title: Unexpectedly high susceptibility of micropropagated rhubarb (Rheum rhaponticum L.) to spot disease caused by Ramularia rhei.
abstract: Rapid, large-scale micropropagation of a Rheum rhaponticum (rhubarb) breeding line, selected for the absence of autumn dormancy, produces changes typical of somaclonal variation. Among these is enhanced susceptibility to foliar infection by the spot disease pathogen Ramularia rhei, with consequential increased spore production on infected leaves. This provides an increased level of inoculum in the late season, leading to commercially unacceptable petiole spotting as spores are washed from the lamina on to the petiole surface. Infection of conventionally propagated plants does not exceed market acceptability. Consequently, to maintain the commercial value of this rhubarb selection micropropagation must be avoided, at least until an acceptably modified protocol is available.
authors.affiliation: Horticultural Department, Henan Vocation-Technical Teachers College, Xinxiang, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhao
authors.forename: B W W
authors.initials: BW
authors.lastname: Grout
authors.forename: P C
authors.initials: PC
authors.lastname: Crisp
mesh_terms: D001203:Ascomycota / Q000472:pathogenicity*; D015169:Colony Count, Microbial; D004198:Disease Susceptibility / Q000276:immunology; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology; D012250:Rheum / Q000276:immunology / Q000382:microbiology*; D012621:Seasons; D013172:Spores, Fungal / Q000254:growth & development; D013696:Temperature