Evaluation of Rice Blast Resistance and <i>R</i> Gene Analysis in <i>Japonica</i> Rice Varieties Tested in the Anhui Region
Rice blast caused by the ascomycete fungus <i>Magnaporthe oryzea</i> is one of the most widespread and destructive rice diseases worldwide. The most economical and effective strategy for controlling rice blast is the rational use and promotion of disease-resistant varieties. To enhance d...
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| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-04-01
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| Series: | Agronomy |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4395/15/5/1008 |
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| Summary: | Rice blast caused by the ascomycete fungus <i>Magnaporthe oryzea</i> is one of the most widespread and destructive rice diseases worldwide. The most economical and effective strategy for controlling rice blast is the rational use and promotion of disease-resistant varieties. To enhance disease resistance, it is essential to analyze the resistance levels of rice varieties and the role of resistance (<i>R</i>) genes. To investigate blast resistance, <i>R</i> gene distribution, and their contributions in <i>japonica</i> rice, 287 varieties were evaluated through artificial inoculation. PCR detection was also performed using specific primers for eleven <i>R</i> genes. The results showed that 24.4% of the varieties exhibited moderate resistance (MR), indicating an overall moderate resistance level. The frequency of <i>R</i> genes varied significantly: <i>Pib</i> was the most prevalent (89.2%), followed by <i>Pi5</i> (73.5%), <i>Pita</i> (62.4%), <i>Pia</i> (54.4%), <i>Pikh</i> (48.4%), <i>Pik</i> (41.1%), <i>Pi9</i> (35.5%), <i>Pizt</i> (23.7%), <i>Pit</i> (10.8%), and <i>Pi1</i> (10.5%). No <i>Pigm</i> was detected. Among these, <i>Pik</i>, <i>Pi9</i>, <i>Pizt</i>, and <i>Pita</i> contributed most significantly to disease resistance, with contributions of 42.4%, 38.2%, 38.2%, and 33.5%, respectively. The number of <i>R</i> genes detected in the tested varieties ranged from 0 to 9, with most varieties containing more than three genes. The highest proportion of resistant varieties was observed in those carrying six genes. The most common <i>R</i> gene combinations in resistant varieties were ‘<i>Pib</i> + <i>Pita</i> + <i>Pi5</i> + <i>Pikh</i> + <i>Pik</i> + <i>Pi9</i>’ and ‘<i>Pizt</i> + <i>Pib</i> + <i>Pita</i> + <i>Pia</i> + <i>Pi5</i> + <i>Pik</i> + <i>Pi9</i>’. In conclusion, these findings provide valuable insights into the breeding and utilizing blast-resistant <i>japonica</i> rice varieties in Anhui Province. |
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| ISSN: | 2073-4395 |