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Arbutus menziesii leaf spot
Byrain,
24-12-2013 23:44
Conidia hyaline & mostly uniseptate.
Conidia range = (21) 22 - 29 (30) x 5.5 - 7 µm
Average conidium = 25.45 x 6.03 µ
Q range = 3.5 - 5.09
Average Q = 4.24
20 conidia measured in H2O.
I'm having difficulty finding literature concerning these leaf spots on Arbutus menziesii, any ideas are appreciated.
More macro images can be seen here - http://mushroomobserver.org/156251?q=1higi
Byrain,
25-12-2013 00:32
Re : Arbutus menziesii leaf spot
Westcott's Plant Disease Handbook lists a few possible names:
Ascochyta hanseni - With brownish & smaller conidia? http://bit.ly/1e9Gwi0
Cryptostictis arbuti (= Seimatosporium arbuti) - 4-septate conidia? http://bit.ly/1bp5Htv
Didymosporium arbuticola - ???
Mycosphaerella arbuticola - Different macro & conidia. http://bit.ly/19d2ttp
Phyllosticta fimbriata - Far smaller conidia. http://bit.ly/K1cFP6
I also found out about Diplodia maculata, I'm not sure about this one from the short latin description I found... http://bit.ly/JbPsd3
Any others or corrections? :)
Ascochyta hanseni - With brownish & smaller conidia? http://bit.ly/1e9Gwi0
Cryptostictis arbuti (= Seimatosporium arbuti) - 4-septate conidia? http://bit.ly/1bp5Htv
Didymosporium arbuticola - ???
Mycosphaerella arbuticola - Different macro & conidia. http://bit.ly/19d2ttp
Phyllosticta fimbriata - Far smaller conidia. http://bit.ly/K1cFP6
I also found out about Diplodia maculata, I'm not sure about this one from the short latin description I found... http://bit.ly/JbPsd3
Any others or corrections? :)
Byrain,
25-12-2013 21:36
Re : Arbutus menziesii leaf spot
I looked in 'Microfungi on Land Plants' and could find nothing on Arbutus...
Any other texts I can try to find?
Any other texts I can try to find?
Byrain,
25-12-2013 22:33
Re : Arbutus menziesii leaf spot
Could this be Septoria unedonis known from Arbutus unedo? I'm not sure the description (Desmazières, J.B.H.J. 1847. Quatorzième notice sur les plantes cryptogames récemment découvertes en France. 8:9-37) is online? Most Septoria conidia images on google look a bit different though...
Guy Garcia,
26-12-2013 12:07
Re : Arbutus menziesii leaf spot
Byrain,
26-12-2013 18:50
Re : Arbutus menziesii leaf spot
Hi Guy,
Thanks for the link. My understanding of the description is shakey at best with google translate, but it doesn't seem include much about the spores exluding length which may be a bit long...
Thanks for the link. My understanding of the description is shakey at best with google translate, but it doesn't seem include much about the spores exluding length which may be a bit long...
Byrain,
26-12-2013 20:20
Re : Arbutus menziesii leaf spot
'Westcott's Plant Disease Handbook' says this about Didymosporium, "Conidia are slime-spores in acervuli; dark, two-celled." I also translated the Diplodia maculata description I pasted a link to earlier to learn it should have brown conidia which is corroborated by this...
http://website.nbm-mnb.ca/mycologywebpages/Moulds/Diplodia.html
And this paper says this about Septoria, "Most taxonomists adopted a generic concept of Septoria that included fungi forming pycnidial conidiomata with holoblastic, hyaline, smooth-walled conidiogenous cells with sympodial and/or percurrent proliferation and hyaline, smooth, filiform to cylindrical multi-septate conidia (Sutton 1980, Constantinescu 1984, Sutton & Pascoe 1987, 1989, Farr 1991, 1992)."
http://studiesinmycology.org/content/75/1/213.full
I think I'm going in circles, perhaps this is undescribed? But what genus? Family?
http://website.nbm-mnb.ca/mycologywebpages/Moulds/Diplodia.html
And this paper says this about Septoria, "Most taxonomists adopted a generic concept of Septoria that included fungi forming pycnidial conidiomata with holoblastic, hyaline, smooth-walled conidiogenous cells with sympodial and/or percurrent proliferation and hyaline, smooth, filiform to cylindrical multi-septate conidia (Sutton 1980, Constantinescu 1984, Sutton & Pascoe 1987, 1989, Farr 1991, 1992)."
http://studiesinmycology.org/content/75/1/213.full
I think I'm going in circles, perhaps this is undescribed? But what genus? Family?
Byrain,
05-01-2014 20:05
Re : Arbutus menziesii leaf spot
Bump, any idea on genus, family, or anything more specific than fungi? :)