Using molecular markers to assist in the selection of the rice blast resistance genes Pi1, Pi2, and Pi-ta in rice wide compatibility restorer lines

Abstract

Hybridization was performed between the rice materials carrying the rice blast resistance genes Pi1, Pi2, and Pi-ta (R283) as the maternal parent and the broad compatibility restorer line R110 as the paternal parent. Molecular marker-assisted breeding techniques were used to detect the target genes in segregating generations. Through field selection and resistance identification, three stable lines with multiple resistance, strong restorer ability, and excellent agronomic traits were bred. Their agronomic and economic traits were analyzed along with their resistance to different physiological races of rice blast. These three stable lines were then crossed with seven different sterile lines (Chunjiang 23A, FA1, FA3, FA4, 81, 57, and 212A) to analyze the agronomic traits and resistance to rice blast pathogens in the hybrid combinations. JR11, JR12, and JR13 were stable, homozygous polymerized lines carrying Pi1, Pi2, and Pi-ta resistance genes and exhibited resistance frequencies ranging from 90.19 to 96.08% against different physiological races of rice blast disease. This indicates the excellent resistance of these three stable lines to rice blast disease. The seed-set frequencies in the hybrid combinations of the seven sterile lines with the three stable lines ranged from 66.4 to 84.1%, showing strong recovery ability. The yield of the selected combination of 23 A/JR11, 81 A/JR11, and 212 A/JR13 was 2.2–2.3% higher than that of the control Yongyou 1540. The research results showed that the three stable aggregated rice blast resistance genes Pi1, Pi2, and Pi-ta rice restorer lines created have good practical value in production.