Zwierzykowski Zbigniew, Kosmala Arkadiusz, Zwierzykowska Elzbieta, Jones Neil, Jokś Wojciech, Bocianowski Jan
Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479, Poznan, Poland.
Theor Appl Genet. 2006 Aug;113(3):539-47. doi: 10.1007/s00122-006-0322-2. Epub 2006 Jun 14.
In the allotetraploid, Festuca pratensis Huds. (2n = 4x = 28) x Lolium perenne L. (2n = 4x = 28) the balance of chromatin, as determined by GISH, changes over successive generations of open pollination in favour of L. perenne. There is extensive recombination between chromosomes of the two parental genomes, as well as substitution of whole Festuca chromosomes by whole Lolium chromosomes. The total number of Lolium chromosomes increased from a mean 14.36 in the F(2) to 16.26 in the F(6), and the total number of Festuca chromosomes decreased correspondingly from a mean of 13.57 to a value of 11.56. The number of recombinant chromosomes and recombination breakpoints per genotype also increased from generation to generation, although the respective values of both characters were higher for Festuca (0.86-8.41 and 1.14-15.22) than for Lolium (0.68-4.59 and 0.68-6.0). The proportion of total genome length contributed by the L. perenne chromatin increased from about 50% in F(2) to 59.5% in F(6). The results are based on the sample of 134 plants studied (26-28 plants per generation), and are discussed in terms of the dominance of Lolium chromosomes over those of Festuca, and possible mechanisms underlying this phenomenon of chromatin substitution.
在异源四倍体草地羊茅（Festuca pratensis Huds.，2n = 4x = 28）×多年生黑麦草（Lolium perenne L.，2n = 4x = 28）中，通过基因组原位杂交（GISH）确定，染色质平衡在连续几代的开放授粉过程中发生变化，有利于多年生黑麦草。两个亲本基因组的染色体之间存在广泛重组，同时还存在整个黑麦草染色体对整个羊茅染色体的替代。黑麦草染色体的总数从F(2)代的平均14.36条增加到F(6)代的16.26条，而羊茅染色体的总数相应地从平均13.57条减少到11.56条。每个基因型的重组染色体数量和重组断点数量也逐代增加，尽管这两个特征的各自值对于羊茅（0.86 - 8.41和1.14 - 15.22）高于多年生黑麦草（0.68 - 4.59和0.68 - 6.0）。多年生黑麦草染色质贡献的基因组总长度比例从F(2)代的约50%增加到F(6)代的59.5%。结果基于对134株植物的样本研究（每代26 - 28株植物），并从黑麦草染色体相对于羊茅染色体的优势以及这种染色质替代现象背后的可能机制方面进行了讨论。
