硬粒小麦-簇毛麦双二倍体与普通小麦杂种F1的花粉母细胞减数分裂行为的研究

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

Chromosome Pairing Analysis in the PMCs of F1 Hybrids between Triticum Durum Dasypyrum Villosum Amphiploid and Common Wheats

The Meiotic behavior of T.durum D.villosum amphiploid with three bread wheat varieties (lines) was employed by acetocarmine and C-banding staining of PMCs at first metaphase to reveal homoeologous pairing between wheat and D.villosum chromosomes. The results indicated that the chromosome pairings more than expected in hybrid cell were homoeologous pairings either of wheat D.villosum chromosomes or of wheat wheat chromosomes. On the other hand, the pairings less than expected in a hybrid cell should be considered as homologous pairings of A-A or B-B chromosomes according to traditional Feulgen stained method, in fact, a few bivalents between wheat and D.villosum chromosomes in those cell with bivalents less than 14 were also observed, which reflected that estimation of homoeologous pairing between wheat and alien species genome chromosomes by standard Feulgen staining technique in AABBDV hybrid was non accurate. The difficulties to obtain wheat lines which carried desirable genes from D.villosum through homoeologous pairing and recombination were also discussed.