分子标记辅助选择培育低直链淀粉含量抗除草剂水稻

Cultivation of Herbicide Resistance Rice with Low Amylose by Molecular Marker-assisted Selection

为了提高水稻的食味品质和生产实践,培育了低直链淀粉含量和抗咪唑啉酮类除草剂2种性状兼顾的水稻新品系。利用带有低直链淀粉含量的南粳9108作为软米基因的供体,与显性核不育分离群体中不育单株进行杂交,并用南粳9108作为轮回亲本回交2次得到BC_(2)F_(1)群体,利用Wx-mq基因存在单核苷酸变异,对BC_(2)F_(1)群体的单株进行四引物扩增受阻突变体系PCR(Tetra-primer ARMS-PCR)扩增,依据其PCR产物带型可以准确区分Wx-mq纯合基因型、Wx-mq杂合基因型、非Wx-mq纯合基因型,筛选出农艺性状优良带有低直链淀粉含量的不育和可育单株;然后利用带有抗咪唑乙盐酸基因(Acetolactate Synthase,ALS)的金粳818作为抗除草剂基因的供体,与筛选出的带有低直链淀粉含量的不育单株进行杂交得到F_(1)群体,利用编码区ALS基因的碱基变异,进行等位基因特异PCR(AS-PCR)扩增,筛选出抗除草剂纯合基因型、感除草剂纯合基因型、抗除草剂杂合基因型。经ARMS-PCR鉴定结果表明,BC_(2)F_(1)不育群体中检测得到172株单株带型与南粳9108一致,含有糯性基因,性状为糯性;160株单株不含糯性基因;468株单株带型为双亲的杂合基因型。通过AS-PCR进行除草剂抗性鉴定,结果表明,在F_(1)群体1200个单株中,检测得到868个抗除草剂单株和332个感除草剂单株,其中纯合基因型624个,杂合基因型576个。经过逐代低直链淀粉含量和抗除草剂分子标记的选择,在F_(5)选育出同时具有除草剂抗性的低直链淀粉含量的水稻新品系6个。

In order to improve the taste quality and production practices of rice,a new rice line with both low amylose content and imidazolinone herbicide resistance was developed.Nanjing 9108 which with low amylose content was used as gene donor to cross with the sterile single plant selected from the dominant male sterile isolation population.Nanjing 9108 was used twice to backcross with the hybrid products to construct BC_(2)F_(1)population.Tetra-primer ARMS-PCR was used to analyze BC_(2)F_(1)population taking advantage of the SNP(Single Nucleotide Polymorphism)in Wx-mq gene.It could be accurately distinguished the Wx-mq homozygous genotype,Wx-mq heterozygous genotype and Wx-mq homozygous genotype according to the PCR results.The sterile and fertile single plants with low amylose content were screened out.Then Jinjing 818 with Acetolactate Synthase gene(ALS)was used as the donor parent of herbicide resistance gene to cross with the selected sterile single plant with low amylose content.The allele-specific PCR(AS-PCR)was used to amplify F_(1)according to the SNP in the coding regions of ALS gene to screen out herbicide resistance homozygous genotype,susceptible herbicide homozygous genotype and herbicide resistance heterozygous genotype.The results of ARMS-PCR identification showed that 172 single plant band patterns detected in the BC_(2)F_(1)sterile population were consistent with those of Nanjing 9108,containing waxy genes and waxy traits;160 individual plants didn′t contain glutinous genes;468 individual plants had a heterozygous genotype for parents.The herbicide resistance was identified by AS-PCR.The results showed that among 1200 individual plants of F_(1)population,868 individual herbicide resistant plants and 332 individual herbicide sensitive plants were detected.There were 624 homozygous genotypes and 576 heterozygous genotypes.The 6 new rice lines with low amylose content and herbicide resistance were gained in F_(5)generation after the selection using the molecular marker with low amylose content and herbicide resistance.