| Plant height is an important morphological trait of soybean,which has an important influence on soybean growth and yield formation.At the same time,plant height is a typical quantitative trait,controlled by a variety of genes and has continuous variati on and is greatly affected by the environment.It is of great significance to study soybean plant height traits and analyze its genetic basis for molecular marker-assisted selection of soybean breeding.In the early stage,we constructed a RIL6013 population consisting of 156 families derived from “Dongnong L13” and “Henong 60”.In this study,based on this RIL population,the SSR marker map was used to apply interval mapping(IM)and complete interval mapping(ICIM),and the plant height phenotypic data of soybean were used to map the plant height QTL in 9 environments at 4 locations over 6 years.Taking the physical map of Williams 82 as the reference background,according to the physical position of QTL,the meta-analysis was carried out by integrating the QTLs of plant height traits of the predecessors and the location of this study.At t he same time,combined with SNP markers obtained by Soy SNP660 K Beadchip,five multi-locus genome-wide association study models mr MLM,FASTmr MLM,FASTmr EMMA,p LARm EB and ISIS EM-BLASSO were used to perform GWAS analysis with LOD value> 3 as the threshold.Then,combining the QTN obtained by Meta-QTL and GWAS mapping,gene annotation was performed on the co-located QTN genome candidate segments to predict candidate genes that control soybean plant height,and analyze their functions.The following results:(1)The generalized heritability in each environment is between 74.30% and 89.78%,indicating that plant height is mainly affected by genotypes.At the same time,the plant height showed a strong transgressive inheritancein in various environments and was suitable for QTL mapping.(2)A total of 48 QTLs were detected,of which three QTLs(q PH-C1-1,q PH-M-1,q PHF-1,q PH-L-1)explaining >10% phenotypic variation.Multi-method and multi-environment located 9 significant QTLs.Later,the plant height QTLs that were located by previous people were collected and compared with them,and 27 QTLs overlap with QTLs that were previously mapped in the genomic region,which of 21 QTLs was new discovered.(3)The 72 plant height QTLs detected in this study were combined with the 159 plant height QTLs detected in previous studies,and meta-analysis was performed to obtain 49 Meta-QTLs distributed on 18 linkage groups with a confidence interval of 0Mb-24.52 Mb.The average genetic contribution rate is 1.71%-32.02%,and the original QTL of each Meta-QTL is between 2-16.(4)After quality screening,MAF>5%,and the maximum missing sites per SNP was <10%,and genotype data of 54,836 non-redundant single nucleotide polymorphisms were generated.The population was divided into two subgroups containing 64 and 75 families,respectively.The linkage disequilibrium attenuation curve gives an attenuation distance of 200 Kb.10 QTNs were located by five methods,and 3 QTNs were located under multiple methods.Among them,4 QTN s overlapped with the previously located Meta-QTL.(5)We searched for potential candidate genes within 100-kb intervals on both sides of four QTNs,a total of 57 genes were searched for candidate genes,of which 5 candidate genes related to soybean plant height growth were predicted.Through the ensemble plant website,we searched for homologous genes of 57 genes in Arabidopsis thaliana,and found 18 homologous genes,4 of which may be related to plant height growth,which will help our multi-gene regulatory network for soybean plant height.There is also an understanding of genetic mechanisms,which can bet ter help soybean high-yield breeding.This study greatly enriched the QTL for soybean plant height traits,and discovered candidate genes related to plant height growth and development,which played a supporting role in marker-assisted selection of soybean breeding. |
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