大葱离体雌核发育诱导单倍体研究

Study on Haploid Induction via in vitro Gynogenesis of Bunching Onion

以大葱未开放花蕾为试材,研究花蕾大小、培养基、外源激素浓度配比不同对大葱离体雌核诱导单倍体的影响,旨在建立大葱离体雌核发育诱导单倍体技术体系。结果表明:直径为2. 0～2. 5 mm的未开放花蕾为最适外植体;在MS培养基中添加1. 0 mg·L-12,4-D和1. 5 mg·L-16-BA时,其雌核发育胚诱导率可达3. 5%;在B5培养基中添加1. 0 mg·L-12,4-D和1. 0 mg·L-16-BA时,其雌核发育胚诱导率可达2. 5%。将雌核发育胚转移至不含外源激素的1/2MS培养基中诱导生根,可发育成完整植株。通过根尖染色体计数分析,136株再生植株中有15株为单倍体,单倍率11%。由单倍体加倍获得的双单倍体是重要性状遗传分析、分子标记及数量性状研究的理想材料,此研究可为大葱遗传育种奠定基础。

In order to establish a haploid induction system via in vitro gynogenesis in bunching onion,the different sizes of unopened flower buds were cultured in vitro using different culture medium and different concentrations of exogenous hormones.The results showed that the buds with diameter of2.0~2.5mm were suitable for culture in vitro.The suitable media for haploid induction were MS medium with1.0mg·L^-12,4-D+1.5mg·L^-16-BA and B5medium with1.0mg·L^-12,4-D+1.0mg·L^-16-BA,and the highest induction rates were3.5%and2.5%,respectively.The embryos could grow root and develop into complete plant in the1/2MS medium without exogenous hormones.Ploidy analysis of the regenerants with chromosome counts of root tip cells revealed that15of136plants were haploid and the rate was11%.Double haploids obtained by doubling haploids were ideal materials for genetic analysis of important traits,molecular markers and quantitative traits.This research has laid a foundation for genetic breeding of bunching onion.