QTL Mapping Of Important Agronomic Traits In Barley(Hordeum Vulgare L.)

Barley(Hordeum vulgare L.)can be used as raw material for beer industry,feed and food.It has the advantages of high tolerance and early maturity,and is widely planted all over the world.Agronomic traits are the basis of barley population quality,which affect the yield,quality and resistance of barley.Research on the genetics of agronomic traits and QTL mapping chould help the selection of agronomic traits and the breeding of high-quality,high-yield,and multi-resistant barley varieties.In this study,the natural population and a DH population of barley were planted in Yangzhou and Yancheng in 2018 and 2019.After maturity,seven agronomic traits including the plant height,spike length,internode length under spike,kernel number per spike,spike number per plant,dry weight per plant and kernel weight per plant were investigated and the performance,differences and correlation of each trait were analyzed.Genome-wide association studies and QTL linkage mapping analysis were performed for the 7 important agronomic traits.The main results are as follows:1.Abundant genetic variations in the seven traits of the natural population,including spike length,internode length under spike,kernel number per spike,spike number per plant,dry weight per plant and kernel weight per plant were observed in both two locations.The range of plant height,spike length,internode length,kernel number per spike,spike number per plant,dry weight per plant,kernel weight per plant was 50.91cm-144.43cm,4.37cm-12.35cm,21.34cm-51.65cm,26.40-111.00,6.45-31.67,15.90g-98.07g,4.65g-43.42g,respectively.The performance of each trait in different locations and the BLUPs values of the two locations showed a normal or approximately normal distribution.2.The plant height was significantly correlated with the other six traits of barley;The internode length under spike was significantly positively correlated with dry weight per plant;The kernel number per spike was significantly negatively correlated with spike number per plant and was significantly positively correlated with dry weight per plant;The spike number per plant was significantly positively correlated with dry weight per plant and kernel weight per plant;The dry weight per plant was significantly positively correlated with kernel weight per plant.3.The plant height,spike length,internode length under spike,kernel number per spike,spike number per plant,dry weight per plant,kernel weight per plant in natural population and DH population were almost significant or extremely significant differences between location,genotype,environment and genotype interaction.And their heritabilities were 78.98%,89.31%,84.50%,46.80%,54.46%,44.83%,55.61%,respectively.4.In this study,a total of 36 SNP markers were found to be significantly associated with agronomic traits in barley by genome-wide association analysis,of which 16 SNP markers were highly associated with agronomic traits.Totally 22 QTL controlling barley serven agronomic traits were detected by QTL mapping analysis,of which 9 QTL contributed more than 10.00%contribution rate to the traits.A QTL controlling the kernel weight per plant were co-located at 60cM on 3H chromosome by genome wide association analysis and QTL analysis.