| The yield of wheat is predominantly contingent upon the source,repository,and their interrelationships.A rational relationship between the source and repository serves as the physiological foundation for the development of wheat yield and quality.In this study,a corpus of 272 wheat varieties and strains bred within the Huang-huai wheat area over the past two decades were employed as materials.Identification and evolutionary analysis of 30 source-sink related traits were conducted to screen for superior germplasm.Based on previous transcriptome sequencing data,we conducted a genome-wide association analysis,identified significant markers for source-sink related traits,and predicted candidate genes.(1)Identification and germplasm screening of wheat source-sink related traits.Phenotypic variation analysis showed that each trait had a significant variation range(3.02%～34.33%).Correlation analysis showed that there was generally a strong positive correlation between sources,sink,and the relationships between them.However,leaf-related traits were mostly significantly negatively correlated with fruiting efficiency and grain number/weight-leaf area ratio.Compared to the control of JM22,a total of 2513 germplasm with excellent single traits were screened.The analysis of source-sink related traits evolution revealed that as time passed,wheat plant height decreased,stem diameter increased,leaf angle,leaf length and leaf area all decreased.spike length decreased,grain number per spike,grain weight per spike,thousand grains weight,and maximum grain number of spikelet all increased.Meanwhile,total spikelet number per spike,fertile spikelet number per spike and sterile spikelet number per spike decreased,while the fruiting efficiency tended to increase,the grain number/weight-leaf area ratio tended to increase.(2)Genome-wide association analysis of source-sink related traits in wheat.A total of2,496 markers(2,276 SNPs and 220 In Dels)were found to be significantly associated with 30 wheat source-sink related traits,distributed across all 21 chromosomes,explaining 4.56% to16.02% of the phenotypic variance.Notably,there are 196 markers that exhibit an explanation rate exceeding 10%.A total of 116 pleiotropic markers were detected,among which a cluster of 40 pleiotropic SNP loci was found in a 7.4 Mb(629.4～636.8 Mb)segment of chromosome7 DL.This region is significantly associated with grain number/weight-leaf area ratio and grain number per spike,and may be an important locus for the grain number/weight-leaf area ratio.(3)Prediction of candidate genes for source-sink related traits.China Spring genome annotation analysis was performed on significant SNP markers detected,and the annotated wheat candidate genes were compared with rice genes to identify 15 candidate genes related to source-sink related traits,including: TraesCS1A02G150900(wax synthesis gene),TraesCS1A02G348700(auxin transport regulatory protein),TraesCS1A02G402400(protein kinase activated by mitosis),TraesCS2D02G456400(calcium-dependent protein kinase),TraesCS3A02G030700(xylan transferase),TraesCS3B02G123800(NPR1-like gene),TraesCS4D02G040200(RING-type E3 ubiquitin ligase),TraesCS5A02G299300(spen-like protein),TraesCS2B02G023800(ethylene receptor),TraesCS3D02G522000(catalytic subunit of magnesium protoporphyrin IX monomethyl ester cyclase),TraesCS5B02G433300(casein kinase),TraesCS6A02G203700(ABC1 kinase),TraesCS6A02G216200(proline-rich protein),TraesCS6D02G378300(early response gene to auxin),TraesCS6D02G382800(β-carotene hydroxylase-like protein). |
