Survey of Phaeomoniella chlamydospora in vineyard weeds

ABSTRACT Petri disease is serious, complex and difficult to control in vines worldwide. The main causal agent of this disease is the fungus Phaeomoniella chlamydospora. This fungus also occurs in the vineyard weed Convolvulus arvensis. In Brazil, this fungus was found only in grapevines. Thus, the aim of the present study was to carry out a phytosociological survey of weeds in an area with different vine rootstocks, as well as in a field of seedlings production, in an experimental area with vines and in different areas with commercial vineyards, besides verifying which weed species could be hosting the fungus P. chlamydospora. For the phytosociological survey of weeds, a square was randomly cast ten times at the site, followed by counting, identification and sampling of all species. To verify host species of the fungus, vascular tissue of plants was isolated in culture media and DNA extraction from the same plant tissue was carried out followed by PCR with specific primers of the fungus for the elongation factor gene (Pchlamy-EF-F 5’-CTCATTATCACATTTTGCTGC-3’ and Pchlamy-EF-R 5’-GAGAACAGTCAGTGATGAGC-3’). Considering all surveyed fields, 46 weed species were detected in 17 families, especially Asteraceae and Poaceae, which had the largest number of species. Using conventional or molecular methods, the fungus P. chlamydospora was not detected infecting weeds, which highlights that Petri disease occurs only in grapevines.

摘要 佩特里病害（Petri disease）在全球葡萄种植园中危害严重、情况复杂且难以防控。该病害的主要致病菌为真菌隐壳层卧孔菌（Phaeomoniella chlamydospora），该真菌亦存在于葡萄园杂草田旋花（Convolvulus arvensis）中。在巴西，该真菌仅在葡萄植株中被检出。因此，本研究旨在对不同葡萄砧木种植区、育苗大田、葡萄试验种植区以及商业葡萄园开展杂草植物社会学调查，并验证哪些杂草物种可作为该真菌P. chlamydospora的寄主。在杂草植物社会学调查中，研究人员在各调查区域随机布设10个样方，随后对所有杂草物种进行计数、鉴定并采集样本。为验证该真菌的寄主物种，研究人员从植物维管组织中分离该真菌的培养物，并从同一植物组织中提取DNA，采用针对该真菌延伸因子基因的特异性引物（Pchlamy-EF-F 5’-CTCATTATCACATTTTGCTGC-3’ 与 Pchlamy-EF-R 5’-GAGAACAGTCAGTGATGAGC-3’）进行PCR扩增。综合所有调查地块，共在17个科中检出46种杂草，其中菊科（Asteraceae）与禾本科（Poaceae）的物种数量最多。无论是采用传统培养方法还是分子检测方法，均未检出P. chlamydospora侵染杂草，这表明佩特里病害仅发生于葡萄植株中。