种植密度和播期对周麦18碳氮转运、籽粒淀粉及蛋白质含量的影响

在大田条件下,研究了不同种植密度和播期对冬小麦品种周麦18干物质和氮素积累转运及其籽粒产量和品质的影响.结果表明,不同播期各密度处理开花期和成熟期单茎干物质和氮素积累量均随播种密度降低而增加(150×104株/hm2>225×104株/hm2>300×104株/hm2),晚播相应降低了单茎干物质和氮素积累量及穗部积累量.正常播期低密度(150×104株/hm2)和晚播中等密度(225×104株/hm2)提高了成熟期营养器官总的干物质和氮素积累量,增加了营养器官花前贮藏干物质总转运量及其对籽粒重的贡献率.正常播期中低密度(150×104株/hm2和225×104株/hm2)和晚播中高密度(225×104株/hm2和300×104株/hm2)处理相应提高了籽粒淀粉、蛋白质含量与产量及籽粒产量,保证了小麦籽粒产量和品质同步提高.因此,晚播小麦通过适当增加播种密度,可以改善植株的碳氮代谢状况,提高籽粒产量.本试验条件下,偏多穗型晚播小麦兼顾高产和优质的正常播期和晚播小麦适宜播种密度分别为:150～225×104株/hm2、225～300×104株/hm2.

Effects of Plant Density and Sowing Date on Translocation of Carbon and Nitrogen, and Grain Starch and Protein Contents for Wheat Cultivar Zhoumai 18

The objective of this study is to investigate the effects of plant density and sowing date on the accumulation and translocation of dry matter and nitrogen for winter wheat cultivar Zhoumai 18.Results; With decreasing sowing density, the accumulation amounts of dry matter and nitrogen per stem at anthesis and maturity are increased ( 150 × 10Vhm~2 >225 × 10~4/hm~2 > 300 × 10~4/hm~2) for winter wheat cultivar " Zhoumai 18". Late sowing impairs the improvement of dry matter and nitrogen accumulation. Normal sowing date with low sowing density (150 × 10 / hm~2) and late sowing date with middle sowing density (225 × 10~4/hm ) significantly enhance the total accumulation of dry matter and nitrogen in nourish organs and raise the contribution rates of pre - anthesis stored dry matter and nitrogen in nourish organs to grain weight. Normal sowing date with low or middle sowing density (150 × 10~4/hm~2 and 225 × 10Vhm~2) and late sowing with middle or high sowing density (225 × 10~4/hm~2 and 300 × 10Vhm~2) improve remarkably grain starch and protein contents and grain yield, thus guarantee the simultaneous improvement of grain yield and quality. In this study, to give attention to high yield and high protein content, the appropriate densities with normal sowing date and late sowing date for winter wheat cultivar "Zhoumai 18" are 150 ～225 ×10Vhm~2 and 225 ～ 300 × 10~4/hm~2, respectively.