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用普通小麦与硬粒小麦 -簇毛麦双二倍体杂交 ,对其杂种F1的花粉母细胞中期Ⅰ的染色体配对进行了洋红染色和Giemsa -C带染色观察。结果表明虽然簇毛麦染色体在中期Ⅰ主要以单价体存在 ,但也有少量的小麦 -簇毛染色体配对 (平均每细胞为 1 1%左右 ) ,可以通过遗传重组转移簇毛麦的有利基因。这些小麦 -簇毛麦染色体配对 ,既分布在超过理论配对数的细胞中 ,也存在于少于理论配对数的细胞中 ;相反 ,超过理论配对数的染色体对不一定就是小麦 -簇毛麦染色体之间的配对 ,在少于理论配对数的细胞中 ,也不一定仅是小麦同源染色体的配对 ,同样包含有少量的小麦 -簇毛麦染色体配对。因而 ,用传统的染色法对外源物种与小麦染色体之间的配对数的估计 ,既有夸大一部分信息 ,又有掩盖一些有益信息的弊端。说明我们在用传统方法来推测远缘杂种后代中部分同源染色体配对时要持审慎的态度 ,需要用较为准确的方法来直接鉴定
The diploid chromosomes of metaphase Ⅰ of pollen mother cells from hybrid F1 were observed by Gd-C-band staining with the diploid hybrid of Durum and Triticum dicv. The results showed that although chromosomes of H. amurense were present mainly as monovalent species in metaphase I, there were also a few wheat-cluster chromosome pairs (average about 1 1% per cell), which could be transferred by genetic recombination. These wheat-cluster-maize chromosome pairing is not only distributed in cells that exceed the theoretical pairing number but also in cells that are less than the theoretical pairing number; rather, the chromosome pair that exceeds the theoretical pairing number is not necessarily the wheat-cluster-maize chromosome The pairings, in less than the theoretical number of paired cells, are not necessarily paired with wheat homologous chromosomes, but also contain small amounts of wheat-cluster maize chromosome pairs. Thus, the estimation of the number of paired exogenous species and wheat chromosomes using traditional staining methods not only exaggerates some of the information, but also masks the disadvantages of some useful information. This suggests that we should adopt a more cautious approach when using traditional methods to infer partial pairing of homologous chromosomes among distant hybrid progeny.