利用MAS技术改良香稻‘R15’的直链淀粉含量

Reducing Amylose Content of Aromatic Rice Variety ’R15’ By Molecular Marker-Assisted Selection

R15是适应性较广,产量较高的中熟晚籼香稻品系,但由于含有Wx^a基因,其直链淀粉含量高达23.5%,严重影响食用口感。因此,我们以含有Wx^b等位基因的不育系Y58S为供体,通过杂交、回交,利用RAD测序技术、分子标记辅助筛选等技术,经过8个世代的筛选,成功用Wx^b基因替换掉R15中的Wx^a基因,培育出1个新的纯合株系——‘深华R16’,其染色体上有10882234 bp长度的碱基,基因型和供体亲本‘Y58S’一致,占2.92%;有362363285 bp长度的DNA片段基因型和受体亲本‘R15’一致,占97.08%;其直链淀粉含量为14%。将‘Y58S’分别与‘深华R16’和‘R15’进行组配,结果表明,‘Y58S’/‘深华R16’组合的直链淀粉含量(13.9%)低于‘Y58S’/‘R15’组合的直链淀粉含量(19.9%),其它米质性状与农艺性状基本一致。本研究为分子标记辅助育种提供了新思路,培育出一新的水稻品系。

R15 is a mid-maturing late-season aromatic rice variety with broad adaptability and high yield.However,its amylose content is 23.5%,that affecting its eating taste.Wx^a gene mainly lead to its high amylose content.We used the sterile line’Y58 S’(Wx^b)as the donor,supported by restriction-site associated DNA(RAD)and molecular marker-assisted selection(MAS),to substituted Wx^a allele in’R15’.After 8 generations of screening,the Wx^a gene in’R15’was successfully replaced by Wx^b gene,and a new homozygous strain,’Shenhua R16’,was developed,which has 10882234 bp gonome came from the donor parent’Y58 S’,accounting for 2.92%;and 362363285 bp genome came from the recipient parent’R15’,accounting for 97.08%;its amylose content was 14%.The combination of’Y58 S’/’Shenhua R16’and’Y58 S’/’R15’showed that the amylose content of the combination of’Y58 S’/’Shenhua R16’(13.9%)was lower than the amylose content of the combination of’Y58 S’/’R15’(19.9%).Their rice quality traits(excepting AC)and agricultural traits are basically consistent with each other.The study offers an new trian of though for breeding,and cultivates an new rice varieties.