Origin of T-type chloroplast DNA in potato

普通马铃薯的叶绿体DNA与其直系祖先安第斯四元体栽培马铃薯不同，存在241个碱基的缺失，命名为T型叶绿体DNA。为了探索将T型叶绿体DNA赋予栽培马铃薯的祖先野生种，对来自玻利维亚和阿根廷的35个野生种的566份材料进行了简单的基于PCR的缺失检测。在S、贝特豪尔蒂、新红星和泰山红星等16份种质中均发现该缺失。对缺失区域的测序分析证实，241个碱基的缺失发生在同一区域。除了缺失的存在或不存在外，还利用两个PCR-RFLP标记(H2和H3)和四个微卫星标记(NTCP6、NTCP7、NTCP1.4和NTCP18)对伯氏链霉菌(30份)、新红链霉菌(5份)、塔氏链霉菌(62份)、推测的伯氏链霉菌(25份)、结瘤链霉菌(SSP)进行了鉴定。Tubetosum(7份材料，主要来自智利)和SSP.Andigena(5份材料，均具有T型叶绿体DNA)，以及狭窄链霉菌、金鱼藻和链霉菌各1个。共鉴定出25种单倍型。所有含有T型叶绿体DNA的马铃薯种质均为单倍型1持有者。在14份塔氏链霉菌和4份塔里氏链霉菌种质中也发现了触角型1。这有力地表明，普通马铃薯的野生母系祖先是甘肃甘薯。

Chioroplast DNA of the common potato is different from that of its immediate ancestor, the Andean tetrapiold cultivated potato, by the presence of a 241 bp deletion and named T-type chioroplast DNA. To explore the ancestral wild species that conferred T-type chioroplast DNA to the cultivated potatoes, 566 accessions of 35 wild species from Bolivia and Argentina were surveyed for the presence/absence of the deletion by a simple PCR-based assay. The deletion was found in 16 accessions of S, berthaulti, S.neorossli and S.tarijense. The sequencing analysis of the deleted region confirmed that the 241 bp deletion occurred in the same region. In addition to the presence/absence of the deletion, two PCR-RFLP markers (H2 and H3) and four microsatellite markers (NTCP6, NTCP7, NTCP1.4 and NTCP18) were used to evaluate S. berthaultii (30 accessions), S. neorossii (five accessions), S. tarijense (62 accessions), putative S. berthaultiix S. tarijense hybrids (25 accessions), S. tuberosum ssp. tubetosum (7 accessions mostly from Chile) and ssp. andigena (five accessions, all having T-type chioroplast DNA), and one accession from each of S. stenotomum, S. phureja and S. chacoense. Twenty-five haplotypes were distinguished. All of the S. tuberosum accessions having T-type chtoroplast DNA were distinguished as haplotype 1 holders. The haptotype 1 was also found in 14 accessions of S. tarijense and four accessions of S. berthaultiix S. tarijense hybids. This strongly suggests that the wild maternal ancestor of common potato was S. tarijense.