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鸭茅是重要的冷季型禾本科牧草,而优质分子标记的缺乏制约了鸭茅分子育种的进程。本研究从鸭茅基因组序列中鉴定出78 984个SSR位点,其中单核苷酸、二核苷酸和三核苷酸的SSR类型共占98.1%。共鉴定出212种重复基元,A/T、AG/CT、CCG/CGG、AGAT/ATCT、AAAAG/CTTTT和AGAGAT/ATCTCT分别为各重复类型中最丰富的重复基元。通过鉴定出的SSR位点开发出67 216对Genomic-SSR引物,选取50对进行验证试验,其扩增成功率达94%,多态性比例44%。通过开发的Genomic-SSR引物和EST-SSR引物在20个鸭茅品种(系)中进行试验,得到其引物多态性信息含量(PIC)平均值为0.370,分子标记指数(MI)为2.86。以上数据均高于通过鸭茅转录组开发的EST-SSR标记。证明本试验所开发的大量genomic-SSR标记是扩增成功率高、多态性强且高效率的分子标记,有望在鸭茅分子育种中发挥重要作用。
Dactylis glomerata is an important cold-season gramineous grass, and the lack of high-quality molecular markers restricts the breeding process of Dactylis glomerata. In this study, 78 984 SSR loci were identified from the genome sequence of Dactylis glomerata, in which the single nucleotide, dinucleotide and trinucleotide SSR types accounted for 98.1%. A total of 212 kinds of repeat motifs were identified. A / T, AG / CT, CCG / CGG, AGAT / ATCT, AAAAG / CTTTT and AGAGAT / ATCTCT were the most abundant repeat motifs in each repeat type. A total of 67 216 pairs of Genomic SSR primers were developed from the identified SSR loci. Fifty pairs of primers were selected for validation. The success rate of amplification was 94% and the percentage of polymorphisms was 44%. The genomic SSR primers and EST-SSR primers were used to test the genetic diversity of 20 species of Dactylis glomerata (L.). The average value of polymorphic information content (PIC) was 0.370 and the molecular marker index (MI) was 2.86. The above data are higher than the EST-SSR marker developed by the Drosophila melanogaster transcriptome. It is proved that a large number of genomic-SSR markers developed in this study are molecular markers with high success rate, strong polymorphism and high efficiency and are expected to play an important role in molecular breeding of Dactylis glomerata.