水稻低直链淀粉含量基因Wxmq的KASP标记开发与利用

Development and Utilization of KASP Marker for Low Amylose Content Gene, Wxmq, in Rice（Oryza Sativa L.）

拥有低直链淀粉含量基因Wx^mq的软米具有适口和膨化性好、软而不烂、富有弹性、回生程度小、冷后不易变硬等优点。为了提高优质软米的选育效率,根据Wx^mq基因第4外显子的SNP1突变位点开发了一个高通量分子标记Wx^mq-KASP,利用该标记对粳稻软米品种‘南粳9108’、中等直链淀粉含量粳稻保持系‘申01B’及其杂交F2代群体进行基因分型,在F2群体83个单株中,有21个单株表现出与‘南粳9108’相同的基因型,20个单株与‘申01B’基因型相同,而42个单株表现为杂合基因型。利用前人开发的CAPS标记对‘南粳9108’、‘申01B’及其杂交F2群体的Wx基因进行了基因型检测,所得结果与Wx^mq-KASP检测结果完全一致。该研究表明KASP标记Wx^mq-KASP可以高效应用于水稻低直链淀粉含量种质资源鉴定及分子标记辅助选择育种。

Soft rice with low amylose content gene Wx^mq has the advantages of palatability,good puffing,soft but not rotten,elasticity,low degree of retrogradation and hardening after cold.In order to improve the breeding efficiency of soft rice with high quality,a high throughput molecular marker,Wx^mq-KASP,developed based on the SNP1 site in exon 4 of Wx^mq gene,was used to genotype the japonica rice variety‘Nanjing 9108’with low amylose content,japonica rice maintainer Line‘Shen01B’with medium amylose content and their F2 population.Of eighty-three individual plants in F2 population,21 and 20 individuals,respectively,have the similar genotype as‘Nanjing 9108’and‘Shen01B’,whereas 42 individuals were heterozygous.The genotype of‘nanjing 9108’,‘shen 01B’and their hybrid F2 population was also detected using the CAPS marker developed by predecessors,and the results obtained were completely consistent with the results of Wx^mq-KASP.This study indicated that KASP marker Wx^mq-KASP could be effectively applied in molecular marker-assisted selection breeding of low amylose content rice.