Author：Tsai, C. H.^1,*, Ann, P. J.¹, and Deng, W. L.²

Abstrct：

    In 2014, Pear blossom blast in imported pear scions was first found in Sanshing township, Yilan county. The abnormal sunken black spots were observed in the surface of some pear scions imported from Japan. The internal tissues of the diseased scions showed necrotic spot symptom. The bacteria isolated from necrotic tissues of the scions were identified as Pseudomonas syringae pv. syringae. The bacteria can cause blossom blast, bud blight, leaf spot symptoms and so on. When weather favors disease development, the disease could result in reducing yields significantly. In diagnosis, the bacteria isolated from infected scions on King’s B medium could test the hypersensitive reaction in tobacco plant. The bacteria can be further identified as Pseudomonas syringae based on Biolog, 16S rDNA sequence analysis and specific primers. The pathovar syringae of P. syringae can be tested by inoculation of the bacteria on pear, lilac, and bean pod. For avoiding economic loss, 4 emergency agrochemicals were selected for the disease control.

Keywords: pear scion, pear blossom blast, Pseudomonas syringae pv. syringae

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¹ Division of Plant Pathology, Agricultural Research Institute, COA
² Department of Plant Pathology, National Chung Hsing University
* Corresponding Author, e-mail: tsaich@tari.gov.tw

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