Restriction fragment length polymorphisms of the mitochondrial DNA of Phytophthora megasperma isolated from soybean, alfalfa, and fruit trees

1989 ◽  
Vol 67 (2) ◽  
pp. 529-537 ◽  
Author(s):  
Helga Förster ◽  
T. G. Kinscherf ◽  
S. A. Leong ◽  
Douglas P. Maxwell
Keyword(s):  
High Temperature ◽  
Restriction Fragment ◽  
Fragment Length ◽  
Phylogenetic Analyses ◽  
Fruit Trees ◽  
Biological Species ◽  
Polymorphism Analysis ◽  
Phytophthora Megasperma ◽  
Restriction Patterns ◽  
Restriction Fragment Length

The mtDNAs from 24 small oogonial soybean-specific Phytophthora megasperma f.sp. glycinea (Pmg) isolates, 10 small oogonial alfalfa-specific P. megasperma f.sp. medicaginis (Pmm) isolates, 2 small oogonial nonhost-specific P. megasperma isolates from apple, 6 large oogonial nonhost-specific P. megasperma isolates from alfalfa or cherry, and 1 high-temperature P. megasperma isolate from alfalfa were investigated by restriction fragment length polymorphism analysis. Restriction patterns of the mtDNAs obtained by digestion with six restriction endonucleases showed limited variation within isolates of Pmg and Pmm. However, restriction patterns of Pmg and Pmm mtDNAs were very different. All nonhost-specific isolates of P. megasperma and the high-temperature isolate had restriction patterns that differed from each other and from those of Pmg and Pmm. The restriction patterns of the nuclear DNAs also distinguished these isolates from Pmg and Pmm. Phylogenetic analyses indicate that Pmg and Pmm are genetically distinct subgroups that represent biological species of P. megasperma and that several additional subgroups, possibly biological species, are present in the P. megasperma complex.

Restriction fragment length polymorphisms demonstrate single origin of infection centers in Phellinus weirii

1994 ◽  
Vol 72 (4) ◽  
pp. 440-447 ◽  
Author(s):  
Hanhong Bae ◽  
Everett M. Hansen ◽  
Steven H. Strauss
Keyword(s):  
Mitochondrial Dna ◽  
Restriction Fragment ◽  
Ribosomal Dna ◽  
Fragment Length ◽  
Host Species ◽  
Root Rot ◽  
Biological Species ◽  
Douglas Fir ◽  
Dna Probes ◽  
Restriction Fragment Length

Restriction fragment length polymorphism (RFLP) markers were used to study genetic variation in the basidiomycete fungus Phellinus weirii (Murr.) Gilbertson, the cause of laminated root rot of conifers. In an initial study, three isolates each from the Douglas-fir type and the cedar-type biological species were surveyed with 12 restriction enzymes and 20 random, mitochondrial, and nuclear-ribosomal gene probes. The two biological species were distinct with most probe–enzyme combinations (91%). Variation within biological species was detected for the random and ribosomal DNA probes but not for the mitochondrial DNA probes. In a subsequent study 65 probe–enzyme combinations (13 × 5) that had detected variation within the Douglas-fir type biological species were used to analyze 27 isolates derived from six infection centers, two host species, and two geographic areas in western Oregon. Infection centers differed from one another in numerous probe–enzyme combinations but were nearly genetically uniform within. Isolates from the two host species, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and mountain hemlock (Tsuga mertensiana (Bong.) Carr.), showed few RFLP differences. Initiation of infection centers, and subsequent vegetative or basdiospore initiated immigration, appear to be rare events. Key words: ribosomal DNA, mitochondrial DNA, RFLP, root rot, conifer.

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