Four QTL in Rice Associated with Broad Spectrum Resistance to Blast Isolates from Rice and Barley |
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Authors: | Phinyarat Kongprakhon Alfonso Cuesta‐Marcos Patrick M. Hayes Vipa Hongtrakul Pattama Sirithunya Theerayuth Toojinda Nitsri Sangduen |
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Affiliation: | 1. Authors’ addresses: Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand;2. Department of Crop and Soil Science, Oregon State University, Corvallis, OR 97331, USA;3. Lampang Agriculture Research and Training Center (LARTC), Muang, Lampang 52000, Thailand;4. DNA Technology Laboratory, National Research Center for Genetic Engineering and Biotechnology, Kasetsart University, Kamphang Saen Campus, Nakhon Pathom 73140, Thailand (correspondence to Nitsri Sangduen. E‐mail: fscinss@ku.ac.th) |
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Abstract: | Pyricularia grisea is the most destructive and cosmopolitan fungal pathogen of rice and it can also cause disease on other agriculturally important cereals. We determined the number, location and interaction of quantitative trait loci (QTL) associated with resistance to P. grisea isolates obtained from rice (THL142 and THL222) and barley (TH16 and THL80) grown in Thailand. The isolates showed a spectrum of virulence when used to inoculate a series of differentials. We used a reference blast resistance mapping population of rice (IR64 × Azucena). IR64 was highly resistant, and Azucena was highly susceptible, to all four isolates. The numbers of resistant vs. susceptible progeny suggest that the resistance of IR64 is determined by two or three genes with additive effects. The correlation coefficients for all pairwise comparisons of disease severity were high and highest between barley isolates and between rice isolates. Four QTL were detected, one on each of the following chromosomes 2, 8, 9 and 10. IR64 contributed resistance alleles at three of the QTL (chromosomes 2, 8 and 9). Azucena contributed the resistance allele at the QTL on chromosome 10 in response to inoculation with isolate THL142. The results of the QTL analysis support interpretation of the phenotypic frequency distributions regarding the number of genes determining resistance to the four isolates in this population. Our results are novel in adding blast isolates from barley to the catalogue of pathogen specificities to which a gene, or genes, from IR64 confer resistance. |
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Keywords: | rice rice blast barley blast QTL |
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