Differences between two wheat genotypes in the development of floret primordia and contents of pigments and hormones  

作　　者：Liangyun Wen Yaqun Liu Bingjin Zhou Wan Sun Xuechen Xiao Zhimin Wang Zhencai Sun Zhen Zhang Yinghua Zhang 

机构地区：[1]College of Agronomy and Biotechnology,China Agricultural University,Beijing 100193,China [2]Engineering Technology Research Center for Agriculture in Low Plain Areas,Cangzhou 061800,Hebei,China

出　　处：《The Crop Journal》2024年第4期1196-1207,共12页作物学报（英文版）

基　　金：funded by the Scientific and Technological Innovation Team Project of Seed Industry for Saline-alkali Tolerant Crop in Hebei Province(23327501D);the National Key Research and Development Program of China(2022YFD2300802,2022YFD1900703);the China Agriculture Research System(CARS-3).

摘　　要：Promoting more floret primordia within a spike to acquire fertile potential during the differentiation and pre-dimorphism phases is critical for increasing the number of fertile florets per spike(NFFs).However,it is yet unknown the physiological mechanism regulating the complex and dynamic process.This study aimed to clarify how intra-spike hormones,pigments,and assimilates coordinate with each other to regulate spike morphology and then floret primordia development.A two-year field experiment was conducted with two winter wheat genotypes:N50(big-spike with greater NFFs)and SM22(mediumspike with fewer NFFs).We monitored high temporal and spatial-resolution changes in the number and morphology of floret primordia within a spike,as well as in intra-spike hormones,pigments,and assimilates.Our results revealed that the big-spike genotype had more NFFs than the medium-spike genotype,not only because they had more spikelets,but also because they had greater NFFs mainly at central spikelets.More floret primordia at central spikelets had sufficient time to develop and acquire fertile potential during the differentiation phase(167-176 d after sowing,DAS)and the pre-dimorphism phase(179 DAS)for the big-spike genotype than the medium-spike genotype.Floret primordia with fertile morphology during the pre-dimorphism phase always developed into fertile florets during the dimorphism phase.Those early-developed floret primordia most proximal and intermediate to the rachis in the big-spike genotype developed faster than the medium-spike genotype.Correspondingly,the spike dry matter and pigments(chlorophyll a,chlorophyll b,carotene,and carotenoids)content during 170-182 DAS,auxin(IAA)and cytokinin(CTK)content on 167 DAS were significantly higher in the big-spike genotype than in the medium-spike genotype,while jasmonic acid(JA)content was significantly lower in the big-spike genotype compared to the medium-spike genotype during 167-182 DAS.Since the significant differences in intra-spike hormone content of the two genotypes appear

关 键 词：Fertile florets Floret primordia development Intra-spike hormones Jasmonic acid Photosynthetic pigments 

分 类 号：S512.1[农业科学—作物学]