播期和密度对冬小麦开花后干物质转运及灌浆特征参数的影响

Effects of seeding date and density on dry matter transport and filling characteristic parameters of winter wheat after anthesis

以周麦22为试验材料,采用裂区试验,研究播期(B1:10月5日;B2:10月10日;B3:10月15日;B4:10月20日)和播种密度(M1:1 hm^(2)1.2×10^(6)株;M2:1 hm^(2)2.7×10^(6)株;M3:1 hm^(2)4.2×10^(6)株)对籽粒灌浆和物质转运的影响。结果表明,(1)播期和播量均对灌浆特征参数产生显著影响,播期主要影响灌浆速率,而密度主要影响灌浆持续时间。(2)冬小麦花后干物质积累动态符合一元三次多项式Y=b+b_(1)x+b_(2)x^(2)+b_(3)x^(3)(Y为营养器官干物质质量,b、b_(1)、b_(2)、b_(3)为系数,x为开花后天数),开花后8~10 d植株营养器官干物质积累量达到最大值;播期提前可显著提高冬小麦单株干物质积累量,但随种植密度增加,冬小麦单株干物质积累量则迅速降低。(3)开花后冬小麦营养器官干物质转运量对籽粒产量的贡献率为43.07%~70.11%。渐增期籽粒灌浆以光合作用产物为主,快增期、缓增期籽粒灌浆养分来源以营养器官干物质转运为主。播期主要影响灌浆速率、最大灌浆达到时间、快增期持续时间和缓增期持续时间;密度主要影响千粒质量、总灌浆持续时间、渐增期持续时间和各时期籽粒增质量;播期和密度互作效应主要影响平均灌浆速率和渐增期持续时间。

Influence of seeding dates(B1~B4:October 5,October 10,October 15,October 20)and seeding densities(M1~M3:1.2×10^(6) strains/hm^(2),2.7×10^(6) strains/hm^(2),4.2×10^(6)strains/hm^(2))on grain filling and material transport were studied by split plot test,using Zhoumai 22 as the test material.The results showed that,firstly,seeding date and seeding density both influenced grain filling characteristic parameters obviously,the seeding date mainly affected the filling rate,while the seeding density mainly affected the filling duration.Secondly,dynamics of dry matter accumulation after anthesis of winter wheat accorded with univariate cubic polynomial:Y=b+b_(1)x+b_(2)x^(2)+b_(3)x^(3)(Y represented dry matter mass in vegetative organs,b,b_(1),b_(2),b_(3)represented coefficients,x represented days after anthesis).The dry matter accumulation in vegetative organs reached the maximum at 8-10 days after anthesis.Advance of the seeding date could significantly increase the dry matter accumulation per plant of winter wheat,but with the increase of planting density,the dry matter accumulation per plant of winter wheat decreased rapidly.Thirdly,the contribution rate of dry matter transport quantity in vegetative organs of winter wheat after anthesis to grain yield was 43.07%-70.11%.Products of the photosynthesis was the main nutrient source of grain filling in the slightly increasing stage,and the dry matter transport of vegetative organs was the main nutrient source of grain filling in the fast increasing stage and slowly increasing stage.Seeding date mainly influences filling rate,arrival time of maximum filling,duration of fast increasing period and duration of slightly increasing period.Seeding density mainly influences thousand-grain weight,total filling duration,duration of slightly increasing stage and grain weight increase at each stage.The interaction effect of seeding date and seeding density mainly affects the average filling rate and the duration of slightly increasing period.