B染色体组对芸苔属部分同源染色体组A．B．C之间染色体配对关系的影响

THE EFFECT OF B GENOME ON THE CHROMOSOSME PAIRING RELATIONSHIP BETWEEN THE THREE HOMOLOGOUS GENOMES A B AND C IN BRASSICA

观察了芸苔属４个种（黑芥、甘蓝型油菜、芥菜型油菜和埃塞俄比亚芥）间杂种Ｆ＿１花粉母细胞减数分裂中期Ｉ染色体的配对行为，结果表明，芥菜型油菜×黑芥、埃塞俄比亚芥×黑芥、芥菜型油菜×埃塞俄比亚芥、芥菜型油菜×甘蓝型油菜和甘蓝型油菜×埃塞俄比亚芥Ｆ１杂种分别平均表现出９．７７Ｉ＋８．０３Ⅱ＋０．０３Ⅲ、８．８２Ｉ＋８．０２Ⅱ＋０．０５２Ⅲ，２．５６Ｉ＋１４．９８Ⅱ＋０．３９Ⅲ＋０．３３Ⅳ（Ⅴ），１４．１７Ｉ＋１１．１５Ⅱ＋０．１３３Ⅲ＋０．０２７Ⅳ和１５．４２Ｉ＋１０．１４Ⅱ＋０．０８５Ⅲ＋０．０１４Ⅳ的构型。由此说明，在芸苔属Ａ、Ｂ和Ｃ染色体组之间，Ａ与Ｃ的同源性大于Ａ与Ｂ或Ｂ与Ｃ的同源性；同时，Ｂ染色体组对Ａ与Ｂ、Ａ与Ｃ及Ｂ与Ｃ之间的部分同源染色体配对关系没有影响。

The study investigated the pollen-mother-cell's meiotic chromosome pairing behavior of the five interspecific hybrids resulting from the hybridizaion between four Brassica species,i.e.,B. nigra,B.napus,B. juncea and B. carinata. It was found that the F1 hybrids of B.juncea×B.nigra,B.Carinata×B. nigra,B juncea×B, carinata,B. juncea×B. napus and B.carinata×B. napus showed a mean meiotic chromosome formulation of 9. 77 I+8. 03 Ⅱ+0.03Ⅲ,8. 82 I+8.02Ⅱ+0.052 Ⅲ,2.56 I+14. 98 Ⅱ+0. 39Ⅲ+0.33Ⅳ(Ⅴ),14. 17 I+11.15 Ⅱ+0.133Ⅲ+0.027 Ⅳ and 15. 42 I+10.14Ⅱ+0. 085Ⅲ+0. 014Ⅳ, respectively.These results suggested that the degree of chromosome relationship between A and C genome is higher than that be tween A and B or B and C;and also the B genome had no genetic suppression on the ho mologous chromosome pairing between A.Band C.