A combined morphological and molecular approach to characterize isolates of arbuscular mycorrhizal fungi in Gigaspora (Glomales)

Citation
L. Lanfranco et al., A combined morphological and molecular approach to characterize isolates of arbuscular mycorrhizal fungi in Gigaspora (Glomales), NEW PHYTOL, 152(1), 2001, pp. 169-179
Citations number
41
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences
Journal title
NEW PHYTOLOGIST
ISSN journal
0028-646X → ACNP
Volume
152
Issue
1
Year of publication
2001
Pages
169 - 179
Database
ISI
SICI code
0028-646X(200110)152:1<169:ACMAMA>2.0.ZU;2-J
Abstract
Morphological features of resting spores and information from nucleotide se quences of ribosomal RNA were used to characterize seven mycorrhizal fungal isolates in Gigaspora from different geographical areas. Detailed observations were made under the light microscope on single spores mounted in Melzer's reagent and polyvinyl alcohol-lactic acid-glycerol med ium to resolve size, colour and cell wall structures. Neighbour-joining ana lyses were carried out on a portion of the 18S gene and on the internal tra nscribed spacer (ITS) region amplified by PCR from multisporal DNA preparat ions. Combined data allowed us to design oligonucleotides that unambiguously dist inguished Gi. rosea from Gi. margarita and Gi. gigantea and also identified two isolates as Gi. rosea that had been previously diagnosed as Gi. margar ita. ITS sequences revealed substantial genetic variability within clones o f a single isolate of Gi. rosea as well as among geographically disjunct Gi . rosea isolates. The results show how complementary morphological and molecular data can cla rify relationships among species of low morphological divergence. Sequence information allowed the extent of genetic divergence within these species t o be investigated and provided useful PCR primers for detection and identif ication.