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

• Published in: Plant breeding Vol. 126; no. 5; pp. 541 - 547
• Main Authors: Li, Y.B, Wu, C.J, Jiang, G.H, Wang, L.Q, He, Y.Q
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.10.2007; Blackwell Publishing Ltd; Blackwell
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; digenic interactions; dynamic behaviour; Fundamental and applied biological sciences. Psychology; Genetics and breeding of economic plants; Magnaporthe grisea; Oryza sativa; Pyricularia grisea; QTL-by-environment interactions; QTLs; Varietal selection. Specialized plant breeding, plant breeding aims; Monocotyledones; Plant pathogen; Gene interaction; Mycosis; digenic interactions; Cereal crop; Fungi; Oryza sativa; Gramineae; Angiospermae; Ascomycetes; Fungi Imperfecti; Thallophyta; Pyricularia grisea; Dynamic characteristic; Oryza saliva; QTLs; Infection; Quantitative trait loci; Resistance; Magnaporthe grisea; Genotype environment interaction; Genetic improvement; dynamic behaviour; Spermatophyta
• ISSN: 0179-9541; 1439-0523
• DOI: 10.1111/j.1439-0523.2007.01409.x

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 resistance-breeding and map-based cloning of quantitative traits.