The identification and ecology of Aphelenchoides bicaudatus and Aphelenchoides sp. isolated from Phalaenopsis

• Main Authors: Fan-Yu Jain, 簡凡喻
• Other Authors: Tung-Tsuan Tsay
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/84769064385202878796

碩士 === 國立中興大學 === 植物病理學系所 === 98 === In this study, we surveyed the distribution of the foliar nematodes (Aphelenchoides) in 48 Phalaenopsis nurseriesfrom the central and southern Taiwan. Aphelenchoides could be found in up to 35 Phalaenopsis greenhouses among 48 surveyed, the radio was about 72%. Three Aphelenchoides population ABC, AU, AL were collected in this investigation. All of them had the typical characteristics of genus Aphelenchoides under the optical microscope. The nematode body was linear, with the stylet and the stylet knob, three parts of esophagus, the width of the median esophageal bulb was more than 75% of the body width. Female had single-ovary with the posterior uterine branch. Based on external morphology and measurement of De Man’s formula could determine the ABC isolate to be Aphelenchoides bicaudatus, the AU and AL were similar to Aphelenchoides composticola. The region of 18S rDNA of three Aphelenchoides isolates, compared with the Genebank database system, confirmed ABC isolate was Aphelenchoides bicaudatus. AU and AL have 99% similarity, but their sequences were not similar to any of species data in Genebank, however, they shares no similarity with the 4 major Aphelenchoides species. Three Aphelenchoides isolates (AU, AL, ABC) could successfully infect orchid by inoculating 1000 nematodes on roots by pricking wounds. The nematodes and eggs could be observed in the root 1 month later, which revealed that these nematodes could complete their life cycle in the roots. Three Aphelenchoides populations isolated from orchid could penetrate to rice and strawberry. Inoculating Dendrobium miyakei Schlt., Asplenium nidus L., Saintpaulia ionantha H. and Cyclamen persicum Mill. showed no symptoms, and no nematodes were re-isolated from the inoculation sites. Carbofuran, Phenamiphos and DCIP had better control effect compared to 5 other commonly used nematicide tested, and also showed the least phytotoxicity to orchids.