关键词: 番茄, 集团分离群体测序, 抗坏血酸, QTL, SlPPO

Abstract: The F2 genetic segregating population was constructed via using high ascorbic acid（AsA）tomato accession TS-226 and low ascorbic acid tomato accession TS-228 as parents. The high-ascorbic acid and low-ascorbic acid pools were constructed respectively. Through bulked segregant analysis sequencing analysis（BSA-seq），the main QTL related to ascorbic acid was found，and the candidate gene related to ascorbic acid was located in the 58.00–60.15 Mb region of tomato chromosome 8. Furthermore，the ∆SNP-index data were analyzed to determine the main candidate gene SlPPO（Polyphenol oxidase）that controls the ascorbic acid content of tomato fruit. Using TS-228 as the background plant，transgenic lines with SlPPO overexpression and silencing were obtained by Agrobacterium-mediated transformation. Compared with the wild type，the total ascorbic acid content in the red ripe fruits of the overexpression lines OE-3 and OE-18 decreased by 18.89% and 26.56%，respectively. The total ascorbic acid content in the red ripe fruits of the silenced lines Ri-9 and Ri-16 increased by 37.53% and 63.93% relative to wild type，respectively. Taken together，SlPPO is the key gene to control the ascorbic acid content of tomato red ripe fruit，and plays a negative role in regulating fruit ascorbic acid content.

Key words: tomato, BSA-seq, ascorbic acid, QTL, SlPPO