Ecke Wolfgang, Kampouridis Anthimos, Ziese-Kubon Katharina, Hirsch Ann-Catrin
Department of Crop Sciences, Georg-August-Universität Göttingen, Von-Siebold-Str. 8, 37075, Göttingen, Germany,
Theor Appl Genet. 2015 Apr;128(4):587-603. doi: 10.1007/s00122-015-2455-7. Epub 2015 Jan 28.
Seven intervarietal substitution lines were identified with embryogenic potentials up to 40.4 times that of the recurrent parent, providing an ideal material for further in depth studies of this trait. To identify genomic regions that carry genetic factors controlling embryogenic potential of isolated microspores of rapeseed, marker segregations were analysed in a segregating population of haploid microspore-derived embryos and a BC1 population from a cross between 'Express 617' and 'RS239'. After map construction 15 intervarietal substitution lines from the same cross with 'Express 617' as recurrent parent were selected with donor segments covering five genomic regions that had shown skewed segregations in the population of microspore-derived embryos but not in the BC1 population. By comparing the embryogenic potential of microspores of the 15 substitution lines and 'Express 617', seven lines were identified with significantly enhanced embryogenic potential ranging from 4.1 to 40.4 times that of 'Express 617'. To improve the genetic characterization of the selected lines, they were subjected to a high-throughput SNP analysis using the Illumina Infinium 60K chip for rapeseed. Based on 7,960 mapped SNP markers, one to eight donor segments per line, which cover 0.64-6.79% of the 2,126.1 cM of the SNP map, were found. The SNP analysis also gave evidence that homoeologous exchanges had occurred during the development of the substitution line population, increasing the genetic diversity within this population. By comparing donor segments between lines with significantly enhanced embryogenic potential and non-significant lines, 12 genomic regions were identified that may contain genetic factors controlling embryogenic potential in rapeseed. These regions range in size from 0 (represented by just one marker) to 26.8 cM and cover together just 5.42% of the SNP map.
鉴定出7个品种间置换系，其胚发生潜能比轮回亲本高40.4倍，为该性状的进一步深入研究提供了理想材料。为了鉴定携带控制油菜小孢子胚发生潜能遗传因子的基因组区域，在单倍体小孢子衍生胚的分离群体以及‘Express 617’与‘RS239’杂交的BC1群体中分析了标记分离情况。构建图谱后，从与‘Express 617’为轮回亲本的同一杂交组合中选择了15个品种间置换系，其供体片段覆盖了5个基因组区域，这些区域在小孢子衍生胚群体中表现出偏分离，但在BC1群体中未表现出偏分离。通过比较15个置换系和‘Express 617’小孢子的胚发生潜能，鉴定出7个胚发生潜能显著增强的品系，其胚发生潜能是‘Express 617’的4.1至40.4倍。为了改进所选品系的遗传特征描述，使用油菜Illumina Infinium 60K芯片对它们进行了高通量SNP分析。基于7960个定位的SNP标记，发现每个品系有1至8个供体片段，覆盖SNP图谱2126.1 cM的0.64 - 6.79%。SNP分析还表明，在置换系群体发育过程中发生了同源交换，增加了该群体内的遗传多样性。通过比较胚发生潜能显著增强的品系和非显著增强品系之间的供体片段，鉴定出12个可能包含控制油菜胚发生潜能遗传因子的基因组区域。这些区域大小从0（仅由一个标记代表）到26.8 cM不等，总共仅覆盖SNP图谱的5.42%。
