Pythium vexans Causing Stem Rot of Dendrobium in Yunnan Province, China

Abstract

Since 2002 a severe root and stem disease of Dendrobium has occurred periodically each year in the plantations of Simao City, Yunnan Province, China. Symptoms included water-soaked and brown lesions, and rot of tissues. Based on the morphological characteristics and the internal transcribed spacer-1, 5.8S ribosomal RNA gene, and internal transcribed spacer 2 and b-tubulin gene sequences, the pathogen was identified as Pythium vexans de Bary. The pathogenicity of the fungus was confirmed by satisfying KochÕs postulates. This is the first world record of stem rot of Dendrobium caused by P. vexans.

First Report of Dragon Fruit (Hylocereus undatus) Anthracnose Caused by Colletotrichum truncatum in China

“…After the agar surface was fully covered in one of the plates, the colony diameters of all plates were measured by the criss‐cross‐method (Tao et al. ).…”

“…Three plates were used for each temperature, and the experiment was repeated at least once. After the agar surface was fully covered in one of the plates, the colony diameters of all plates were measured by the criss-cross-method (Tao et al 2011).…”

“…The pathogen was cultured on PSA at 25°C. After 4 days, DNA was extracted and the ITS and betatubulin of the fungal genome were amplified and sequenced as described by Tao et al (2011).…”

Diversity and populations of Phytophthora, Phytopythium and Pythium species recovered from sediments in an agricultural run‐off sedimentation reservoir

“…helicoides and Pp. vexans , causing root rot and damping off on many ornamental plants (Hong & Moorman, ; Tao et al ., ; Yang et al ., ; Kageyama, ).…”

Characterization of species associated with Pythium soft rot of ginger and evaluation of Pythium Oligandrum as a biocontrol

“…(Schroeder et al, 2013), sequencing alternative genes has been deployed. These include nuclear encoded β-tubulin, SSU (small subunit) and LSU (large subunit) Kumar and Shukla, 2006;Lévesque and De Cock, 2004;Liu et al, 2012;Moralejo et al, 2008;Mu et al, 1999;Spies et al, 2011a;Tao et al, 2011), CoxI (cytochrome c oxidase subunit 1) (Kroon et al, 2004;Robideau et al, 2011), CoxII (Garzón et al, 2005b;Kageyama et al, 2005;Kammarnjesadakul et al, 2011;Martin, 2000;Nechwatal et al, 2005;Spies et al, 2011a;Villa et al, 2006) and NADH (dehydrogenase subunit 1) (Kroon et al, 2004;Moralejo et al, 2008).…”