RosaceaePrevalencePrunusFragariaPotentillaMalusSorbusSpiraeaGeumSelf-Incompatibility in Flowering PlantsPyrusErwinia amylovoraPlant Components, AerialRosaGenome, PlantRosalesPollenCross-Sectional StudiesFruitRisk FactorsPhylogenyPolyploidyFlowersRibonucleasesExpressed Sequence TagsGeneticsTriterpenesChromosomes, PlantGenes, PlantPollinationTreesGenetic Markers