| Hawthorn（Crataegus spp.）is a plant of the genus Crataegus in the Rosaceae,Apple subfamily,it is an important fruit tree resource with both medicine and food.Flavonoids,as one of the main active ingredients in hawthorn,have been proved to have a variety of important pharmacological activities by a large number of studies.This study took flavonoids in hawthorn as the research object,based on the studied of the dynamic changes of flavonoid content in hawthorn leaves during the growing season,aiming to help people determine the best leaves harvesting time.And through the QTL for hawthorn leaf flavonoid content and the QTL of hawthorn leaf flavonoid content,lay the foundation for future molecular marker-assisted breeding of hawthorn and the location and cloning of genes that related to flavonoids content in the future.In this experiment,High Performance Liquid Chromatography（HPLC）was used to analyze the dynamic changes of hawthorn leaf flavonoid content during the growing season.Two content peak periods and one hawthorn maturity period were selected as three key periods,the established high-density genetic map of hawthorn,Map QTL5.0 mapping software and the interval mapping method were used to perform QTL mapping analysis on the flavonoid content in hawthorn leaves in these three periods.The studied population were the 107 F1generation hybrid population of’Shandongdamianqiu’×’Qiujinxing’and the 130 F1generation hybrid population of’Shandongdamianqiu’×’Xinbinruanzi’,respectively.The main results are as follows:1.The dynamic change data of flavonoid content were provided by the research group,and the period was from June 1,2015 to October 9,2015,samples were collected every 10days for a total of 15 periods.The flavonoid content of hawthorn leaves in these 15 periods was determined and analyzed,the results showed that the total flavonoid content of hawthorn leaves in the growth season of change range between 0.2482%and 1.100%.Among the five flavonoid monomers,the content of vitexin rhamnoside is the highest,and the content varies between 0.2294%and 1.0214%.There are two peak periods of the hawthorn leaves flavonoids content in the growing season,on July 11 and August 20,respectively.Among them,the total flavonoid content was the highest on July 11.2.Under the condition of LOD≧3,in the F1population of’Shandongdamianqiu’×’Qiujinxing’in 2018,a total of 10 related QTL loci were obtained.These QTL loci were distributed in five linkage group,the phenotypic contribution rates ranged from 37.3%to 84%;In the F1population of’Shandongdamianqiu’×’Qiujinxing’in 2019,a total of 29 related QTL loci were obtained,and these QTL loci were distributed in fifteen linkage groups,the phenotypic contribution rates ranged from 21.1%to 92.9%;In the F1population of’Shandongdamianqiu’×’Xinbinruanzi’in 2019,a total of 10 related QTL loci were obtained,these QTL loci were distributed in five linkage groups,and the phenotypic contribution rates were 12.6%-58%.3.Among all the detected loci,six QTL were detected repeatedly in two periods.Among them,in the F1population of’Shandongdamianqiu’×’Qiujinxing’in 2019,JSTG8-1 was detected during the period of August 20th for two consecutive years;SLTG8-2,JSTG8-3 and JSTG9-1 were all located at 89.97c M in the linkage group LG6,it was isolated from the marker site m2172,SLTG7-1 and SLTG9-2 is located at 22.72c M in linkage LG13group,co-segregated with marker site m516,SLTG8-3,SLTG9-1 were located at 24.51c M in linkage group LG11,it was co-segregated with the marker f551,SLTG7-2 and MJS8-1 were both located at at the position of 36.76c M in the linkage group LG14,and co-segregated with the marker f1518,JSTG8-7 and MJS9-1 were both located at the position of 55.78c M in the linkage group LG15,and co-segregated with the marker site dm918,both MJS7-2 and JSTG7-1were located at 59.36c M in linkage group LG12,were co-segregated with the marker site m2062;In the F1population of’Shandongdamianqiu’×’Xinbinruanzi’in 2019,no repeated QTL was detected. |
