Pyramiding Rice Blast Resistance Gene Pi2 and Fragrance Gene badh2

Abstract

Rice is a major food crop across the globe, but the frequent occurrence of rice blast in recent years has seriously affected the yield of rice. In addition, fragrance rice is becoming increasingly popular among consumers. In this study, the fragrant rice variety Wenxiang-1 was used as the donor of the fragrance gene badh2, and the rice variety R1179 was used as the donor of rice blast resistance gene Pi2. Plants that were homozygous for both Pi2 and badh2 were selected using marker-assisted selection (MAS) applied to the Wenxiang-1/R1179 F2 segregation population with the functional markers Pi2-1 and Badh2-1 as well as whole-genome-SNP-genotyping technology. Finally, “elite” rice varieties R365 and R403 that had both high levels of rice blast resistance (level 3 and 4) and fragrance (0.650 and 0.511 mg/kg) were bred. Genetic composition analysis indicated that 40.67% of the whole genome of R365 was inherited from Wenxiang-1, while 59.33% was inherited from R1179. Similarly, 46.26% of the whole genome of R403 was inherited from Wenxiang-1, while 53.74% was inherited from R1179. These new hybrid lines with R365 and R403 as the male parents also exhibit high yield per hectare, especially C815S/R365 and Yu03S/R403 F1, with yields per hectare of 9.93 ± 0.15 and 9.6 ± 0.17 tons. These plants also possess high levels of rice blast resistance (level 3 and 4) and fragrance (0.563 and 0.618 mg/kg).