Characterization of Rice Blast Resistance Gene Pi61(t) in Rice Germplasm

Abstract

Ma, J., Jia, M. H., and Jia, Y. 2014. Characterization of rice blast resistance gene Pi61(t) in rice germplasm. Plant Dis. 98:1200-1204.Identification of resistance (R) genes to races of Magnaporthe oryzae in rice (Oryza sativa) germplasm is essential for the development of rice cultivars with long-lasting blast resistance. In the present study, one major quantitative trait locus, qPi93-3, was fine mapped using a recombinant inbred line (RIL), F 8 RIL171, derived from the cross between 'Nipponbare' and '93-11'. RIL171 contained a heterozygous qPi93-3 allele which was found to be resistant against nine U.S. common races-ID1, IA1, IB49, IE1, IA45, IB1, IC17, IB45, and IH1-of M. oryzae. An F 2 mapping population consisting of 2,381 individuals derived from RIL171was evaluated with a field isolate (race) ARB82 (IA1) of M. oryzae under greenhouse conditions. Disease reaction of a resistant/susceptible ratio of 3:1 was identified with F 2 :F 3 families. In total, 12 simple sequence repeat markers spanning qPi93-3 were used for fine mapping. Consequently, qPi93-3 was delimited to 4.2 Mb between RM3246 and RM7102. Three insertion-deletion (InDel) markers located between RM3246 and RM7102, that had previously used to map Pi61(t), showed that qPi93-3 was Pi61(t). The existence of Pi61(t) in 136 rice germplasm lines from the United States Department of Agriculture rice core collection was evaluated using Pi61(t)-specific InDel markers. Pi61(t) was identified as a source of resistance in 5 of the 136 lines. The characterized germplasm will be useful for rice breeders to use for improving blast resistance.Rice blast, caused by the filamentous fungal pathogen Magnaporthe oryzae, is one of the most devastating diseases that reduces rice yield around the world. Reliance on host resistance (R) is the most economical and environmentally friendly strategy to control rice blast. After the first blast R gene, Pia, was identified in 1967 (14), about 100 blast R genes have been mapped on rice chromosomes (1,22). Blast R genes were found in all chromosomes except chromosome 3, and some of them are clustered (i.e., chromosomes 6, 11, and 12) (1,18,22). However, major R genes are often rapidly overcome by new virulent M. oryzae isolates. Efforts have been made worldwide to identify a broad spectrum of resistance to blast (3,18).In many crops, the majority of traits are regulated by multiple genes rather than a single gene. These multiple genes, each with a relatively minor effect, are referred to as quantitative trait loci (QTLs; 4). Identification and mapping QTLs is an important strategy to discover blast R genes. Up to now, about 350 QTLs for blast resistance have been identified, and a few have been validated (1). In addition, 23 blast resistance genes have been mapped on rice chromosomes within identified QTL regions (22). DNA markers tightly linked to known R genes are vital for breeding via a marker-assisted selection (MAS) approach. Pik-m and Pik were differentiated by allele-specific DNA markers (2), while Pi-z and Pi-b were iden...

Breeding a series of new rice restorer lines with blast resistance and low‐to‐intermediate apparent amylose contents by integrating marker‐assisted and phenotypic selection

“…From 2008 to 2021, a total of 153 hybrid varieties derived from Huazhan have been released in China (http://www.ricedata.cn/variety/). These two restorer lines were previously reported to contain multiple R genes and confer resistance to many Magnaporthe oryzae strains (Lei et al., 2013; Ma et al., 2014; Tian et al., 2016; Wu et al., 2017; Xiao et al., 2020; Yang et al., 2009). However, we found both of them showed moderately to highly susceptible reactions in some blast hotspots of Hunan province, China, in recent years, whereas Gumei 4, the donor of Pigm , displayed stable resistance to rice blast (Y.…”

Identification of the blast resistance gene Picl(t) from Chaling common wild rice (Oryza rufipogon Griff.)

“…It was reported to show resistance to most of the tested M . oryzae isolates collected from China and United States (Lei et al, 2013; Ma, Jia, & Jia, 2014; Yang, Lin, Wang, & Pan, 2009). Three resistance genes, including Pi41 , Pi60(t) and Pi61(t) , were identified from 93‐11 (Lei et al, 2013; Yang et al, 2009).…”

“…States (Lei et al, 2013;Ma, Jia, & Jia, 2014;Yang, Lin, Wang, & Pan, 2009). Three resistance genes, including Pi41, Pi60(t) and…”

Genome-wide association study of rice genes and loci conferring resistance to Magnaporthe oryzae isolates from Taiwan

“…The QTL interval was the size of the significant LD block. Each candidate QTL (significant LD block) was checked for known R genes/loci in review papers (Ashkani et al 2016; Sharma et al 2012) and recent literature (Kang et al 2016; Liu et al 2015; Ma et al 2014, 2015; Mgonja et al 2016; Su et al 2015; Xu et al 2014; Zhao et al 2011; Zhu et al 2016). Previously identified blast QTLs and defense-related candidate genes were also checked according to the reference Nipponbare genomic sequences (MSU7) in the Gramene database (http://www.gramene.org/), Rice Genome Annotation Project website (http://rice.plantbiology.msu.edu/) (Kawahara et al 2013), and The Rice Annotation Project website (http://rapdb.dna.affrc.go.jp/index.html) (Kawahara et al 2013; Sakai et al 2013).…”