摘要
以20118A不育系和临保系与20个油菜品种(系)杂交测交后代为材料,采用经典遗传学和分子标记辅助选择方法,验证该不育系统遗传控制体系及等位基因分布频率;探索利用连锁共显性标记筛选两型系和临保系基因型的高效性和准确率。研究表明,6个品种(系)与20118A测交产生的F2世代,所有组合可育株∶不育株均符合3∶1或13∶3分离规律,而与20118A-TAM杂交产生的6个F2中1个呈13∶3分离,其余均为全可育,育性符合1对隐性不育基因和1对隐性上位抑制基因互作控制的遗传模式。进而采取反向验证方法,从1059个F2分离单株中,用新开发的Bnms3/Bnrf连锁共显性标记跟踪选择,直接获得临保系(ms3ms3rfrf)、纯合不育株(ms3ms3RfRf)和两型系可育株(Ms3ms3RfRf)70、69和135株,经测交或互交验证,准确率均达95%以上。根据20个测交品种的后代分离,BnRf位点上只出现Rf和rf两个等位基因,推测第3个等位基因存在的频率很低,基本可以根据两基因各2对等位基因互作原理开展分子标记辅助育种。
In the present study, 20 varieties/lines of Brassica napus were test-crossed with sterile line 20118A, and its temporary maintainer 20118A-TAM. Both traditional genetic analysis and molecular marker assisted technology were employed to confirm their genetic model of sterility with two-gene-control systems, to check the ailelic distributions among normal rapeseed varieties or lines. Furthermore, the efficiency and accuracy of marker-assisted selection （MAS） for two-type line and temporary maintainers based on co-dominant markers were also investigated. The results showed that the segregation proportion of male fertile to sterile plants in Fe progenies from six varieties （lines） crossed with 20118A fitted Mendelian segregation （3：1 and 13：3）, and that with 20118A-TAM showed either 13：3 or full male fertile, indicating that the sterility of 20118A is controlled by one recessive sterile gene interacting with a recessive epistatic suppression gene. In addition, a reverse validation approach based on Brims3 and Bnrf linked marker assisted selection was used to further confirm the two gene control system. In a total of 1059 F2 plants, 70, 69, and 135 individuals carrying temporary maintainer （msЗmsЗrfrf）, homozygous sterile （msЗmsЗRfRf） and fertile （MsЗmsЗRfRf） marker genotypes were screened out, respectively, which also fitted the Mendelian segregation proportions of two gene models （1/16, 1/16, and 1/8）. After test-crossing with known homozygous sterile plants or temporary maintainers or one another among marker genotypes, higher than 95% of lines were approved to be the expected genotypes. Finally, according to the information from 20 testcross cultivars/lines, only two alleles of Rfand rfwere observed on BnRflocus, implying the third allele naturally existed very few, if any. Therefore, for practical breeding purpose, a marker assisted selection strategy simply based on BnRf/rf and BnMsЗ/msЗ linked co-dominant markers is proposed.
出处
《作物学报》
CAS
CSCD
北大核心
2012年第11期2015-2023,共9页
Acta Agronomica Sinica
基金
国家高技术研究发展计划(863计划)项目(2011AA10A104)
浙江省科技厅重大专项(2011C12005)资助
关键词
甘蓝型油菜
隐性上位核不育
分子标记辅助选育
两型系
临保系
Brassica napus L.
Recessive genic male sterility
Molecular marker assisted selection
Two-type line
Temporarymaintainer
