title: Inoculum production and long-term conservation methods for cucurbits and tomato powdery mildews.
abstract: The behaviour of cucurbit powdery mildews (Podosphaera xanthii and Golovinomyces cichoracearum) and tomato powdery mildew (Oidium neolycopersici) infesting detached cotyledons of Lagenaria leucantha cv. 'Minibottle' was studied in order to develop an easy culture method for pure inoculum production. High spore production was found with a combination of mannitol (0.1 m), sucrose (0.02 m) and agar (8 gl(-1)) in the cotyledon survival medium. Sporulation on cotyledons and viability of conidia were affected by the age of culture for the three species of powdery mildew tested. The age of cotyledons had also an impact of the spore production. This method was used to produce large amounts of inoculum for P. xanthii, G. cichoracearum and O. neolycopersici and enable the development of other species of powdery mildew like Leveillula taurica. Freezing conidia in liquid nitrogen enabled the long-term conservation of P. xanthii without any loss of virulence. The same method was unsuccessful with G. cichoracearum, and L. taurica and partly successful with O. neolycopersici.
authors.affiliation: INRA, Pathologie Végétale, Centre de Recherches d'Avignon, 84140 Montfavet, France. marc.bardin@avignon.inra.fr
authors.forename: Marc
authors.initials: M
authors.lastname: Bardin
authors.forename: Muna E
authors.initials: ME
authors.lastname: Suliman
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Sage-Palloix
authors.forename: Youssif F
authors.initials: YF
authors.lastname: Mohamed
authors.forename: Philippe C
authors.initials: PC
authors.lastname: Nicot
mesh_terms: D000362:Agar; D000383:Agriculture / Q000379:methods; D001203:Ascomycota / Q000502:physiology*; D018548:Cotyledon / Q000254:growth & development / Q000382:microbiology; D015925:Cryopreservation; D019662:Cucurbitaceae / Q000382:microbiology*; D003470:Culture Media; D018551:Solanum lycopersicum / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology; D013172:Spores, Fungal / Q000254:growth & development; D013997:Time Factors
chemical_list: D003470:Culture Media; D000362:Agar