Leaf disease caused by Epicoccum thailandicum on Amomum villosum in China

Abstract

Amomum villosum is widely planted as a cash crop and medicinal plant. Recent reports of leaf diseases that result in yield reduction of Amomum villosum fruits raise concerns, which may play an important role in yield losses. Understanding the aetiology of current and new diseases of Amomum villosum is important to address production issues and to formulate effective disease control measures. An organizational separation method was used to isolate phytopathogen from leaves. Ten fungi were isolated from the diseased leaves. Among the selected microorganisms, fungi AP5 showed typical pathogenic symptoms and fulfilling Koch’s requirements. The rDNA internal transcribed spacer region (ITS) with primers ITS1/ITS4, 28S ribosomal RNA gene (LSU) with primers NL1/NL4, RNA polymerase II second largest subunit (RPB II) with primers fRPB2-5f/fRPB2-7cR, and beta-tubulin (tub2) with primers BT2a/BT2b of pathogenic strain were amplified and sequenced. AP5 was identified as Epicoccum thailandicum based on morphological and phylogenetic analyses. This is the first report that Epicoccum thailandicum is the pathogenic fungi infecting Amomum villosum leaves.

Keywords

• Amomum villosum
• Epicoccum thailandicum
• leaf disease
• pathogenic fungi
• phylogenetic analyses