PAG-I Plant Genome I Conference

Town & Country Conference Center, San Diego, CA, November, 1992.


PG-I: 45pg1

GENETIC ANALYSIS OF A SINGLE UREDINIOSPORE DERIVED CULTURE OF CRONARTIUM QUERCUUM F. SP. FUSIFORME, USING RAPD MARKERS.

R. L. Doudrick, C. D. Nelson, and W. L. Nance. U. S. D. A. Forest Service, Southern Forest Experiment Station, Forestry Sciences Laboratory, Gulfport, MS.


Random amplified polymorphic-DNA (RAPD) markers were developed for Cronartium quercuum f. sp. fusiforme, the causal agent of fusiforme rust disease on southern pines. Genetic linkages were identified between 103 RAPD marker loci in a segregating population of 48 gametothalli and drops of spermatia produced from a single urediniospore derived culture. A preliminary genetic linkage map with eight linkage groups and 12 linked pairs is presented. Based on the extent of linkage detected among the loci identified, the size of the nuclear genome of C.q. fusiforme is estimated to be approximately 5100 recombination units (centiMorgans, cM). The 103 loci characterized provide approximately 40% coverage of the genome at 25 cM separation between loci. The RAPD marker loci may be of immediate utility in fingerprint identification of laboratory cultures and field isolates for epidemiological studies. Even this preliminary genetic linkage map has great potential for aiding in studies on host:pathogen interactions in fusiform rust disease and monitoring variation in pathogen populations.


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