水氮互作对春小麦干物质积累、转运与灌浆特性的影响

Effects of water-nitrogen interaction on dry matter accumulation,transport and grain filling characteristics of spring wheat

为探究焉耆地区高产滴灌春小麦干物质积累、转运与灌浆特性及其对水氮互作的响应机制,明确该地区滴灌春小麦的水氮施用量,以‘新春38号’和‘新春45号’春小麦为试验材料,采用裂区设计,设置灌溉处理为主区,包括亏缺灌溉(W_(1),4500 m^(3)·hm^(-2))和适宜灌溉(W_(2),6000 m^(3)·hm^(-2));施氮处理为副区,包括0(N 0)、300 kg·hm^(-2)(N_(1))、400 kg·hm^(-2)(N 2),比较分析高产滴灌春小麦花后叶片和茎鞘的干物质积累与籽粒灌浆特性。结果表明:随施氮量增加,两品种茎鞘和叶片的干物质积累量、转移量、转移率和粒重均先增加后降低,并均以W_(2)N_(1)处理最佳,贡献率则以W_(1)N_(1)处理最佳。两品种快速增长期结束时间(t_(2))、快速增长期持续时间(t_(2)-t_(1))、平均灌浆速率(V mean)、最大灌浆速率(V max)均随施氮量的增加呈先增加后降低,而快速增长期时间(t_(1))为先降低后增加,最大灌浆速率时间(t max)则持续下降。相关性分析表明,茎鞘、叶片的转移量、转移率、贡献率、t_(2)、t_(2)-t_(1)、V_(max)、V_(mean)与粒重存在显著正相关关系,且两品种的粒重与平均灌浆速率的直接通径系数分别为0.5354和0.5173,与灌浆持续时间的直接通径系数为0.6752和0.6249,表明灌浆持续时间对粒重的影响程度大于平均灌浆速率。在焉耆地区滴灌春小麦生产中,以W_(2)N_(1)处理(灌水6000 m^(3)·hm^(-2)+施氮300 kg·hm^(-2))茎鞘和叶片的干物质积累量、转运率表现最佳,故推荐其为焉耆地区合理的水氮供给模式。

In order to explore the dry matter accumulation,transport and grain filling characteristics of high-yield drip irrigated spring wheat in Yanqi area and its response mechanism to water and nitrogen interaction and clarify the water and nitrogen application rate of drip irrigated spring wheat in this area,‘Xinchun 38’and‘Xinchun 45’spring wheats were used as experimental materials.The split-zone design was employed,with the main irrigation treatments including deficit irrigation(W1:4500 m^(3)·hm^(-2))and optimal irrigation(W2:6000 m^(3)·hm^(-2)).Nitrogen application served as the secondary treatment,with levels of 0(N0),300 kg·hm^(-2)(N1),and 400 kg·hm^(-2)(N2).The dry matter accumulation and grain filling characteristics of leaves and stem sheaths in high-yield drip-irrigated spring wheat after flowering were compared and analyzed.The results showed that with the increase of nitrogen application rate,the dry matter accumulation,transfer amount,transfer rate and grain weight of stem sheath and leaf of the two varieties increased first and then decreased,and all of them were treated with W_(2)N_(1) as the best,and the contribution rate was the best with W_(1)N_(1).The end time of the rapid growth period(t_(2)),the duration of the rapid growth period(t_(2)-t_(1)),the average grain filling rate(V mean)and the maximum grain filling rate(V max)of the two varieties increased first and then decreased with the increase of nitrogen application rate,while the time of the rapid growth period(t_(1))decreased first and then increased,and the maximum grain filling rate time(t max)continued to decrease.Correlation analysis showed that there was a significant positive correlation between stem sheath and leaf transfer amount,transfer rate,contribution rate,t_(2),t_(2)-t_(1),V_(max) and V_(mean) and grain weight,and the direct diameter coefficients between grain weight and average filling rate were 0.5354 and 0.5173,respectively,and 0.6752 and 0.6249,respectively,indicating that the effect of grain filling duration on grain weight was greater than that of average grain filling rate.In the production of drip irrigation spring wheat in Yanqi area,the dry matter accumulation and transport rate of stem sheaths and leaf treated of W_(2)N_(1)(irrigation 6000 m^(3)·hm^(-2)+nitrogen application 300 kg·hm^(-2))were the best,so it is recommended as a reasonable water and nitrogen supply mode in Yanqi area.