FIRST REPORT OF COLLETOTRICHUM AENIGMA AND C. SIAMENSE, THE CAUSAL AGENT OF ANTHRACNOSE DISEASE OF DRAGON FRUIT IN THAILAND

Abstract

Anthracnose disease of dragon fruit (Hylocereus undatus) is widespread in the orchards of the central region of Thailand, where it causes enormous crop losses. Colletotrichum gloeosporioides (Palmateer et al., 2007) and C. truncatum (Guo et al., 2014) were reported as the causal agent of anthracnose disease in dragon fruit. However, in Thailand, both C. capsici and C coccodes were reported to be associated with dragon fruit (USDA, 2011). In a 2012 disease survey carried out in this country, 35 isolates of Colletotrichum spp. were recovered from lesions on both stems and fruits of H. undatus in Pathum Thani, Nakhon Pathom and Samut Sakhon. In pathogenicity tests, eight isolates of Colletotrichum spp. caused necrotic lesions on the mature stems and the fruits of dragon fruit plants. Colletotrichum spp., isolates R003 (LC052316), R007 (LC052317), R020 (LC052320) and BP033 (LC052313) were identified as C. siamense (GenBank accession Nos JX010257, JX010256, AY266391.1, JX010256), respectively. Isolate R024 was identified as C. truncatum (LC052321) (GenBank accession No. KF800474.1). Isolate R009 (LC052318) and i K034 (LC052322) were identified as C. aenigma (GenBank accession Nos JX258676.1 and KJ957791.1), respectively and isolate R017 (LC052319) was identified as C. gloeosporioides (GenBank accession No. GU066652.1), based on morphological (Bailey and Jeger, 1992) and molecular characteristics (White et al., 1990). To the best of our knowledge, this is the first report of C. aenigma and C. siamense, as the agent of anthracnose disease in dragon fruit in Thailand.