Various morphological and genetic characteristics were compared among six isolates ofColletotrichum from maize and six from sorghum. For the first time, a teleomorph was induced in sorghum isolates by pairing them on autoclaved sorghum leaves in a humidity chamber. The sorghum teleomorph was morphologically similar toGlomerella graminicola andGlomerella tucumanensis, the teleomorphs ofColletotrichum isolates from maize and from sugarcane, respectively. Mating tests demonstrated thatGlomerella isolates from maize and sorghum were not interfertile. Several small but consistent differences in the morphologies of the isolates from maize and from sorghum were observed which agreed with earlier reports. DNA fingerprints detected as restriction fragment length polymorphisms of mitochondrial DNA and random polymorphic DNA (RAPD) produced from nuclear DNA by the polymerase chain reaction could be used to reliably and unambiguously distinguish members of the two groups of isolates. Results of a statistical analysis of similarity of the RAPD fingerprints suggested that maize and sorghum isolates ofColletotrichum are only about 45% similar (±10%) and represent two distinct and separate genetic lineages. We conclude that isolates ofColletotrichum from maize and sorghum are sibling species since they are morphologically very similar but reproductively completely isolated.
|Number of pages||11|
|State||Published - Sep 1992|
Bibliographical noteFunding Information:
We are grateful to Dr. Walter de Milliano, Dr. H. P. da Silva, Dr. Kabore Blaise, Dr. Richard Frederick-sen, and Dr. Ralph Nicholson for generously providing the fungal isolates used in this study. We thank Dr. John Axtell for the gift of seeds of the sorghum cultivar IS8361. We appreciate the help we received from Dr. Morris Levy and Dr. Shizhong Xu in preparing the relatedness dendrogram. We especially thank Mr. Howard Laffoon for excellent technical assistance. This research was supported by Grants 88-37263-3923 and 90-37262-5445 from the CRGO of the USDA to R.M.H. This is Journal Paper No. 13,307 from the Purdue University Agriculture Experiment Station.
- Colletotrichum graminicola
- DNA fingerprinting
- cluster analysis
- filamentous fungi
- genetic diversity
ASJC Scopus subject areas
- Applied Microbiology and Biotechnology