Genetic mapping of the pear scab resistance gene Vnk of Japanese pear cultivar Kinchaku
Genetic mapping of the pear scab resistance gene Vnk of Japanese pear cultivar Kinchaku
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DOI：
10.1007/s00122-006-0344-9
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发表时间：
2006-08-01
影响因子：
5.4
通讯作者：
Yamamoto, T.
中科院分区：
文献类型：
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作者：
Terakami, S.;Shoda, M.;Yamamoto, T.
梨黑星病（Venturia nashicola）是梨的主要病害之一，对日本梨和中国梨危害最大。抗病植株的分子鉴定和早期选择将大大提高梨的育种水平。我们已经确定了赤霉病抗性基因的位置，指定Vnk在日本本土梨品种Kinchaku，梨基因组内使用简单重复序列（SSR）标记来自梨和苹果。Vnk基因定位于Kinchaku第1连锁群的中心区域。通过群体分离分析，获得了与Vnk连锁的AFLP标记。其中，最接近Vnk的AFLP标记被转换成序列标记位点（STS）标记。四个随机扩增多态性DNA（RAPD）标记，以前发现与Vnk松散相关（Iketani等，2001年）被成功地转换成STS标记。6个标记（1个SSR Hi 02 c 07和5个AFLP和RAPD标记转化的STS）与Vnk紧密连锁，定位距离为2.4 ~ 12.4cM。从含有苹果黑星病基因Vf的重叠群的BAC克隆中分离的SSR标记CH-Vf 2定位在Kinchaku的第1连锁群的底部，表明Vnk和Vf位点位于同一同源连锁群的不同基因组区域。
Pear scab (caused by Venturia nashicola) is one of the most harmful diseases of pears, especially Japanese and Chinese pear species. The molecular identification and early selection of resistant plants could greatly improve pear breeding. We have identified the position of the scab resistance gene, designated Vnk in an indigenous Japanese pear cultivar Kinchaku, within the pear genome by using simple sequence repeat (SSR) markers derived from pear and apple. The position of Vnk was identified in the central region of linkage group 1 of Kinchaku. Several amplified fragment length polymorphism (AFLP) markers linked to Vnk were obtained by bulked segregant analysis. Among them, the AFLP marker closest to Vnk was converted into a sequence tagged site (STS) marker. Four random amplified polymorphic DNA (RAPD) markers previously found to be loosely associated with Vnk (Iketani et al. 2001) were successfully converted into STS markers. Six markers (one SSR Hi02c07 and five STSs converted from AFLP and RAPD) showed tight linkages to Vnk, being mapped with distances ranging from 2.4 to 12.4 cM. The SSR CH-Vf2, which was isolated from a BAC clone of the contig containing the apple scab gene Vf, was mapped at the bottom of linkage group 1 in Kinchaku, suggesting that the Vnk and Vf loci are located in different genomic regions of the same homologous linkage group.