Dynamic analyses of rice blast resistance for the assessment of genetic and environmental effects

Abstract

A doubled haploid population was employed to characterize the dynamic changes of the genetic components involved in rice blast resistance, including main-effect quantitative trait loci (QTLs), epistatic QTLs and QTL-by-environment interactions. The study was carried out at three different developmental stages of rice, using natural infection tests over 2 years. The number of main-effect QTLs, epistatic QTLs and their environmental interactions differed across the various measuring stages. One QTL (d12) on chromosome 12 was detected at all stages, whereas most QTLs were active only at one or two stages in the population. These findings suggest that the unstable expression of most QTLs identified for blast resistance was influenced by the developmental status of the plants, epistatic effects between different loci and the environments in which they were grown. These findings demonstrate the complexity of expression of rice blast resistance and have important implications for durable resistancebreeding and map-based cloning of quantitative traits.

Positive selection pressure on rice blast resistance allelePiz-tmakes it divergent in Indian land races

“…Rice blast (Magnaporthe oryzae) is one of the most serious diseases of rice, causing significant yield loss globally because of the complexity related to pathogen, host, and microclimate (Teng et al 1991;Kwon & Lee 2002;Li et al 2007). Different variants of this fungus have fast evolved in most of the field conditions, because of its sexual and asexual nature of reproduction (Xia et al 1993).…”

Screening of Rice Blast Resistance Genes from Aromatic Rice Germplasms with SNP Markers

“…Rice blast disease, caused by Magnaporthe grisea, causes economically significant yield losses annually worldwide and has been one of the most serious diseases of rice because of their pathogenic complexity related pathogen, host, and micro weather (Kwon and Lee, 2002;Lee, 1994;Li et al, 2007;Ou, 1985;Teng et al, 1991).…”

Mapping of QTLs involved in resistence to rice blast (Magnaporthe grisea) using Oryza minuta introgression lines

“…Genetic studies of field resistance have been conducted using rice cultivars since the 1970s. Most studies (Higashi & Kushibuchi 1978;Maruyama et al 1983;Higashi & Saito 1985;Wang et al 1994;Nagato & Yoshimura 1998;Ahn et al 2000;Hayashi et al 2004;Zhou et al 2004;Wu et al 2005;Gowda et al 2006;Li et al 2007Li et al , 2008 showed that field resistance to blast is complex and controlled by multiple genes with complementary or additive effects (He et al 1989), as well as their environmental interactions (Bonman 1992). To characterize field resistance genes, genome information and the materials with a genetic background are necessary (Fukuoka & Okuno 2001).…”