Magnaporthe or Pyricularia? (by Ning Zhang, 2
May 2012)
At
the 2011 Melbourne International Botanical Congress, One Scientific Name for One Fungus was voted for. According to the new Article 59, all
legitimate fungal names are now treated equally
for the purposes of establishing priority,
regardless of the life history state of the type (The Melbourne Code should be
out in the summer of 2012).
The
end of dual nomenclature for fungi will have major impact on pleomorphic
species. For Magnaporthaceae, an
important question that has to be addressed is which genus name should be used for the
rice blast fungus. The rice blast fungus has Magnaporthe sexual state (teleomorph)
and Pyricularia asexual state
(anamorph).
At the Amsterdam CBS “One
Fungus, Which Name” symposium, the Sordariomycetes Taxonomy Discussion Group
agreed that the following criteria should be considered when choosing between
two generic name options:
·
Monophyly,
phylogeny
·
Names in use in
plant pathology, industry, etc.
·
Quarantine
issues;
·
What morphology
is most commonly encountered;
·
Stability;
·
Taxonomic
clarity; genus name should be well defined;
·
Number of needed
combinations/name changes
etc, etc.
A recently published 6-gene
phylogeny (see figure attached) with selected taxa in the Magnaporthaceae
indicates that
the current concept of both Magnaporthe and Gaeumannomyces are
polyphyletic. Magnaporthe salvinii is the type species of Magnaporthe.
Pyricularia grisea and P. oryzae are older names than M.
grisea and M. oryzae (please see the list for details on date and
type information). However, to
minimize the name change for important pathogens and quarantine issues, we
should consider conserving the Magnaporthe genus name for the rice blast
fungus (Magnaporthe oryzae).
An option is to segregate Magnaporthe from Pyricularia and limit the usage of Magnaporthe only for the clade including M. oryzae and M. grisea.
Alternatively, we will keep Magnaporthe for M. salvinii and use Pyricularia
as the genus name for the rice blast fungus.
Other options?
Please
feel free to post your comment/suggestion in this blog, which is created for
Magnaporthaceae scientific community discussion purposes. If you want to
post your phylogeny or other information here, please send to me (zhang@aesop.rutgers.edu).
