稻瘟病抗性基因Pita在中日韩粳稻中的分布

为了解2 350份来源中国、日本和韩国粳稻品种(系)稻瘟病抗性基因Pita的分布,利用2个KASP分子标记对该基因进行了检测,605份材料表现有利,1 732份不利,7份为杂合,6份不确定。在有利、不利和杂合三个群体中分别随机选取316份、101份和7份材料,对Pita基因功能片段进行了测序分析,结果显示有利群体中KASP检测结果准确率为95.89%,不利群体100%,2个KASP分子标记可以用来联合检测水稻种质资源的Pita抗性基因。根据KASP分子标记检测结果,在中国北方地方稻种中仅0.69%品种携带Pita抗性基因,在中国13个省区市育成品种(系)和日本韩国外来稻种中均有一定的分布,频率7.02%~55.81%,表明Pita基因在东亚地区范围内均得到了一定的应用,但各地区应用程度相差较大,其中中国吉林、辽宁、宁夏、浙江四省地区较高。通过415份材料Pita基因功能片段609个碱基序列的比较,仅发现3个变异位点(第2 388位,第2 752位,第2 766位)和4种基因单倍型,其中抗性基因仅一种单倍型(H1),感病基因有三种单倍型(H2, H3, H4),H2为优势单倍型(84.84%)。本研究结果为开发和利用中日韩地区稻种资源和品种布局提供了依据。

Distribution of Pita Gene for Rice Blast Resistance in the Rice Cultivars(Lines) from China,Japan and Korea

The rice blast resistant Pita gene was detected by two KASP(kompetitive allele specific PCR) molecular markers to understand its distribution in 2 350 japonica cultivars(lines) from China, Japan and Korea. The results showed that 605 lines were favorable for the rice blast resistance, 1 732 unfavorable, 7 heterozygous, and 6 unknown types. Some cultivars were randomly selected to sequence the functional fragments of Pita gene from the favorable,the unfavorable and the heterozygous groups respectively. The results showed that these two KASP molecular markers could be used to jointly detect Pita resistance genes in the rice germplasm resources at the accuracy of95.89% in the favorable group and 100% in the unfavorable group. According to the results of KASP molecular marker, the Pita resistance gene was distributed at the frequency of 0.69% in the landraces from northern China,and 7.02%~55.81% in the modern breed cultivars or lines from 13 provinces(autonomous regions or municipalities)of China, Japan and Korea, and it indicated that the Pita gene was effective in the rice resistant breeding for rice blast in the East Asian region, especially in Jilin, Liaoning, Ningxia and Zhejiang provinces(autonomous regions)of China. Through the comparison of 609 bases sequence of Pita gene functional fragment, only three mutation sites(sites 2 388, 2 752 and 2 766) and 4 haplotypes(one resistant haplotype H1 and three susceptible haplotypes H2, H3 and H4) were found in 415 cultivars, and the haplotype H2 was the dominant haplotype(84.84%). The results of this study provide a basis for the development and utilization of these rice germplasm resources from East Asia and the variety layout in China.