凌云牛心李DNA条形码筛选及其亲缘关系分析

本研究通过对9份凌云牛心李进行ITS、matK及rbcL序列PCR扩增和序列比对分析，旨在筛选适合于凌云牛心李开展遗传多样性研究的DNA条形码。通过序列比对分析，9份李种质ITS序列长度在713 bp~717 bp之间，G+C含量59.33%~60.95%之间，存在27个变异位点；matK序列长度为935 bp~937 bp之间，G+C含量33.33%~33.55%之间，存在5个变异位点；rbcL序列长度为743 bp，G+C含量42.20%~43.07%，存在3个变异位点。相对于matK及rbcL序列，ITS序列进化速率较快，存在更为丰富的遗传变异位点，更适宜用来开展凌云牛心李的分子鉴定及亲缘关系分析研究。基于ITS序列构建了9份凌云牛心李、22份其他地区李种质以及5份杏、5份梅种质的NJ系统进化树，凌云牛心李与其他李种质亲缘关系较近，其中N2、N3、N8和N9中国宁波的茄皮李和日本的大石早生李聚为一个类群，而N1、N4、N5、N6和N7与中国嘉兴的槜李、中国山东的玉皇李、中国贵州的九阡李聚为一个分支，表明凌云牛心李作为地方优质李品种，在长期种植过程中种内产生了较丰富的遗传变异。

DNA Barcode Screening and Genetic Analysis of Lingyun Niuxin Plum

In this study, PCR amplification and sequence alignment of ITS, matK and rbcL sequences were performed on 9 Lingyun Niuxin plum, aiming at screening DNA barcodes suitable for genetic diversity research of Lingyun Niuxin plum. Through sequence alignment analysis, the ITS sequence length of 9 Lingyun Niuxin plums ranged from 713 bp to 717 bp, the content of G+C ranged from 59.33% to 60.95%, and there were 27 variation locus. The length of matK sequence was between 935 bp and 937 bp, the content of G+C was between 33.33% and 33.55%, and there were five mutation sites. The length of rbcL sequence was 743 bp, the content of G+C was 42.20%-43.07%, and there were three mutation sites. Compared with matK and rbcL, ITS sequence had a faster evolutionary rate and more abundant genetic variation loci, which was more suitable for molecular identification and phylogenetic analysis of Lingyun Niuxin Plum. Based on ITS sequence, an NJ phylogenetic tree was constructed for 9 germplasms of Lingyun Niuxin plum, 22 germplasms of other plums, 5 germplasms of apricus and 5 germplasms of plums. The phylogenetic tree of Lingyun Niuxin plum were closely related to other germplasms of plum, in which N2, N3, N8 and N9 are clustered into a single group of Jiapi plum from Ningbo, China and Daishishao Plum from Japan. N1, N4, N5, N6 and N7 are clustered into a branch with ZuiLi plum from Jiaxing, China, Yuhuang plum from Shandong, China, and Jiuqian plum from Guizhou, China, indicating that Lingyun Niuxin plum, as a local high-quality plum variety, has produced relatively rich genetic variation within the species during long-term planting.