量水平下新疆冬小麦开花期上、中、下冠层的光截获特性及干物质积累与分配特性,分析其与产量构成的相关性,探究增产途径。结果表明:产量水平高的群体在灌浆期仍能保持较高的叶面积指数(Leaf Ar?ea Index,LAI);随着产量水平的提高,冠层上、中、下层的PAR截获率和PAR截获量均提高,且总体表现为上层>中层>下层,呈现“上强下弱”的垂直分布特征,PAR透射率变化趋势与之相反;中层干物质积累量要低于上、下层干物质积累量,且上层干物质随着产量水平的升高增幅要大于中层和下层,干物质上、中、下层均与PAR截获率呈极显著相关,与籽粒产量的相关系数分别为0.97、0.90、0.78。可见花后维持较高LAI,提高光合有效辐射截获量(IPAR),增加开花后干物质积累,是实现小麦增产,缩小产量差的途径。

Analysis of canopy light interception and dry matter distribution characteristics of different winter wheat yield groups in Xinjiang

The effects of photosynthetically active radiation(PAR)interception,dry matter distribution,and the yield of winter wheat at different yield levels were studied to provide a theoretical basis for narrowing the yield gap,improving the utilization of light energy resources,and high-yield cultivation of winter wheat in the Xinjiang province.This experiment was conducted in Junhu and Qitai regions from 2018 to 2019.The main varieties planted in the region were used as experimental materials,and the integrated management model was adopted to simulate the four yield levels,namely,super high(SH:≥9000 kg·hm^-2),high(HH:7500-9000 kg·hm^-2),peasant household(FP:6000-7500 kg·hm^-2),and basic yields(CK:≤4500 kg·hm^-2).The characteristics of light interception,dry matter accumulation,and distribution in the upper,middle,and lower canopies of winter wheat at the four yield levels were studied,and the correlation between them and yield composition was analyzed to explore ways of increasing yield.The results showed that the population with a high-yield level could still maintain a high leafarea index(LAI)during its grouting stage.With production level increased,PAR interception rate and volume in the upper,middle,and lower layers of the canopy all increased,and the overall performance was greater in the upper than in the middle layer,presenting a vertical distribution characteristic of“strong at the top and weak at the bottom.”The variation trend of PAR transmittance was opposite.Dry matter accumulation in the middle layer was lower than in the upper and lower layers,and dry matter increase in the upper layer was greater than in the middle and lower layers,with an increase in yield level.The dry matter accumulation in the upper,middle,and lower layers was significantly correlated with the PAR interception rate,and the correlation coefficient with grain yield was 0.97,0.90,and 0.78,respectively.Therefore,maintaining high LAI,increasing PAR interception,and increasing dry matter accumulation after flowering are approaches to achieving increased wheat yield and reduced yield difference.