[关键词]
[摘要]
玉米的胚乳由一个精子和两个极核发育而成,其中含有两份拷贝的母本基因信息和一份拷贝的父本基因信息。本研究基于玉米胚乳中母本和父本DNA的2:1的剂量关系利用20个InDel分子标记在荧光毛细管电泳平台上对玉米进行了亲子鉴定并得到玉米杂交种三联体的指纹数据。本研究分别利用8个玉米杂交种单株的胚及胚乳DNA得到在11个杂和位点上每个基因型的峰面积并计算得出胚和胚乳各自的等位基因扩增比(左峰面积/右峰面积)。通过比较发现胚及胚乳之间的等位基因扩增比具有显著差异;在其中4个标记上(IDP054、IDP151、IDP161、IDP238),胚乳DNA等位基因扩增比较胚DNA低,胚乳的右峰面积较大,说明右峰代表基因型的DNA含量较高,判断该位点右峰代表的基因型为母本基因型;依此判断另外7个标记的左峰代表基因型为母本基因型,最终得到玉米杂交种三联体的指纹数据;并通过与杂交种双亲的指纹进行比对验证了判断结果的正确性。本研究提出的玉米亲子鉴定方法可在仅有杂交种的情况下判断亲本基因型,减小了对亲本种子的依赖程度,降低了鉴定的难度,为玉米亲子鉴定提供了更丰富的选择。
[Key word]
[Abstract]
The endosperm of maize develops from one sperm and two polar nuclei, which contain two copies of maternal and one copy of paternal genetic information. In this study, we used 20 InDel markers on a fluorescent capillary electrophoresis platform to identify the parentage of maize based on the 2:1 dosage relationship between maternal and paternal DNA in maize endosperm and obtained the fingerprint data of maize hybrid triplets. The peak areas of each genotype at 11 heterozygous loci were obtained using embryo and endosperm DNA from 8 maize hybrids and the amplification ratio (left peak area/right peak area) was calculated for each allele of embryo and endosperm. The allele amplification ratios between embryo and endosperm were significantly different, and on 4 of the markers (IDP054, IDP151, IDP161, IDP238), the endosperm DNA allele amplification ratio was lower than that of the embryo DNA, and the right peak area of the endosperm was larger, indicating that the DNA content of the genotype represented by the right peak was higher, and the genotype represented by the right peak at this locus was judged to be the maternal genotype; accordingly, the left peak of the other 7 markers was judged to be the maternal genotype, and the fingerprint data of the maize hybrids triplet were finally obtained; and the correctness of the judgment results was verified by comparing with the fingerprints of both parents of the hybrids. The maize parentage identification method proposed in this study can determine the parental genotypes in the case of hybrids only, which reduces the dependence on parental seeds, decreases the difficulty of identification, and provides a richer choice for maize parentage identification.
[中图分类号]
[基金项目]
国家十三五重点研发计划“玉米分子设计育种”(2016YFD0101803)