Sato Maho, Shimizu Motoki, Shea Daniel J, Hoque Mozammel, Kawanabe Takahiro, Miyaji Naomi, Fujimoto Ryo, Fukai Eigo, Okazaki Keiichi
Laboratory of Plant breeding, Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Nishi-ku, Niigata 950-2181, Japan.
Kakegewa Research Center, Sakata Seed Corporation, 1743-2 Yoshioka, Kakegawa, Shizuoka 436-0115, Japan.
Breed Sci. 2019 Jun;69(2):308-315. doi: 10.1270/jsbbs.18156. Epub 2019 May 8.
The fusarium yellows resistance (YR) gene was previously identified and the DNA markers were developed to assist the breeding of YR cultivars in . However, the further analysis revealed discrepancies between the phenotypes and the genotypes predicted by those DNA markers in cabbage commercial cultivars. Since this discrepancy seemed to be due to unknown susceptible alleles of , we sequenced the gene in 19 accessions to determine the sequence variations between alleles and found that there were two resistant alleles and six susceptible alleles in the investigated population. The newly designed PCR markers detected three mutations in the susceptible alleles that generate premature termination codons. These were shown to accurately distinguish resistant and susceptible alleles in more than 200 accessions of inbred lines and cultivars. The study revealed that the locus is represented by 37.2% resistant and 62.8% susceptible alleles within seventy-eight commercial cultivars. Structural analysis of the gene revealed that a part of the allelic variation comes from intragenic recombination between alleles. Our results enable a more precise prediction of the phenotype by marker assisted selection, promoting the production of YR cultivars in .
先前已鉴定出甘蓝枯萎病抗性（YR）基因，并开发了DNA标记以辅助甘蓝抗枯萎病品种的选育。然而，进一步分析发现，这些DNA标记预测的甘蓝商业品种的表型与基因型之间存在差异。由于这种差异似乎是由未知的感病等位基因导致的，我们对19份材料中的该基因进行了测序，以确定等位基因之间的序列变异，结果发现在所研究的群体中有两个抗性等位基因和六个感病等位基因。新设计的PCR标记检测到感病等位基因中的三个突变，这些突变产生了提前终止密码子。结果表明，这些标记能够准确区分200多个甘蓝自交系和品种中的抗性和感病等位基因。研究表明，在78个商业品种中，该位点的抗性等位基因占37.2%，感病等位基因占62.8%。对该基因的结构分析表明部分等位基因变异来自等位基因间的基因内重组。我们的研究结果能够通过标记辅助选择更精确地预测表型，从而推动甘蓝抗枯萎病品种的培育。
