Introgression mapping in the grasses. II. Meiotic analysis of the Lolium perenne/Festuca pratensis triploid hybrid
Introgression mapping in the grasses. II. Meiotic analysis of the Lolium perenne/Festuca pratensis triploid hybrid
复制标题
草丛中的基因渗入作图。
作者：
I. King;W. Morgan;J. Harper;H. Thomas
多年生黑麦草/多年生黑麦草/草地羊茅三倍体杂种是确定农艺和科学上重要性状的遗传控制以及确定遗传图谱与物理图谱之间关系的潜在重要材料来源。L. perenne（Lp）和F. Pratensis（Fp）的基因型尚不清楚。为了确定Lp和Fp之间的基因组关系，使用基因组原位杂交（GISH）和Chapman和Kimber数学模型（1992）分析了LpLpFp三倍体杂种的性母细胞中的中期I。这两个分析清楚地表明，重组优先发生在同源Lp基因组之间的LpLpFp三倍体，表明这两个物种的基因组已经分化。通过GISH测量的同源与同源异源染色体关联的直接分析与数学分析广泛一致。因此，Chapman和Kimber模型（1992）是一个有效的方法来评估这些三倍体杂种的染色体配对。这些数据对阐明L. perenne和F. Pratensis进行了讨论。
Lolium perenne/Lolium perenne/Festuca pratensis triploid hybrids are a potentially important source of material for determining the genetic control of agronomically and scientifically important characters and determining how genetic maps relate to physical maps. The evolutionary relationship between L. perenne (Lp) and F. pratensis (Fp) is, however, unclear. In order to determine the genomic relationships between Lp and Fp, genomic in situ hybridization (GISH) and the Chapman and Kimber mathematical model (1992) were used to analyse metaphase I in meiocytes of an LpLpFp triploid hybrid. Both analyses clearly demonstrated that recombination occurs preferentially between the homologous Lp genomes in the LpLpFp triploid, indicating that the genomes of the two species have diverged. Direct analysis of homologous vs. homoeologous chromosome association, as measured by GISH, was in broad agreement with the mathematical analysis. It is therefore concluded that the Chapman and Kimber model (1992) is a valid means of assessing chromosome pairing in these triploid hybrids. The significance of the data for elucidating the closeness of the relationship of L. perenne and F. pratensis is discussed.