QTL Analysis Of Total Chlorophyll Content Of Melon Stigma

Melon?Cucumis melo L.?is an important fruit-type vegetable.In recent years,with the improvement of people's living standards,the demand for melons has gradually increased.How to increase the yield of melon has also become a key concern for melon production in China.The stigma is the site of the pollination process and the recipient of pollen.During pollination,insects do this by recognizing the color of flower organs.In the process of melon pollination and seed production and fruit production,the color of the green stigma and yellow pollen are greatly different,and it can be easily discerned whether the stigma is pollinated and the uniformity of pollination.Therefore,research on genes related to the control of stigma color of melon will help increase melon yield and provide data support for melon breeding.At the same time,with the development of sequencing technology,some genes can be quickly located,which greatly shortens the research time.In this study,green stigma melon“MR-1”and yellow stigma melon“M1-32”were used as parent materials to cross for F₁of hybridization and selfed for F₂ progeny and their genomes were re-sequenced.Using the BSA?Bulked Segregant Analysis?,the candidate intervals for controlling the color genes of melon stigma were initially selected.Based on the high-throughput sequencing results of the parents,SNP-CAPS primers were designed and developed using candidate bioinformatics within the candidate interval.A genetic linkage map was initially constructed using F₂ representative data combined with polymorphic markers for QTL analysis of total chlorophyll content in melon stigma.Then,encryption is performed in the positioning interval to obtain linkage markers with related traits.Finally,the candidate genes are predicted.The results of the main research are as follows:?1?The total chlorophyll content of melon stigma is a quantitative trait controlled by multiple genes.The total chlorophyll content of melon stigma is positively correlated with the stigma color.The darker the stigma color,the higher the chlorophyll content.?2?A genetic linkage map covering a genome length of 606.75 c M and an average distance between markers of 9.19 c M was constructed.The map includes 65 pairs of SNP-CAPS markers and 4 linkage groups.?3?Through the BSA combined with SNP-CAPS markers,two major QTLs?SC6.1 and SC8.1?of total chlorophyll content of melon stigma were detected on chromosomes 6 and 8 respectively,with contribution rates of 15.01%and 27.04%,respectively.Three candidate genes were selected in the SC8.1 candidate interval,which were related to zinc finger protein,chloroplast aldosterone reductase synthesis and chloroplast degradation.