Genome-Wide Association Analysis Of Important Agronomic Traits In Sunflower

Sunflower is one of the world’s most important oil crops,and improving sunflower agronomic traits is one of the main goals of sunflower breeding.In order to deeply analyze the molecular genetic mechanism of sunflower agronomic traits,effective molecular markers and genes were mined.In this study,using 113 sunflower inbred line germplasm as research materials,genome-wide association analysis and candidate gene screening and function prediction were carried out on five important agronomic traits of plant height,leaf number,stem thickness,disc diameter and100-grain weight through the SNP marker sites constructed and developed by the research group in the early stage and the phenotypic data obtained from field experiments at two points a year.The main studies are as follows:1.The data analysis results of 113 test materials showed that the variation between the two surfaces was abundant.The coefficient of variation of materials under the conditions of the Chinese Academy of Agricultural Sciences ranged from14.5%～40.5%,the coefficient of variation of materials under the condition of Qixudai was 12.6%～40.8%,and the average coefficient of variation ranged from 11.3%～37.8%.The analysis of the mean correlation between the Chinese Academy of Agricultural Sciences,Qifutai and the two places showed that the plant height was positively correlated with the number of leaves and stem thickness.The number of leaves was positively correlated with plant height,stem thickness,disc diameter and 100 grain weight.Stem thickness was positively correlated with plant height,leaf number,disc diameter and 100-grain weight.The disc diameter was positively correlated with the number of blades and the weight of 100 grains.The weight of 100 grains was positively correlated with the number of leaves,stem thickness and disk diameter.2.Combined with the 81,146 SNP markers developed by association population determination in the early stage,genome-wide association analysis was carried out on113 materials and 5 agronomic traits of sunflower under two environmental conditions,and a total of 30 SNP sites with significant association with agronomic traits were detected,located on chromosomes 2,7,8,9,10 and 16.No significant SNP sites were detected on other chromosomes,among which 16 SNPs related to stem thickness,9SNPs related to leaf number,and 10 SNPs related to 100 grain weight.3.A total of 24 candidate genes were detected,8 related to disk diameter,9 related to 100 grain weight,and 7 related to stem thickness,which can regulate the absorption of phosphorus and sulfur nutrients in the soil by the root system,which can improve crop yield,improve crop tolerance to sulfur deficiency stress,affect plant aging,and regulate growth and development.4.LOC110884070、LOC1100880793、LOC110866938、LOC110884081、LOC110880808,and LOC110884082 were found to be key candidate genes for later sunf lower agronomic trait improvement research.