| Sunflower is one of the four major oil crops in the world and has important economic value.However,the main sunflower producing areas in my country,such as Inner Mongolia and Xinjiang,are often due to drought,resulting in a decline in the yield and quality of sunflowers.To this end,this study collected 226 germplasm resources through the seedling simulation drought test,measured plant height,leaf area per plant,SPAD value,root length and other drought-related traits,calculated drought resistance coefficient,comprehensive evaluation D value,etc.Statistical methods were used to evaluate the drought resistance of materials and establish a regression equation to predict the drought resistance of sunflowers.At the same time,the whole genome association analysis was used to unearth the SNPs of drought resistance traits,and to screen out candidate genes related to sunflower drought resistance.These studies provide theoretical support for the identification of sunflower drought resistance and molecular mechanism research,and are of great significance to the genetic improvement of sunflower drought resistance..The results of this study are as follows:1.Root-shoot ratio,root length,root surface area,root volume,plant height,relative leaf water content,SPAD value,leaf area correlation analysis of drought resistance coefficient and comprehensive evaluation D value shows that all 8 indicators can be used as comprehensive evaluation of drought resistance The index further stepwise regression analysis determined that the root length,plant height,and SPAD value had the greatest impact on the D value.The stepwise regression equation was obtained and the drought resistance of sunflower materials was predicted.2.The D value of 8 indexes in the experiment was calculated by drought resistance coefficient,drought resistance membership function value and index weight,and the drought resistance ability of the tested materials was evaluated by the D value.Based on the D value,will be needed for germplasm is divided into five different drought resistance levels.Finally,a total of 15 samples with strong drought resistance,including 175,106 and117,were determined,which could be be used as the main reference materials for sunflower breeding and drought regulation in the future.3.Using SLAF-Seq technology,a total of 934.08 M reads data,and 565668 SLAF tags were located on 17 sunflower chromosomes,among which 243291 were polymorphic.4.By using the mixed linear model,and combining with the high quality 2124143 SNP marker,8 seedling drought traits of sunflower 226 material properties under the condition of drought and contrast analysis of genome-wide association.Sixteen SNP loci with significant correlation with drought resistance traits were found,the leaf area has 1,the root-shoot ratio has 2,the root length has 2,the root surface area has 2,the plant height has 2,the leaf relative water content has 2,the SPAD value has 2,the root volume has 3.5.A total of 22 candidate genes were detected,4 candidate genes related to the root-shoot ratio,5 candidate genes is associated with root length,3 candidate genes related to the root surface area,3 candidate genes related to root volume,2 candidate genes related to plant height,3 candidate genes related to leaf relative water content,3 candidate genes related with the SPAD value,1 candidate gene related to leaf area,one candidate gene related to root volume,plant height and leaf area at the same time.6.RNA88075 and RNA59632 were found in the annotation process of candidate genes,which could be regarded as the relevant focus of drought resistance research in the later stage. |
PDF Full Text Request