| bulked segregant analysis identifies molecular markers linked to melampsora medusae resistance in populus deltoides. | abstract in the north central united states, leaf rust caused by melampsora medusae is a major disease problem on populus deltoides. in this study we identified molecular markers linked to a m. medusae resistance locus (lrd1) that was segregating 1:1 within an intraspecific p. deltoides family (c9425dd). previous field results were confirmed in the controlled environment of a growth chamber through an excised whole-leaf inoculation method. using bulked segregant analysis we identified two random ... | 2000 | 18944531 |
| fungal pathogen (mis-) identifications: a case study with dna barcodes on melampsora rusts of aspen and white poplar. | wide variation and overlap in morphological characters have led to confusion in species identification within the fungal rust genus melampsora. the melampsora species with uredinial-telial stages on white poplar and aspens are especially prone to misidentification. this group includes the melampsora populnea species complex and the highly destructive pine twisting rust, melampsora pinitorqua, which alternates between hosts in populus section populus and pinus. our objective was to compare morpho ... | 2009 | 19249365 |
| the wound-, pathogen-, and ultraviolet b-responsive myb134 gene encodes an r2r3 myb transcription factor that regulates proanthocyanidin synthesis in poplar. | in poplar (populus spp.), the major defense phenolics produced in leaves are the flavonoid-derived proanthocyanidins (pas) and the salicin-based phenolic glycosides. transcriptional activation of pa biosynthetic genes leading to pa accumulation in leaves occurs following herbivore damage and mechanical wounding as well as infection by the fungal biotroph melampsora medusae. in this study, we have identified a poplar r2r3 myb transcription factor gene, myb134, that exhibits close sequence similar ... | 2009 | 19395405 |
| the transcriptional response of hybrid poplar (populus trichocarpa x p. deltoides) to infection by melampsora medusae leaf rust involves induction of flavonoid pathway genes leading to the accumulation of proanthocyanidins. | the transcriptional response of hybrid poplar (populus trichocarpa x p. deltoides) to poplar leaf rust (melampsora medusae) infection was studied using the populus 15.5k cdna microarray. pronounced changes in the transcriptome were observed, with approximately 20% of genes on the array showing either induction or repression of transcription within the 9-day infection timecourse. a small number of pathogen-defense genes encoding pr-1, chitinases, and other pathogenesis-related proteins were consi ... | 2007 | 17601169 |
| association of mmd1, a major gene for resistance to melampsora medusae f. sp. deltoidae, with quantitative traits in poplar rust. | abstract a single gene, mmd1, which conditions resistance and a necrotic flecking response to a monouredinial isolate of melampsora medusae f. sp. deltoidae and is presumed to possess the corresponding avirulence gene, was previously shown to segregate 3:1 (resistant to susceptible) in an interspecific hybrid poplar f(2) progeny. some inoculated clones of the resistant phenotypic class of this progeny were completely resistant and bore no uredinia, but most bore some sporulating uredinia with ac ... | 1998 | 18944979 |
| genetic diversity in poplar leaf rust (melampsora medusae f. sp. deltoidae) in the zones of host sympatry and allopatry. | abstract poplar leaf rust caused by melampsora medusae f. sp. deltoidae is a widespread disease in north america, where epidemics occur within zones of sympatry and allopatry of telial hosts (populus spp.) and aecial hosts (larix spp.). to test the hypothesis that epidemics originate in the zone of sympatry where the rust can complete its life cycle, populations in sympatry and allopatry were analyzed with single-strand conformational polymorphism for codominant detection of alleles directly fro ... | 2007 | 18943580 |