栽培黑麦 B 染色体的起源。

Origin of B chromosomes in cultivated rye.

出版信息

Genome. 1995 Apr;38(2):307-12. doi: 10.1139/g95-038.

Abstract

Cultivated rye (Secale cereale) and its weedy relative (S. segetale) carry B chromosomes. The B chromosomes are known to be morphologically alike at somatic metaphase and they are of the standard type in natural populations. To clarify the cytogenetic relationship between the standard B chromosomes of S. cereale and those of S. segetale, we made four crosses between Afghan S. segetale with two standard B chromosomes as a pistillate parent and Turkish, Iranian, Korean, and Japanese S. cereale, all with two standard B chromosomes as pollen parents. We observed the pairing of B chromosomes at diakinesis in pollen mother cells in all F1 hybrids with four standard B chromosomes, two from each of the pistillate and the pollen parents. The degree of pairing of B chromosomes in all F1 hybrids with four standard B chromosomes was similar to or somewhat lower than, that in parental strains with four standard B chromosomes. These results showed that the standard B chromosomes in S. segetale from Afghanistan are homologous with those in S. cereale from Turkey, Iran, Korea, and Japan. We therefore propose monophyletic origin of the standard B chromosomes in S. segetale and S. cereale.

摘要

栽培黑麦（Secale cereale）及其野生近缘种（S. segetale）携带 B 染色体。已知 B 染色体在体细胞中期的形态相似，并且在自然种群中属于标准类型。为了澄清栽培黑麦的标准 B 染色体与 S. segetale 的 B 染色体之间的细胞遗传学关系，我们在阿富汗 S. segetale 与两个标准 B 染色体作为雌性亲本之间进行了四次杂交，而土耳其、伊朗、韩国和日本的 S. cereale 则都具有两个标准 B 染色体作为花粉亲本。我们观察了所有具有四个标准 B 染色体的 F1 杂种花粉母细胞中的 B 染色体在减数分裂前期的配对情况，每个雌性亲本和花粉亲本各有两个 B 染色体。所有具有四个标准 B 染色体的 F1 杂种中 B 染色体的配对程度与具有四个标准 B 染色体的亲本菌株相似或略低。这些结果表明，来自阿富汗的 S. segetale 的标准 B 染色体与来自土耳其、伊朗、韩国和日本的 S. cereale 的标准 B 染色体是同源的。因此，我们提出 S. segetale 和 S. cereale 的标准 B 染色体具有单系起源。