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''Phoma clematidina'' is a fungal plant pathogen and the most common cause of the disease clematis wilt affecting large-flowered varieties of ''Clematis''. Symptoms of infection include leaf spotting, wilting of leaves, stems or the whole plant and internal blackening of the stem, often at soil level.〔van de Graaf P. (1999) ''Biology and Control of Phoma clematidina, causal Agent of Clematis Wilt''. PhD thesis, University of Derby, Derby, UK.〕〔(【引用サイトリンク】 van de Graaf P. (1999) Biology and control of clematis wilt. Final project report. Horticultural Development Council, UK. )〕 Infected plants growing in containers may also develop root rot.〔(van de Graaf P., Joseph M.E., Chartier-Hollis J.M. and O’Neill T.M. (1998) Root infection of cultivated clematis by ''Phoma clematidina'', causal agent of clematis wilt. In: ''Proceedings 7th International Congress of Plant Pathology'', 1998. Edinburgh, UK: BSPP/ISPP, 3, 3·7·67 )〕 ==Taxonomy== The asexual stage (anamorph) of the fungus was first described by the German botanist and mycologist Felix von Thümen in 1880 as ''Ascochyta clematidina''. Based on new scientific insights into the differences in spore formation between species,〔Boerema G.H. and Bollen G.J. (1975) Conidiogenesis and conidial septation as differentiating criteria between ''Phoma'' and ''Ascochyta''. ''Persoonia'', 8, 111-144.〕 it was reclassified as ''Phoma clematidina'' by the Dutch mycologist Gerhard Boerema in 1978.〔 Genetic sequencing has suggested that ''Phoma clematidina'' is heterothallic which means that two compatible strains (mating types) of the fungus would need to come together under the right environmental conditions to produce a sexual stage (teleomorph).〔 (Woudenberg J.H.C., de Gruyter J., Crous P.W. and Zwiers, L.-H. (2011) Analysis of the mating-type loci of co-occurring and phylogenetically related species of ''Ascochyta'' and ''Phoma''. ''Molecular Plant Pathology'', 13(4): 350-362. ) 〕 Both mating types of ''Phoma clematidina'' are known to occur in Europe, and yet no sexual stage (which is most likely to be a ''Didymella'' species) has ever been described. 〔〔 Molecular phylogenetic analyses have revealed that some fungal isolates recovered from wild ''Clematis'' species, previously identified as ''Phoma clematidina'', are in fact two closely related species of ''Phoma'' and ''Ascochyta'' with the sexual stages ''Didymella vitalbina'' and ''Didymella clematidis'' respectively.〔 The latter fungus has been successfully used as a biological control agent of ''Clematis vitalba'', which is seen as an invasive plant in New Zealand.〔(【引用サイトリンク】 Gourlay A.H., Wittenberg R., Hill R.L., Spiers A.G., and Fowler S.V. (2000) The biological control programme against ''Clematis vitalba'' in New Zealand. In: Spencer N.R. (ed), ''Proceeding of the 10th International Symposium on Biological Control of Weeds'': 709–718. Montana State University, Bozeman, MT, USA )〕〔(Paynter Q., Waipara N., Peterson P., Hona S., Fowler S., Gianotti A. and Wilkie P. (2006) The impact of two introduced biocontrol agents, ''Phytomyza vitalbae'' and ''Phoma clematidina'', on ''Clematis vitalba'' in New Zealand. ''Biological Control'', 36: 350-357. )〕 Unlike ''Phoma clematidina'', the two closely related ''Didymella'' species (and their anamorphs) have not been found on large-flowered ''Clematis'' varieties.〔 The previous misidentification of these species means that some literature, particularly that on the biological control of ''C. vitalba'', referring to ''Phoma clematidina'' is actually describing work on ''Didymella clematidis'' and its ''Ascochyta'' anamorph.〔〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Phoma clematidina」の詳細全文を読む スポンサード リンク
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