北部冬麦区主栽品种光合产物贮运特性研究

为解析北部冬麦区小麦品种光合产物积累与转运遗传特性,以近20年内主要推广的7个小麦品种为材料,通过两年两点田间试验,研究不同品种的生长发育生理动态、不同营养器官干物质积累分配、收获指数及籽粒产量。结果表明,收获指数和生物量对产量有显著影响。中麦816和中麦175具有较高产量潜力,分别为4 923.0 kg·hm^-2和4 913.0 kg·hm^-2,主要与其较高的生物学产量和收获指数有关。苗期群体光截获面积、灌浆期光能利用效率对干物质积累有重要影响。研究发现,灌浆期叶绿素含量低、旗叶面积小、光合速率高的品种,干物质积累效率较高,叶片和茎秆中可溶性糖贮积较多,如中麦175。在营养器官干物质分配方面,开花期中麦816和中麦175的各营养器官干物质贮积与其他品种差异较小,但成熟期叶片、茎秆干物质转运效率较高,贮积物残余较少,开花前中麦175和中麦1062贮藏的光合同化物对籽粒贡献最高。通过育种选择可提高光能利用效率和产量潜力,开花前干物质积累量和灌浆期干物质转运效率的选择,可减少成熟期营养器官光合产物残余,从而提高干物质向籽粒的转化效率。本研究进一步明确了新品种选育的目标与方向。

Accumulation and Partitioning Characteristics of Photosynthetic Product of 7 Main Cultivars in Northern Winter Wheat Zone

The objectives of the present study were to analyze the dry matter accumulation and partitioning characteristics of wheat cultivars in the Northern Winter Wheat Zone (NWWZ). Seven elite cultivars from the NWWZ during the past 20 years were selected and planted at two experimental sites in two cropping seasons. The dynamic accumulation and transportation of dry matter in different organs during grain-filling, harvest index (HI), and grain yield of all cultivars were investigated. The results showed that the HI and biomass had significant effects on yield. Zhongmai 816 and Zhongmai 175 had higher yield potential, which were 4 923.0 kg·hm^-2 and 4 913.0 kg·hm^-2, respectively, mainly attributed to their higher biomass yield and HI. The analyses of dry matter accumulation revealed that photosynthetic area at seedling stage and the photosynthetic utilization efficiency during grain filling stage had important effects on dry matter accumulation. Cultivars with low chlorophyll content, small flag leaf area (FLA), and high photosynthetic rate (Pn) during the grain filling stage had higher dry matter accumulation efficiency and more soluble sugar storage in stems and leaves, such as Zhongmai 175. In term of the dry matter distribution in vegetative organs, the dry matter storage of vegetative organs in Zhongmai 816 and Zhongmai 175 at the flowering stage was slightly different from that of other cultivars, but the dry matter transportation efficiency in stems and leaves at the maturity stage was higher, and the residues of stored matter was less. In addition, the photosynthetic compounds stored in Zhongmai 175 and Zhongmai 1062 before flowering had the highest contributions to grains than other cultivars. That demonstrated that improving the light energy utilization efficiency of cultivars was a feasible way to increase the genetic yield potential. In addition, the selection of dry matter accumulation before the flowering stage and the dry matter transportation efficiency at grain filling stage is helpful to reduce the residual photosynthetic products in tissues and organs at maturity, and improve the efficiency of transporting substance to grains. This study can determine the future breeding improvment target and direction for new wheat cultivars in the NWWZ.