K. Zeise et A. Von Tiedemann, Morphological and physiological differentiation among vegetative compatibility groups of Verticillium dahliae in relation to V-longisporum, J PHYTOPATH, 149(7-8), 2001, pp. 469-475
Citations number
28
Categorie Soggetti
Plant Sciences
Journal title
JOURNAL OF PHYTOPATHOLOGY-PHYTOPATHOLOGISCHE ZEITSCHRIFT
Twenty-four isolates of Verticillium dahliae from various geographic region
s and host origins were assigned to vegetative compatibility groups (VCG) b
ased on complementation between nitrate-non-utilizing (nit) mutants. The VC
G assignment was associated with clearly distinguishable morphological and
physiological characteristics. Most isolates of VCG 2B produced deep black
colonies, small conidia (3.62 +/- 0.02 mum), and spherical microsclerotia.
They exhibited polyphenol oxidase (PPO) activity, high sporulation rate in
shake cultures, fluorescence on sanguinarine-amended PDA (snPDA) and excret
ion of dark pigment on Czapek Dox agar. The isolates assigned to VCG 4B had
significantly longer conidia (4.73 +/- 0.04 mum), spherical microsclerotia
and white, fluffy colonies due to enhanced production of aerial mycelium.
They excreted only traces of dark pigment, exhibited PPO activity, did not
fluoresce on snPDA and had limited ability to sporulate in shake cultures.
Except for lacking PPO activity the only heterokaryon self-incompatible iso
late (HSI) was similar to VCG 4B. Ten isolates of Verticillium longisporum
from cruciferous hosts did not produce nit mutants. They had clearly longer
conidia (7.41 +/- 0.05 mum), formed elongate microsclerotia, and only poor
ly sporulated in shake cultures. They did not excrete dark pigment, lacked
PPO, and failed to fluoresce on snPDA. The results indicate a clear morphol
ogical and physiological differentiation not only between the two species V
. longisporum and V. dahliae but also among the VCGs of V. dahliae.