Journal of Taiwan Agricultural Research

Author:Szu-Yi Chou and Dah-Jing Liao*

Abstract:

    The present study was to analyze the changing trends of blast resistance and its relationship among rice cultivars/lines developed in 2009–2014. The information can be provided as a reference for breeders in planning breeding strategy in the future. The experimental materials included 1,195 rice cultivars/lines provided by the local 9 agricultural experimental agencies, and were examined for their responses to both leaf and panicle blast in the upland and the paddy nurseries located at Chiayi Agricultural Experimental Station of Taiwan Agricultural Research Institute. A susceptible cultivar ‘Lomello’ and a resistant cultivar ‘TNG70’ were used for reference checks, and were found stable to the responses of blast during the period of experiment, indicating that the conditions of nursery and results of examination were stale and reliable. There were 1,021 cultivars/lines of japonica type rice included in the experiment, and the ratio of expressing resistance to leaf and panicle blast in the paddy nursery were 65.23% and 43.39%, respectively. In the upland nursery, the ratio of expressing resistance to leaf blast in the first and the second cropping season were 48.58% and 49.27%, respectively. The other 174 cultivars/lines of indica type rice were also examined for their resistance performance to blast. It showed that ratio of expressing resistance to leaf and panicle blast in the paddy nursery were 96.55% and 90.23%, respectively. In the upland nursery, the ratio of expressing resistance to leaf blast in the first and the second cropping season were 95.98% and 96.55%, respectively. By further analyzing the experimental results, it showed that some cultivars/lines of japonica type rice varied in the responses to leaf and panicle blast. Among the cultivars/lines, about 22% were resistance to leaf blast while were infected by panicle blast. These cultivars/lines required further studied in the advanced field examination for their resistance to panicle blast. Since the susceptibility of a cultivar/line to blast will be more serious in upland nursey than in paddy condition, we suggest that upland nursery can be used for selection of blast resistance in the early stage of a breeding program so as to improve breeding efficiency. Results also showed that japonica type rice cultivars/lines perform differently in the upland nursery between the first and the second cropping seasons, while indica type rice cultivars/line have a consistent performance in both crop seasons.

Key words:Rice, Blast, Disease nursery

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