Disease Note.

Detection of Dasheen Mosaic Virus from Taro Plants in the Field and in Tissue Culture. J. S. Hu, Department of Plant Pathology, University of Hawaii, Honolulu 96822. S. Meleisea, and M. Wang; Rachael Reolanei, Kea'au Plantation Lab, Hilo, HI 96720. Plant Dis. 78:754. Accepted for publication 28 February 1994. Copyright 1994 The American Phytopathological Society. DOI: 10.1094/PD-78-0754A.

Fifty-four taro (Colocasia esculenta L. Schott) cultivars were tested in Hawaii for dasheen mosaic potyvirus (DsMV) using indirect ELISA with a monoclonal antibody against a shared epitope of potyviruses (MAb-PTY 1, R. Jordan, USDA-ARS), and with an anti-DsMV polyclonal antibody (F. Zettler, University of Florida). In repeated ELISA tests, DsMV was detected in 36 of 54 taro cultivars. Four of these cultivars—Bun Long (the Chinese table and chip taro), Lehua Maoli (a purple poi taro), Niue (a pink Samoan table taro), and Mana Lauloa (a white poi taro)—were selected by growers for propagation in tissue culture. Initially DsMV was detected from 8 of 27, 5 of 19, and 8 of 24 samples, respectively, of Niue, Mana Lauloa, and Lehua Maoli. None of 24 samples from Bun Long was positive in the ELISA. In two additional ELISA tests done 6 mo after (he initial test, DsMV was detected in the remaining 16 Lehua Maoli samples and in 12 more Niue samples, whereas all the Bun Long and Mana Lauloa samples were negative. These results indicate that DsMV is widespread in taro cultivars in Hawaii and that the apparent uneven distribution of DsMV in taro requires multiple sampling and ELISA tests for detection. To increase the likelihood that DsMV-free planting materials are obtained, different tissues should be sampled, and plants in tissue culture should be tested at least three times over 6 mo before being used to propagate material.