Effect of delayed sowing on grain number, grain weight, and protein concentration of wheat grains at specific positions within spikes  

作　　者：CHU Jin-peng GUO Xin-hu ZHENG Fei-na ZHANG Xiu DAI Xing-long HE Ming-rong 

机构地区：[1]State Key Laboratory of Crop Biology/Key Laboratory of Crop Ecophysiology and Farming System,Ministry of Agriculture and Rural Affairs/Agronomy College,Shandong Agricultural University,Tai'an 271018,P.R.China

出　　处：《Journal of Integrative Agriculture》2023年第8期2359-2369,共11页农业科学学报（英文版）

基　　金：Financial support was received from the National Key Research and Development Program of China(2016YFD0300403 and 2017YFD0201705)。

摘　　要：Delays in sowing have significant effects on the grain yield,yield components,and grain protein concentrations of winter wheat.However,little is known about how delayed sowing affects these characteristics at different positions in the wheat spikes.In this study,the effects of sowing date were investigated in a winter wheat cultivar,Shannong 30,which was sown in 2019 and 2020 on October 8(normal sowing)and October 22(late sowing)under field conditions.Delayed sowing increased the partitioning of ^(13)C-assimilates to spikes,particularly to florets at the apical section of a spike and those occupying distal positions on the same spikelet.Consequently,the increase in grain number was the greatest for the apical sections,followed by the basal and central sections.No significant differences were observed between sowing dates in the superior grain number in the basal and central sections,while the number in apical sections was significantly different.The number of inferior grains in each section also increased substantially in response to delayed sowing.The average grain weights in all sections remained unchanged under delayed sowing because there were parallel increases in grain number and ^(13)C-assimilate partitioning to grains at specific positions in the spikes.Increases in grain number m^(–2) resulted in reduced grain protein concentrations as the limited nitrogen supply was diluted into more grains.Delayed sowing caused the greatest reduction in grain protein concentration in the basal sections,followed by the central and apical sections.No significant differences in the reduction of the grain protein concentration were observed between the inferior and superior grains under delayed sowing.In conclusion,a 2-week delay in sowing improved grain yield through increased grain number per spike,which originated principally from an increased grain number in the apical sections of spikes and in distal positions on the same spikelet.However,grain protein concentrations declined in each section because of the increased

关 键 词：WHEAT delay in sowing grain number grain weight grain protein concentration 

分 类 号：S512.1[农业科学—作物学]