Construction Of High-Density Genetic Map And QTL Mapping Of Fruit Size And Sugar-Acid Traits On‘JMS2’ × ‘Jiaocheng 5’ Jujuba Hybrid Progeny

The construction of high-density genetic map is the basis of molecular assisted breeding research,but the research on genetic map construction and molecular marker assisted selection of jujube is obviously lagging behind other fruit trees.In this study.140 materials from ‘JMS2’ and‘Jiao Cheng 5’ hybrids F1,and use WGS(Whole Genome Sequencing)to develop SNP and In Del mark to construct a high-dersity genetic map of jujube trees.There are 14 fruit size and sugar-acid traits were investigated for two consecutive years,and QTL mapping was performed.The main conclusions are as follows:1.A high-density genetic map was constructed besed on Whole Genome Sequencing Technology and reference to ‘Dongzao’ genome.The map contains 8684 bin markers,the average map distance is 0.20 c M from the total map distance as 1713.22 c M.2.The variation coefficients of 14 fruit size and sugar acid traits investigated for two consecutive years were between 12.48 % and 41.75 %,indicating that these traits were widely separated among offspring individuals.The frequency distribution of the investigated traits conformed to normal distribution,which was a quantitative trait regulated by multiple genes.3.The interval mapping method of R/qtl was used for QTL mapping.With LOD value ≥ 3.0as the critical value of QTL effect.104 QTLs were detected in 14 traits of fruit,including 57 QTLs for fruit size,17 QTLs for fruit sugar components,and 30 QTLs for fruit acid components.The number of QTLs for single fruit weight was 14,11 QTLs for fruit length,21 QTLs for fruit diameter,11 QTLs for fruit shape index;6 QTLs for fructose,7 QTLs for glucose,and 4 QTLs for sucrose;there were 4 QTLs for oxalic acid,7 QTLs for tartaric acid,6 QTLs for quinic acid,2 QTLs for malic acid,1 QTL for citric acid,7 QTLs for fumaric acid and 3 QTLs for ascorbic acid.4.There were 23 genetic regions with the same interval in QTL for different traits.Among them,11 QTLs overlapping regions of fruit diameter and single fruit weight;three overlapping QTLs for fruit length and single fruit weight;two overlapping QTLs for fruit transverse diameter,fruit longitudinal diameter and single fruit weight;one overlapping QTLs for fruit length and fruit shape indext;four overlapping QTLs for fructose and glcose;one overlapping QTLs for fructose,glucose and sucrose;one overlapping QTLs for malic acid and tartaric acid.