An Aphelenchoides sp. nematode Parasitic of Polianthes tuberosa in the Mekong Delta.
Polianthes tuberosa is a commercially valuable flower crop in the Mekong Delta of Vietnam that is propagated by the harvesting and planting of bulbs. The cultivation of P. tuberosa is complicated by an endemic nematode infection that damages a high proportion of the plants. Based on morphological criteria and ribosomal RNA gene sequencing, we have determined that the infection is caused by an Aphelenchoides sp. nematode and is most likely Aphelenchoides besseyi. By scoring various parts of harvested plants with flowers for the presence of viable nematodes over a period of six months, we determined that the nematode is an ectoparasite that can survive the intercrop periods, especially in the bulbs that are used to plant new crops. A comparison of farming practices in the Mekong Delta failed to identify useful control methods, but rather indicated that fields that have cultivated P. tuberosa for the longest periods suffer the worst damage from the nematode infection. Finally, we demonstrated that the nematode is capable of infecting 30 rice cultivars but does not cause the white tip disease usually associated with A. besseyi infection.
Thi Thu Cuc
Nguyen
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Cantho University, College of Agriculture and Applied Biology, Department of Plant Protection, 3/2 street, Can Tho City, Vietnam Department of Cell and Molecular Biology, Göteborg University, S-405 30 Göteborg, Sweden.
Pilon
Marc
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