Distribution of Rice Blast Resistance Genes Pitaand Pikm in Japonica Rice Germplasm Resources and Their Relationship with Rice Blast Resistance
LIU Haolin
SHEN Wenjuan
GAO Yu
QI Jingyi
LIU Hairui
GUAN Ruijie
MA Yu
ZHANG Tianchang
ZHANG Yinxia
Abstract：The blast resistance of 93 japonica rice germplasms,including local germplasms and introduced germplasms in Ningxia Hui Autonomous Region,was identified.Molecular detection of two rice blast resistance genes,Pita and Pikm,was conducted to analyze their genotypes.Subsequently,correlation analysis was performed between the comprehensive index of resistance and the resistance genes Pita and Pikm.The objective of this study was to provide a theoretical basis for rice blast-resistant breeding in Ningxia Hui Autonomous Region.The results showed that among the 93 germplasms,highly susceptible,moderately susceptible,susceptible,moderately resistant and resistant germplasms accounted for 2.2%(2/93),32.2%(30/93),6.5%(6/93),55.9%(52/93)and 3.2%(3/93),respectively.A total of 55 germplasms had resistance to rice blast,with resistance rate of 59.1%.Molecular detection results showed that there were 42 homozygotes for Pita resistance gene,accounting for 45.2%of the total germplasms.For Pikm resistance gene,there were 39 homozygotes,accounting for 41.9%of the total germplasms.The gene combination Pita+/Pikm+exhibited the best performance in enhancing resistance to rice blast,with an average comprehensive index of rice blast resistance of 2.63,followed by Pita+/Pikm-and Pita-/Pikm+,with average comprehensive indices of rice blast resistance of 4.08 and 4.42,respectively.In contrast,the resistance of gene combination Pita-/Pikm-was the weakest,with a comprehensive index of rice blast resistance of 5.33.The correlation analysis result showed that Pita and Pikm genes were significantly positively correlated with rice blast resistance,and there was also a significantly positive correlation between Pita and Pikm genes,indicating the presence of a synergistic effect of resistance between Pita and Pikm genes.Thus,integrating Pita and Pikm genes in molecular-assisted breeding programs against rice blast can improve the resistance to rice blast in Ningxia Hui Autonomous Region.
Keywords：Rice blastPitaPikmGenotypeResistance analysis
Publication Date：2025-02-15
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：11( 10-20 )