How delaying post-silking senescence in lower leaves of maize plants increases carbon and nitrogen accumulation and grain yield

作     者：Rongfa Li Dandan Hu Hao Ren Qinglong Yang Shuting Dong Jiwang Zhang Bin Zhao Peng Liu Rongfa Li;Dandan Hu;Hao Ren;Qinglong Yang;Shuting Dong;Jiwang Zhang;Bin Zhao;Peng Liu

作者机构：State Key Laboratory of Crop Biology/College of AgronomyShandong Agricultural UniversityTai’an 271018ShandongChina 

出 版 物：《The Crop Journal》 (作物学报（英文版）)

年 卷 期：2022年第10卷第3期

页      面：853-863页

核心收录：

学科分类：09[农学] 0901[农学-作物学] 

基　　金：financially the National Key Research and Development Program of China(2016YFD0300106,2018YFD0300603) the Shandong Modern Agricultural Technology&Industry System(SDAIT-02-08) 

主　　题：13C-Photosynthate distribution Nitrogen uptake Maize grain yield Delaying lower leaf senescence Post-silking 

摘      要：Planting maize at high densities leads to early leaf senescence,and the resulting reduction in the number of lower leaves affects the plant’s root function and lowers its grain ***,the nature of the process by which lower leaf senescence affects biomass accumulation and grain yield formation in maize is not *** study aimed to shed light on how these factors are related by investigating the effects of the plant growth regulator 6-benzyladenine(6-BA)on the senescence of lower leaves of maize *** two maize cultivars planted at densities of 67,500(low density,LD)and 90,000(high density,HD)plants ha^(-1),plants treated with 6-BA maintained a high green leaf area index(LAI)longer than control(CK)plants,enabling them to maintain a higher photosynthetic rate for a longer period of time and produce more biomass before reaching physiological *** the lower leaves of maize plants with a 6-BA solution increased the distribution of;C-photosynthates to their roots,lower leaves and bracts,a result that can be ascribed to a decreased retention of;C-photosynthates in the stem and *** both seasons of the experiment,maize plants treated with 6-BA accumulated more N in grain and maintained a higher N content in roots and leaves,especially in lower leaves,than *** C assimilation in the lower leaves may explain why N uptake in plants subjected to the 6-BA treatment exceeded that in CK plants and why both photosynthesis rate and dry matter accumulation were maintained throughout grain *** results suggest that a suitable distribution of C and N in leaves post-silking may maintain plant root function,increase N use efficiency,maximize the duration of high LAI,and increase grain yield.