Establishment and Inheritance model of dominant genic and cytoplasmic male sterility line DGCMS-3A with double low quality in Brassica napus L.

Chinese. 验证显性核不育两用系与波里马三系的基因型，明确Gd1AB和D3AB显性核不育的遗传模式，并构建显性细胞核+细胞质不育系统。通过显性核三系与波里马三系相互杂交验证其基因型，分析Mf和Rfc基因的等位性，采用临保系与显性纯合两用系×显性核不育恢复系F2代核不育株测交的方法，推论显性纯合两用系Gd1AB和D3AB的遗传控制模式。C3B为轮回父本与不育胞质的显性核不育株定向回交，以创建显性核不育+细胞质不育。鉴别了Gd1AB和D3AB的遗传控制模式，确定甘蓝型油菜显性纯合两用系Gd1AB由一对复等位遗传模式控制，而显性纯合两用系D3AB由两对基因互作控制。初步构建出双低显性杂合核不育+细胞质不育系统DGCMS-3A，并证实了选育显性纯合核不育+细胞质不育系的可行性。显性抑制基因Mf与波里马恢复基因Rfc不等位，Gd1AB的基因型为N（MsMsrfcrfc）×N（MsMfrfcrfc）)，D3AB的基因型为N（MsMsmfmfrfcrfc）×N（MsMsMfmfrfcrfc）。显性核不育+细胞质不育可细分为四种遗传模式：双位点互作显性杂合核不育+细胞质不育[S（Msmsmfmfrfcrfc）+S（msmsmfmfrfcrfc）]、单位点复等位显性杂合核不育+细胞质不育[S（Msmfrfcrfc）+S（mfmfrfcrfc）]、双位点互作显性纯合核不育+细胞质不育[S（MsMsmfmfrfcrfc）+S（MsMsMfmfrfcrfc）]、单位点复等位显性纯合核不育+细胞质不育[S（MsMsrfcrfc）+S（MsMfrfcrfc）]。

English. The dominant genic and cytoplasmic male sterility (DGCMS) in Brassica napus might be a new way in breeding program and utilization of heterosis. The present study was designated to verify the genotype of dominant male sterility two-line and Polima CMS three lines, identify the genetic pattern of dominant male sterility of Gd1AB and D3AB, construct dominant genic and cytoplasmic male sterility system. Various types of testcrosses and backcrosses were made between dominant male sterility two-line and Polima CMS three lines, and the fertility segregation was recorded, respectively, in ChongQing and/or ShiZhu country in spring and summer seasons. The allelism between the Mf in Gd1AB or D3AB and Rfc in Polima CMS restorers was analyzed. The testcrosses were made through crossing Gd1A or D3A with dominant restorers 05R or D1R, and the sterile plants of F2 with temporary maintainer test methodology were subjected to determine the genetic pattern of dominant homozygous two-type line Gd1AB or D3AB. The sterile plants with Polima CMS cytoplasm were selected to pollinate with C3B as recurrent parent, extensively screening in testcross progenies was made to find dominant nucleus + cytoplasm twin-ms lines. The testcross populations containing only sterile individuals clearly indicated the multiple allele inheritance model for Gd1AB was confirmed, and then the fact that testcross lines segregated for feitility strongly supported D3AB was conditioned by two dominant interactive genes rather than by multiple alleles. The dominant hyterozyous genic and cytoplasmic male sterility line DGCMS-3A was successfully obtained by continuous recurrent selection cross toward higher quality trait with low erucic acid and low glucosinolate for two years. By temporary maintainer test methodology, it was possible to select dominant homozygous genic male sterility with Polima CMS cytoplasm by recurrent selection through crossing Gd1B or D3B. The inhibitory gene Mf in the fertile plants from Gd1AB or D3AB was demonstrated to be nonallelic to the gene Rfc from Polima CMS restorers. The genotype of the sterile and fertile plants in Gd1AB are N (MsMsrfcrfc) and N (MfMsrfcrfc), respectively, while D3AB are of genotypes N (MsMsmfmfrfcrfc) and N (MfMsmfmfrfcrfc), respectively. Therefore, the dominant genic and cytoplasmic male sterility were separated into four kinds: the two dominant interactive hyterzygous genic and cytoplasmic male sterility S (Msmsmfmfrfcrfc) +S (msmsmfmfrfcrfc), the single multiple allelic heterozygous genic and cytoplasmic male sterility S (Msmfrfcrfc) +S (mfmfrfcrfc), the two dominant interactive homozygous genic and cytoplasmic male sterility S (MsMsmfmfrfcrfc) +S (MsMsMfmfrfcrfc), the single multiple allelic homozygous genic and cytoplasmic male sterility S (MsMsrfcrfc) +S (MfMsrfcrfc).