CHROMOSOME-PAIRING RELATIONSHIPS AMONG THE A-GENOME, B-GENOME, AND D-GENOME OF BREAD WHEAT
CHROMOSOME-PAIRING RELATIONSHIPS AMONG THE A-GENOME, B-GENOME, AND D-GENOME OF BREAD WHEAT
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DOI：
10.1007/bf00588597
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发表时间：
1991-01-01
影响因子：
5.4
通讯作者：
BENNETT, JH
中科院分区：
文献类型：
--
作者：
JAUHAR, PP;RIERALIZARAZU, O;BENNETT, JH
染色体配对和交叉频率进行了研究，在面包小麦真单倍体（2n = 3x = 21; ABD基因组）与和没有主要的配对调节Ph 1。 这构成了第一个报告的染色体配对关系之间的A，B和D基因组的小麦没有外来基因组的影响。 所有Ph 1整单倍体几乎没有配对，每个细胞有0.62-1.05个杆状二价体;环二价体几乎不存在，平均臂结合频率（c）值范围为0.050至0.086。 而ph 1b真单倍体具有广泛的同源配对，交叉频率是Ph 1真单倍体的7.5-11.6倍。 它们有0.53-1.16个三价体、1.53-1.74个环二价体和2.90-3.57个杆状二价体，c从0.580到0.629。 减数分裂染色体的N-显带显示出强烈的优先配对的A和D基因组的染色体之间，80%的配对是这些基因组之间，特别是在存在的ph 1b等位基因。 数学模型的应用，以未标记的染色体也支持2：1的基因组结构的ph 1b整单倍体。 数值模拟表明，约80%的中期I协会之间的两个最相关的基因组在ph 1b的存在下，但在Ph 1的配对是相当随机的。 数据表明，A和D基因组彼此之间的关系比它们与B之间的关系更密切。 这些结果可能具有系统发育的意义，因此育种的影响。
Chromosome pairing and chiasma frequency were studied in bread wheat euhaploids (2n = 3x = 21; ABD genomes) with and without the major pairing regulator Ph1. This constitutes the first report of chromosome pairing relationships among the A, B, and D genomes of wheat without the influence of an alien genome. All Ph1 euhaploids had very little pairing, with 0.62-1.05 rod bivalents per cell; ring bivalents were virtually absent and mean arm-binding frequency (c) values ranged from 0.050 to 0.086. In contrast, the ph1b euhaploids had extensive homoeologous pairing, with chiasma frequency 7.5-11.6 times higher than that in the Ph1 euhaploids. They had 0.53-1.16 trivalents, 1.53-1.74 ring bivalents, and 2.90-3.57 rod bivalents, with c from 0.580 to 0.629. N-banding of meiotic chromosomes showed strongly preferential pairing between chromosomes of the A and D genomes; 80% of the pairing was between these genomes, especially in the presence of the ph1b allele. The application of mathematical models to unmarked chromosomes also supported a 2:1 genomic structure of the ph1b euhaploids. Numerical modeling suggested that about 80% of the metaphase I association was between the two most related genomes in the presence of ph1b, but that pairing under Ph1 was considerably more random. The data demonstrate that the A and D genomes are much more closely related to each other than either is to B. These results may have phylogenetic significance and hence breeding implications.