3个抗条锈病小偃麦附加系中偃麦草染色体同源性鉴定

Identification of Two Pairs of Agropyron intermedium Chromosomes with Resistance to Puccinia striiformis in Different Wheat Alien Addition Lines

已经建立了3个抗条锈病小偃麦二体附加系,分别编号为 A1,A2和 A3。它们衍生于铭贤169与中4的杂交后代。铭贤169是一个普通小麦品种,它对我国现有全部条锈菌小种均高度感染。中4是人工合成的异源八倍体新种,含有全套小麦染色体和7对中间偃麦草染色体,对目前我国所有条锈菌小种均免疫或高抗。将铭贤169与中4杂交、用铭贤169回交、回交后代自交及抗病性鉴定得到了 A1,A2和 A3。为了搞清这3个附加系所附加染色的异同,将A1,A2和A3两两杂交,检查其 F_1植株减数分裂过程中染色体配对情况。在 A1×A2和 A2×A3的 F_1小孢子母细胞中出现了两个单价体染色体,在 A1×A3的 F_1中未发现单价体。这表明,A1与 A3所附加的是同一对中间偃麦草染色体,A2所附加的则是另一对。结论是,已经从中4鉴定出两种抗条锈病的中间偃麦草染色体,这两对染色体之间不具有同源性。

A1,A2 and A3,the three addition lines of Triticum aestivum-Agropyron intermedium with 21 pairs of wheat chromosomes and one pair of Ag.intermedium chromosomes,which had been estab- lished in our previous studies and proved to be resistant to Puccinia striiformis,were crossed each other. Meiosis of F1 plants of the crosses was observed.In the F_1 plants of A1×A2 and A2×A3,microsporo- cytes had two monovalent chromosomes,while in microsporocytes of F1 plants of A1×A3,there was no monovalent chromosomes.The observations suggested that the alien chromosomes in A1 and A3 were homologousand different(heterogenetic)from that in A2.It could be concluded that two separate pairs of Ag.intermedium chromosomes had been identified and added to common wheat,both of which were re- sistant to the P.striiformis races involved.