立体匀播和密度对冬小麦光合、干物质积累分配及产量的影响

Effect of Uniforming Sowing Pattern and Planting Density on Photosynthesis,Dry Matter Accumulation and Distribution and Yield of Winter Wheat

为给小麦立体匀播栽培推广提供理论依据,选用小麦品种新冬22号和新冬46号为供试材料,采用裂区设计,主区种植方式设立体匀播和常规条播2个处理,副区种植密度设150万株·hm^(-2)(D150)、225万株·hm^(-2)(D225)、300万株·hm^(-2)(D300)和375万株·hm^(-2)(D375)4个处理,研究了种植方式和密度对冬小麦光合、干物质积累与分配、产量及其构成因素的影响。结果表明,与常规条播比较,立体匀播方式下小麦群体生育后期中、下部叶的LAI、SPAD值和净光合速率显著提高;植株重、干物质转运量、干物质转运效率和干物质转运对籽粒产量贡献率增大,而植株成熟期营养器官干物质分配率降低;随着种植密度增大,茎鞘干物质分配率上升,叶片干物质分配率减小,而颖壳及穗轴、籽粒干物质分配率则无显著变化。与常规条播相比,立体匀播方式下新冬22号和新冬46号主茎穗粒重平均降低7.95%和4.43%,而分蘖穗粒重平均提高11.54%和5.06%,穗数显著提高(17.31%和17.68%),产量提高6.40%和9.84%,以D225处理产量最高;穗粒数分别降低2.23%和1.71%,千粒重分别降低4.38%和4.54%。由此可知,立体匀播方式提高了小麦群体生育后期中、下部叶片叶面积指数和净光合速率,增大了植株干物质积累量,促进了营养器官干物质向分蘖穗籽粒中转运,并主要通过增加群体穗数和分蘖穗穗粒重提高产量;最佳的种植密度为225万株·hm^(-2)。

In order to provide theoretical basis for uniforming sowing in wheat cultivation,the research was carried out to study the effect of different planting patterns and density on the photosynthesis,dry matter accumulation and distribution,and yield and its components.Two wheat varieties Xindong 22 and Xindong 46 were used as materials.The split plot design was used;the main plot was planting pattern at two levels:uniforming and drilling sowing,and subplot were four planting density levels at 1.50×106,2.25×106,3.00×106 and 3.75×106 plants·hm^(-2),designated as D150,D225,D300 and D375.The results showed that the LAI,SPAD value and the net photosynthetic rate of the lower leaves at the late growth stage of wheat population were significantly improved under uniforming sowing pattern,compared with those under the conventional drilling pattern.The plant weight,dry matter transport capacity,dry matter transport rate and contribution rate of dry matter transport to grain yield increased,while the dry matter allocation rate of vegetative organs decreased at plant maturity.With the increase of planting density,dry matter distribution of stem and sheath increased,yet the dry matter allocation rate of glume,rachis and grain had no significant change.Compared with conventional drilling sowing,the grain weight per spike of main stem of Xindong 22 and Xindong 46 decreased by 7.95%and 4.43%,while the tillering panicle increased by 11.54%and 5.06%;the number of panicles increased significantly(17.31%and 17.68%),and the yield increased by 6.40%and 9.84%,and the yield of D225 was the highest;the number of grains per spike decreased by 2.23%and 1.71%,and the 1000-grain weight decreased by 4.38%and 4.54%,respectively.The results showed that the uniforming sowing pattern improved leaf area index and net rate in the middle and lower parts of wheat population at the late growth stage,increased the dry matter accumulation of plant,promoted the translocation of dry matter from vegetative organs to tiller grains,and increased the yield mainly by increasing the number of panicles and grain weight.The optimal planting density was 2.25×106 plants·hm^(-2).