Pi-ta、Pi-5、Pi-km和Pi-b基因在粳稻品种(系)中的分布及对穗颈瘟的抗性

Distribution of Pi-ta,Pi-5,Pi-km and Pi-b genes in japonica rice varieties(lines) and their relationship with neck blast resistance

利用稻瘟病抗性基因Pi-ta、Pi-5、Pi-km、Pi-b的功能标记,对国内外238份粳稻品种(系)进行基因检测,结合穗颈瘟鉴定结果,明确4个抗性基因的区域分布特点,评估其对穗颈瘟的抗性效果。Pi-ta和Pi-b主要分布在东北、长江中下游及西南地区品种(系)中,Pi-5和Pi-km在西南地区品种中的分布高于其他地区。238份粳稻品种(系)中含Pi-ta、Pi-5、Pi-km、Pi-b单个抗性基因的品种(系)分别有33、30、29和38份;含2个抗性基因的品种(系)共有66份,其中含Pi-ta/Pi-b的品种(系)最多,有28份;同时含3个抗性基因的品种(系)有12份; 4个基因均不含有的品种(系)有30份。Pi-ta对穗颈瘟的抗性效果最好,感病率为0,病情指数为22. 73;其次是Pi-5和Pikm基因,病情指数分别为59. 17和70. 69; Pi-b对穗颈瘟的抗性效果最差,感病率为86. 84%,病情指数为83. 55。双基因组合对穗颈瘟的抗性效果依次为:Pi-ta/Pi-5>Pi-ta/Pi-km>Pi-ta/Pi-b>Pi-5/Pi-km; 3份同时含有Pi-ta、Pi-5、Pi-km 3基因的品种表现出最强的穗颈瘟抗性。

To state the region distribution of Pi-ta,Pi-5,Pi-km,Pi-b genes and their relationship with neck blast resistance,238 japonica rice varieties(lines)from different regions of China and abroad were genotyped using the functional markers of the four genes and their disease reactions were detected to evaluate the effects of these genes on the resistance of neck blast.Pi-ta and Pi-b distributed in the Northeast,the middle and lower reaches of the Yangtze River and Southwest of China,while Pi-5 and Pi-km were more inclined to the Southwest China than other regions.Moreover,33,30,29 and 38 varieties(lines)were detected to carry the single gene of Pi-ta,Pi-5,Pi-km and Pi-b,respectively.A total of 66 varieties(lines)carried two resistance genes and there were 28 varieties(lines)harboring Pi-ta/Pi-b which was much higher than other gene combinations.There were 12 varieties(lines)carrying three resistance genes Pi-ta,Pi-5 and Pi-km.Thirty varieties(lines)were detected with no resistance gene.Pi-ta gene had the best effects to neck blast resistance with a prevalence of 0 and a disease index of 22.73,followed by Pi-5 and Pi-km genes with a disease index of 59.17 and 70.69,respectively.The resistance of Pi-b gene was the lowest among them with a prevalence of 86.84 and a disease index of 83.55.The effects of double genes to neck blast resistance showed that Pi-ta/Pi-5>Pi-ta/Pi-km>Pi-ta/Pi-b>Pi-5/Pi-km.Three varieties containing Pi-ta/Pi-5/Pi-km genes were detected and showed the strongest effects to neck blast resistance.