PROMOTION OF HOMOEOLOGOUS CHROMOSOME-PAIRING IN HYBRIDS OF TRITICUM-AESTIVUM X AEGILOPS-VARIABILIS
PROMOTION OF HOMOEOLOGOUS CHROMOSOME-PAIRING IN HYBRIDS OF TRITICUM-AESTIVUM X AEGILOPS-VARIABILIS
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作者：
FAROOQ, S;IQBAL, N;SHAH, TM
以普通小麦品种鲁26和中国春ph 1 B突变体为材料，与易变山羊草A、B和E进行属间杂交。在减数分裂中期Ⅰ，同源异源染色体配对数量存在显著差异。以小麦品种鲁26为母本，以Ae. variabilis表现出非常少的配对，如每个细胞的交叉频率分别为1.0和1.5所示。另一方面，Lu-26和登录E之间的杂交表现出显著增加的同源配对（平均交叉频率，12.6/细胞）。这种配对水平与ph 1b ד中国春”的杂种基本相同。AE. variabilis种质A和B。然而，当ph 1b突变体与登录E杂交时，染色体配对水平显著增加（平均交叉频率，17.52/细胞）。这表明Ae中存在配对启动子基因。variabilis登录号E，其对小麦Ph 1等位基因是上位性的，并且与其突变体形式正相互作用以进一步增加小麦中ph 1b对同源配对的上限。
Intergeneric hybrids of Triticum aestivum variety Lu-26 and ph1b mutant of the cultivar Chinese Spring were produced with three accessions, A, B, and E, of Aegilops variabilis. Significant differences were found in the amount of homoeologous chromosome pairing at meiotic metaphase I. Hybrids between wheat variety Lu-26 and accessions A and B of Ae. variabilis showed very little pairing, as indicated by the chiasma frequency of 1.0 and 1.5 per cell, respectively. Hybrids between Lu-26 and accession E, on the other hand, showed significantly increased homoeologous pairing (mean chiasma frequency, 12.6/cell). The level of such pairing was essentially the same as that between the hybrids of ph1b ''Chinese Spring'' .times. Ae. variabilis accessions A and B. However, when the ph1b mutant was hybridized with accession E, the level of chromosome pairing increased significantly (mean chiasma frequency, 17.52/cell). This is indicative of the presence of pairing promoter gene(s) in Ae. variabilis accession E, which are epistatic to the wheat Ph1 allele and positively interact with its mutant form to further increase the ph1b ceiling to homoeologous pairing in wheat.