长江中下游地区粳稻稻瘟病基因型与苗瘟抗性分析

稻瘟病是对水稻威胁最严重的病害之一。为明确抗性基因与稻瘟病抗性之间的关系,通过对153份粳稻审定品种或试验品系中的12个稻瘟病抗性基因进行分子检测,结果表明,Pib基因在供试材料中占比最高,达到77.12%,其次为Pita、Pi54和Pb1,分别达到41.83%、36.6%和36.6%,Pikm、Pik、Pia、Pid3、Pi5、Pid2和Pizt基因的出现频率在11.76%~24.18%之间,供试材料中未发现Pi25基因分布。利用安徽省不同生态区的稻瘟病优势生理小种混合菌株对153份供试材料进行苗期人工接种鉴定,结果显示,抗病(0Pi5和Pia基因对苗瘟抗性贡献较显著,“Pi5+Pia”基因组合效应增强,携带“Pi5+Pia+Pik+Pikm”基因组合的材料,抗性更强;此外,“Pita+Pik+Pikm+Pb1”基因组合亦表现出较好的苗瘟抗性。这些结果表明,“Pia+Pi5”、“Pia+Pi5+Pik+Pikm”和“Pita+Pik+Pikm+Pb1”基因组合对改良安徽粳稻品种稻瘟病抗性具有潜在的应用价值。本研究结果对水稻抗性育种具有重要指导意义。

Associated Analysis of Rice Blast Genotypes and Seedling Blast Resistance of Japonica Rice Resources in the Middle and Lower Reaches of the Yangtze River

Rice blast is one of the most serious diseases for rice. In order to clarify the relationship between resistance genes and rice blast resistance, 12 rice blast resistance genes in 153 japonica rice varieties/lines were genotyped. The results showed that Pib gene was detected in 77.12% of the rice materials examined, followed by Pita, Pi54 and Pb1 genes, which accounts for 41.83%, 36.6% and 36.6%, respectively. In contrast, the distribution frequencies of Pikm, Pik, Pia, Pid3, Pi5, Pid2 and Pizt genes ranged from 11.76% to 24.18%, and Pi25 gene was not found in the tested materials. Using the mixed strains of dominant physiological races of rice blast from varied ecological regions of Anhui Province, 153 rice materials were artificially inoculated and evaluated at the seedling stage. Six resistant (0Pi5 and Pia genes contributed significantly to seedling blast resistance. Pyramiding of both genes exhibited stronger rice blast resistance, and the resistance of materials carrying Pi5, Pia, Pik and Pikm genes could be further improved. In addition, we found that pyramiding of Pita, Pik, Pikm and Pb1 genes also displayed better seedling blast resistance. Taken together, these results suggested that “Pia+Pi5”, “Pia+Pi5+Pik+Pikm” and “Pita+Pik+Pikm+Pb1” combinations may be useful gene pyramiding strategies in rice blast resistance breeding in Anhui Province. This study has important guiding significance for rice breeding.