|Sdoode, R - PR SONGKLA UNIV/THAILAND|
|Teakle, D - QUEENSLAND UNIV/AUSTRALIA|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 11, 1996
Publication Date: N/A
Interpretive Summary: Many virus diseases are important because they occur worldwide. Maize stripe tenuivirus (MStV) is found in many tropical and subtropical regions worldwide. However, MStV has not been reported from the southeastern Asia continent. Microscopic and serological evidence are presented that indicate MStV occur in Thailand. Knowledge about the distribution, virulence and variability of these widespread viruses are necessary for developing disease control strategy.
Technical Abstract: Maize stripe tenuivirus (MStV) and its planthopper vector, Peregrinus maidis, occur in many tropical and subtropical regions worldwide (2). However, MStV has not been reported from the southeastern Asia continent. In January 1990, 5/200 Sorghum bicolor plants growing in Hat Yai, Thailand, showed symptoms typical of MSt, i.e. chlorotic spots, streaks and wide bands on the younger leaves. Colonies of P. maidis also were present in leaf whorls of both symptomatic and asymptomatic sorghum plants. In December 1991, two sweet corn plants (Zea mays cv. Thai Super Sweet Composit 1 DMR) growing in the same area showed similar symptoms and were infested with P. maidis. When examined by phase-contrast microscopy, sap from chlorotic leaf tissue of one sweet corn plant had needle-shaped crystals typical of MStV infection (1). Sap from asymptomatic sweet corn plants had no crystals. In April 1996 maize cv. Chieng Mai 90 with MSt-like symptoms and also infested by P. maidis was collected from Hat Yai. Leaves were freeze-dried, sent to Ohio, and tested by F(ab')2 ELISA. Positive control samples were fresh or freeze-dried leaves of sweet corn infected with MStV from Australia, Costa Rica, Malawi, Mauritius and the US. Leaves of asymptomatic glasshouse-grown sweet corn seedlings were negative controls. In the ELISA tests, the A405 values of the Thailand sample with MSt symptoms averaged 1.00, compared to 0.33 to 1.52 for the positive control samples, and 0.00 to 0.02 for fresh or freeze-dried negative controls. The microscopic and serological results indicate the occurrence of MStV in Thailand. However, a serological relationship between MStV and rice stripe virus is reported (2) and further studies are needed to confirm this observation.