摘要
【目的】本研究基于气候室模拟温度日变化特征,旨在探讨氮素对高温、干旱及复合胁迫下冬小麦地上干物质重、氮积累与分配、氮代谢相关酶活性、蛋白质含量、产量及水氮利用效率的影响。【方法】基于人工气候室开展冬小麦盆栽试验,以小偃22号为试验材料,采用裂-裂区随机完全区组设计,以2个温度处理(高温:H;适宜温度:S)为主区,以2个水分水平(干旱:D;充分供水:F)为裂区,3个施氮水平(低氮:N_(1);中氮:N_(2);高氮:N_(3))为裂-裂区,研究冬小麦生长生理特性、产量及水氮利用效率对高温干旱胁迫及各施氮量的响应特征。【结果】高温、干旱及复合胁迫导致地上总干物质重(ADW)和氮积累量(ANA)降低。在成熟期,高温干旱复合胁迫(HD)和干旱胁迫(SD)下N_(3)处理ANA分别较N_(1)处理增加7.26%和6.82%。高温、干旱及复合胁迫提高小麦花前氮素对籽粒贡献率(NRR),HD胁迫各施氮处理NRR均值较对照(SF)增加达38.21%,施氮量的增加扩大这种增加效应。高温、干旱及复合胁迫导致成熟期穗氮分配率降低,特别是复合胁迫。暴露于高温、干旱及复合胁迫下籽粒蛋白质产量(PY)降低,干旱胁迫(7.37%)各施氮处理PY均值较高温胁迫(3.94%)降低更多,无论单一或复合胁迫下籽粒PY均在N_(2)处理下显著增加。此外,单一的干旱和高温胁迫下降低的谷氨酰胺合成酶(GS)和硝酸还原酶(NR)活性在N_(2)处理下显著增加,复合胁迫N_(1)处理NR和GS活性分别较N_(3)处理提高23.81%和23.07%。与对照相比,干旱胁迫各施氮处理穗粒数、千粒重和产量均值的降幅均高于高温胁迫,N_(2)处理对高温和干旱胁迫下这些参数存在明显正向调控,产量水分利用效率(WUE_(g))和生物量水分利用效率(WUE_(b))在N_(2)处理下得到明显改善。充分供水+N_(2)处理籽粒(NUE_(g))分别较低干旱和复合胁迫N_(3)处理提高19.09%和19.44%,表明在水分充足条件下中氮能有效地缓解干旱和高温胁迫下籽粒氮利用效率的降低。NUE_(g)和NUE_(b)的提高可能归因于合理氮肥调控下增加的GS和NR活性。主成分分析表明胁迫条件下小麦千粒重和ADW与产量的关系更紧密。【结论】高温和干旱胁迫的综合效应比单一胁迫对小麦危害更大。在单一高温和干旱胁迫下,适量增加氮输入能增加氮代谢酶活性并维持更高氮代谢能力,提高籽粒氮积累量及蛋白质产量,将更有利于提高产量及水氮利用效率。然而在花后遭遇高温干旱复合胁迫时,相比低施氮量,增加施氮对小麦产量形成及水氮的吸收利用均产生一定抑制作用,应适当减少氮肥用量。
【Objective】The diurnal variation of temperature was simulated based on the growth chamber,this study aimed to investigate the effects of nitrogen(N)on dry matter accumulation,N accumulation and distribution,activities of N metabolism-related enzymes,protein content,yield,and water and N use efficiency of winter wheat plants under heat,drought and combined stress.【Method】The experiments were carried out based on growth chambers with Xiaoyan 22 as test material.The experiment consisted of three blocks,in which two temperature treatments(high temperature:H;suitable temperature:S)were assigned as the main plot,two watering treatments(drought:D;sufficient water supply:F)were arranged split-plot,and three N supply levels(low N:N_(1);medium N:N_(2);high N:N_(3))were arranged split-split plot to form a completely randomized block design to investigate the response of the growth and physiological characteristics,yield,and water and N use efficiency in wheat plants to heat,drought stress and different N applications.【Result】Heat,drought and combined stress resulted in the decrease in ADW(aboveground dry weight)and ANA(aboveground nitrogen accumulation).At maturity,the ANA of N_(3) supply under HD and SD was higher 7.26%and 6.82%than that under N_(1) supply,respectively.Heat,drought and combined stress resulted in the increase in NRR,and the average NRR of three N supplies under HD increased by 38.21%compared with the control,while increasing N supply further expanded this increasing effect.Heat,drought and combined stress led to decrease in N distribution rate of panicle at maturity,especially combined stress.PY decreased significantly when exposed to heat,drought and combined stress.Compared with the control,the decrease of PY under drought stress conditions(7.37%)was more obvious than that under heat stress conditions(3.94%).Under individual and combined stress treatments,PY was significantly increased under N_(2) supply.Furthermore,GS and NR activities decreased under individual heat and drought stress,which were significantly increased under regulation of N_(2) supply.The NR and GS activities of N_(1) supply under HD were 23.81%and 23.07%higher than that of N_(3) supply,respectively.Compared with the control,the reduction in grain number per spike,1000 grain weight and yield under drought stress conditions was greater than that under heat stress.N_(2) supply had an obvious positive effect on these parameters of the two stress treatments,and WUE_(g) and WUE_(b) were significantly improved under N_(2) supply.Adequate water supply under N_(2) had 19.09%and 19.44%higher NUE_(g) than drought and combined stress under N_(3),respectively.This indicates adequate water supply under medium N could effectively alleviate the decrease of NUE_(g) induced by drought and heat stress.The increase of NUE_(g) and NUE_(b) might be attributed to increase of GS and NR activities by appropriate N supply.Principal component analysis indicated that TGW and ADW of wheat were more closely related to yield under stresses conditions.【Conclusion】The results showed that combined effect of drought and heat stress was more detrimental than individual stresses.Under individual heat and drought stress,an appropriate N supply could increase the activities of N metabolism enzymes and maintain higher N metabolism capacity,improve GNA and PY,and would be much more beneficial to increasing grain yield,water and N use efficiency in wheat production.However,when wheat was subjected to the combined stress after anthesis,compared with low N supply,increasing N supply had a restrictive effect on wheat yield formation as well as water and N utilization capacity,while N supply should be appropriately reduced.
作者
汝晨
胡笑涛
吕梦薇
陈滇豫
王文娥
宋天媛
RU Chen;HU XiaoTao;LÜMengWei;CHEN DianYu;WANG WenE;SONG TianYuan(Northwest A&F University/Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas,Ministry of Education,Yangling 712100,Shaanxi)
出处
《中国农业科学》
CAS
CSCD
北大核心
2022年第17期3303-3320,共18页
Scientia Agricultura Sinica
基金
国家重点研发计划(2017YFD0201508)
国家自然科学基金(52079113)。
关键词
氮肥管理
高温和干旱胁迫
氮积累
蛋白质含量
产量
水氮利用效率
nitrogen management
heat and drought stress
nitrogen accumulation
protein content
grain yield
water and nitrogen use efficiency
