Ting Mao, Mingdong Zhu, Shakeel Ahmad, Guoyou Ye, Zhonghua Sheng, Shikai Hu, Guiai Jiao, Lihong Xie, Shaoqing Tang, Xiangjin Wei, Peisong Hu, Gaoneng Shao

Mol Breed. J. 2021;41(10):65.  doi: 10.1007/s11032-021-01259-4. Epub 2021 Oct 8.

Abstract

Yanfeng 47 (YF47) is an elite japonica rice variety cultivated in China on nearly 2 million hectares over the past 20 years. However, YF47 is highly susceptible to rice blast (Magnaporthe oryzae), one of the most destructive rice diseases. In this study, we developed novel TPAP (tetra-primer ARMS-PCR) functional markers for the genes Pita, Pib, and Pid2, all of which afford broad-spectrum resistance to blast. A collection of 91 japonica rice germplasms with similar ecological characteristics to YF47 were screened, and Wuyunjing 27 (WYJ27) with Pita and Pib alleles and P135 with the Pid2 allele were identified. Furthermore, the corresponding positive Pita, Pib, and Pid2 alleles were transferred into YF47 using single, mutual, and backcrosses, together with molecular marker-assisted selection (MAS) and anther culture technology. These genetic materials, carrying one, two, or three functional alleles, were generated within 3 years, and compared to YF47, they all showed improved resistance to naturally inoculated rice blast. Further improved lines (IL) 1 to 5 (all containing Pita, Pib, and Pid2 alleles) were evaluated for yield performance, and when no fungicide was applied, all lines except IL-4 showed increased traits compared with those of YF47. IL-5, renamed Yanjing 144 (YJ144), showed yield increases in the Liaoning province regional variety comparison test and superior appearance quality compared to YF47. Our work provides a molecular design strategy for pyramiding multiple beneficial genes to rapidly improve rice blast resistance, yield, and quality using multiple breeding strategies.

See: https://pubmed.ncbi.nlm.nih.gov/34642568/

Fig. 1

TPAP primer design and detection of Pita, Pib, and Pid2 alleles. Design strategy for TPAP–Pita (A), TPAP–Pib (B), and TPAP–Pid2 (C) markers. Functional SNPs are shown in red; underlines show primer binding sites. PCR assay of Pita (D) between resistant (K103, lanes 1 and 3) and susceptible (LJHG, lanes 2 and 4) genotypes in two repeats; Pib (E) between resistant (K104, lanes 2 and 4) and susceptible (LJHG, lanes 1 and 3) genotypes in two repeats; Pid2 (F) between resistant (Digu, lanes 1 and 3) and susceptible (LJHG, lanes 2 and 4) genotypes in two repeats. M, marker 2000. G Genotype analysis of Pita, Pib, and Pid2 on 91 rice germplasm using TPAP–Pita, TPAP–Pib, and TPAP–Pid2. Nos. 1–2 are the resistance check and susceptibility check of Pita, Pib, and Pid2, corresponding to K013 and LJHG, K014 and LJHG, and Digu and LJHG, respectively; Nos. 3–48, 49–63, 64–67, 68–82, 83–87, and 88–91 are japonica germplasms collected from Liaoning, Ningxia, Tianjin, Xinjiang, Jilin, and Jiangsu provinces, respectively. The yellow regions represent susceptible genotypes, and the red regions represent the resistance genotypes YF47, Yanfeng47, and WYJ27, Wuyunjing27.