Cao Yaping, Bie Tongde, Wang Xiue, Chen Peidu
National Key Laboratory of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University, Nanjing 210095, China.
J Genet Genomics. 2009 May;36(5):313-20. doi: 10.1016/S1673-8527(08)60120-4.
In order to develop more wheat-Haynaldia villosa translocations involving different chromosomes and chromosome segments of H. villosa, T. durum-H. villosa amphiploid was irradiated with 60Co gamma-rays at doses of 800, 1,200, and 1,600 rad. Pollen collected from the spikes 1, 2, and 3 days after irradiation were transferred to emasculated spikes of the common wheat cv. 'Chinese Spring'. Genomic in situ hybridization was used to identify wheat-H. villosa chromosome translocations in the M1 generation. Transmission of the identified translocation chromosomes was analyzed in the BC1, BC2, and BC3 generations. The results indicated that all three irradiation doses were highly efficient for inducing wheat-alien translocations without affecting the viability of the M1 seeds. Within the range of 800-1,600 rad, both the efficiency of translocation induction and the frequency of interstitial chromosome breakage-fusion increased as the irradiation dosage increased. A higher translocation induction frequency was observed using pollen collected from the spikes 1 day after irradiation over that of 2 or 3 days after irradiation. More than 70% of the translocations detected in the M1 generation were transmitted to the BC1 through the female gametes. All translocations recovered in the BC1 generation were recovered in the following BC2, and BC3 generations. The transmission ability of different translocation types in different genetic backgrounds showed an order of 'whole-arm translocation > small alien segment translocation > large alien segment translocation', through either male or female gametes. In general, the transmission ability through the female gametes was higher than that through the male gametes. By this approach, 14 translocation lines that involved different H. villosa chromosomes have been identified in the BC3 using EST-STS markers, and eight of them were homozygous.
为了培育出更多涉及绒毛草不同染色体和染色体片段的小麦-绒毛草易位系，用剂量为800、1200和1600拉德的60Coγ射线辐照硬粒小麦-绒毛草双二倍体。在辐照后第1、2和3天从穗上收集的花粉被转移到普通小麦品种‘中国春’的去雄穗上。利用基因组原位杂交技术鉴定M1代中的小麦-绒毛草染色体易位系。在BC1、BC2和BC3代中分析已鉴定的易位染色体的传递情况。结果表明，所有这三种辐照剂量在诱导小麦-外源易位方面都非常有效，且不影响M1种子的活力。在800-1600拉德范围内，随着辐照剂量的增加，易位诱导效率和中间染色体断裂-融合频率均增加。与辐照后第2天或第3天收集的花粉相比，使用辐照后第1天从穗上收集的花粉观察到更高的易位诱导频率。在M1代中检测到的超过70%的易位系通过雌配子传递到BC1代。在BC1代中获得的所有易位系在随后的BC2和BC3代中也都能获得。不同易位类型在不同遗传背景下通过雄配子或雌配子的传递能力表现为‘全臂易位＞小外源片段易位＞大外源片段易位’。一般来说，通过雌配子的传递能力高于通过雄配子的传递能力。通过这种方法，利用EST-STS标记在BC3代中鉴定出了14个涉及绒毛草不同染色体的易位系，其中8个是纯合的。
