S. Moricca et al., Molecular and conventional detection and identification of Cladosporium tenuissimum on two-needle pine rust aeciospores, CAN J BOTAN, 77(3), 1999, pp. 339-347
Citations number
32
Categorie Soggetti
Plant Sciences
Journal title
CANADIAN JOURNAL OF BOTANY-REVUE CANADIENNE DE BOTANIQUE
An integrated approach, based on the analysis of both molecular and morphol
ogical characters, has led to the unambiguous detection and identification
of the rust hyperparasite Cladosporium tenuissimum from aeciospores of the
two-needle pine rust fungi Cronartium flaccidum and Peridermium pini. Clado
sporium tenuissimum was first detected from contaminated field-collected ru
st spores using the polymerase chain reaction (PCR) method. The similar-siz
ed amplified DNA of the parasite was then separated from rust DNA using ele
ctrophoretic migration, reamplified separately with the nested PCR, and seq
uenced. Sequence comparison in the data banks enabled the hyperparasite to
be recognised as a species of Cladosporium. Molecular detection was followe
d by conventional identification, obtained by plating rust spores on potato
dextrose agar, a selective medium for rusts, since they are unable to grow
on such a common substrate, and isolating the hyperparasite in pure cultur
e. It was subsequently identified as C. tenuissimum. Traditional identifica
tion would not have been possible without guidance from the molecular data,
which focused attention on the mycoparasite. Macro- and micro-scopic featu
res of colonies are also given to help with future identification on spore
sources from other geographical areas and, if this should occur future iden
tification on other rusts.