关键词: 大豆, 叶绿素含量, 群体结构, 全基因组关联分析, 单倍型分析

Abstract: Chlorophyll is a key pigment involved in photosynthesis and influences plant photosynthetic efficiency and yield. However，the genetic basis underlying chlorophyll biosynthesis and regulation remains poorly understood. To dissect the genetic basis of chlorophyll content in soybean leaves，we used 563 accessions of a soybean natural population and evaluated their chlorophyll content at the flowering stage across three locations［Xinxiang City（Yuanyang County），Luohe City，and Xinyang City in Henan Province］.Based on genotype data from the GenoBaits Soybean 10K Panel，STRUCTURE analysis and phylogenetic tree analysis revealed significant subpopulation strucure（K=5）.In the subsequent genome⁃wide association study，four analytical models were constructed to identify significant single nucleotide polymorphism（SNP）loci.As a result，MLM，BLINK，MLMM and FarmCPU identified 15,9,5 and 4 significant loci，respectively.Among these，Gm04623 on chromosome 2 showed the strongest effect and was stably detected in all four models，explaining 9.77%—13.81% of the phenotypic variation.Through functional annotation and expression profile analysis of genes within the 300 kb region flanking Gm04623，we inferred that Glyma. 02g305400 was involved in regulating chlorophyll content in soybean leaves.This gene encoded a chlorophyll a/b binding protein that formed a complex with chlorophyll to capture light energy for photosynthesis. Haplotype analysis of the linkage block harboring this gene identified four haplotypes，among which H001 showed the highest chlorophyll content and significant differences from the others. This study detected major associated loci Gm04623 and the key candidate gene Glyma.02g305400 controlling chlorophyll content in soybean leaves，enriching the genetic understanding of this trait. The superior haplotype H001 with high chlorophyll content was also identified，providing genetic resources and theoretical support for molecular breeding of soybeans with high photosynthetic efficiency.

Key words: Soybean, Chlorophyll content, Population structure, Genome?wide association analysis, Haplotype analysis