中文摘要：

易位系是指一个物种的染色体与另一物种染色体发生单向或相互易位的个体,易位系中外源染色体片段的遗传稳定性研究对外源优良基因的利用具有重要意义。为创建大白菜（Brassica compestris ssp.pekinensis,AA）-结球甘蓝（Brassica oleracea var.capitata,CC）易位系,本研究以大白菜-结球甘蓝7号单体异附加系（AC7）、二倍体大白菜亲本85-1和结球甘蓝11-1为实验材料,采用45 Gy60Co-γ射线对其花粉进行辐射,用辐射后的花粉与二倍体大白菜亲本回交获得M1植株,并对M1植株进行自交获得M2。利用结球甘蓝7号染色体相对应的结球甘蓝01连锁群特异（相对于大白菜）的31个In Del（Insertion-Deletion）标记对M2进行筛选,结合细胞学鉴定从M2中获得了10个易位系植株,从中选择了两个添加不同甘蓝片段的易位系植株AT7-1和AT7-2进行游离小孢子培养和自交、回交留种,利用结球甘蓝特异的In Del标记对AT7-1和AT7-2的自交、回交后代和小孢子植株进行鉴定,并对其自交后代的田间农艺性状进行了调查。结果表明,两个易位系中外源染色体片段的遗传稳定性不同,同一易位系自交、回交后代和小孢子植株中外源染色体片段的稳定性亦有差异。AT7-1的自交、回交后代和小孢子植株中具有甘蓝片段的植株比例分别为73%、28%和50%;AT7-2的自交、回交后代和小孢子植株中具有甘蓝片段的植株比例别为84%、62%和25%。AT7-1自交后代植株的结球性状出现分离,而AT7-2自交后代植株的结球性状没有明显分离。大白菜背景中外源染色体的遗传稳定性研究结果为大白菜新种质在育种中的应用提供了参考资料。

英文摘要：

Translocation line is an individual formed by one-way or reciprocal translocation between chromosomes of two different species.It is significantly important for the application of excellent exogenous gene to study the genetic stability of exogenous chromosome in translocation lines.In order to obtain Chinese cabbage（Brassica oleracea var.capitata）-cabbage（Brassica compestris ssp.pekinensis） translocation lines,Chinese cabbage-cabbage alien addition line 7#（AC7） and its parents Chinese cabbage 85-1 and cabbage 11-1were used as experimental population in present study.Using rays 45 Gy60Co-γ radiating pollens of AC7,M1 plants were obtained by backcrossing irradiated pollens with Chinese cabbage 85-1,and then M2 plants were obtained by selfing M1.Using 31 specific In Del（Insertion-Deletion） markers（compared with Chinese cabbage）distributed in linkage group No.1 of cabbage,and combining with cytological observation,ten translocation lines were identified from selfing progenies of M2 plants.Two translocation lines AT7-1 and AT7-2 with different chromosome fragments of cabbage were selected and studied,for which isolated microspore culture,selfing and backcrossing were further performed.Using specific In Del markers,progeny plants from selfing,backcrossing and microspore culture of two translocation lines were identified.We also had carried on investigation of phenotypic traits in selfing progenies of AT7-1 and AT7-2.The results showed that genetic stability of two translocation lines AT7-1 and AT7-2 with different chromosome fragments of cabbage was different.The genetic stability of selfing progenies,backcross progenies and microspore culture plants in the same translocation line was also different.In AT7-1,the ratio of keeping exogenous fragment in selfing progenies,backcross progenies and microspore culture plants was 73%,28% and 50%,respectively.In AT7-2,the ratio of keeping exogenous fragment in selfing progenies,backcross progenies and microspore culture plants was 84%,62% and 25%,respectivel