title: Environmental Conditions Affect Botrytis cinerea Infection of Mature Grape Berries More Than the Strain or Transposon Genotype.
abstract: Effects of environment, Botrytis cinerea strain, and their interaction on the infection of mature grape berries were investigated. The combined effect of temperature (T) of 15, 20, 25, and 30°C and relative humidity (RH) of 65, 80, 90, and 100% was studied by inoculating berries with mycelium plugs. Regardless of the T, no disease occurred at 65% RH, and both disease incidence and severity increased with increasing RH. The combined effect of T (5 to 30°C) and wetness duration (WD) of 3, 6, 12, 24, and 36 h was studied by inoculating berries with conidia. At WD of 36 h, disease incidence was approximately 75% of affected berries at 20 or 25°C, 50% at 15°C, and 30 to 20% at 30 and 10°C; no infection occurred at 5°C. Under favorable conditions (100% RH or 36 h of WD) and unfavorable conditions (65% RH or 3 h of WD), berry wounding did not significantly affect disease incidence; under moderately favorable conditions (80% RH or 6 to 12 h of WD), disease incidence was approximately 1.5 to 5 times higher in wounded than in intact berries. Our data collectively showed that (i) T and RH or WD were more important than strain for mature berry infection by either mycelium or conidia and (ii) the effect of the environment on the different strains was similar. Two equations were developed describing the combined effect of T and RH, or T and WD, on disease incidence following inoculation by mycelium (R2=0.99) or conidia (R2=0.96), respectively. These equations may be useful in the development of models used to predict and control Botrytis bunch rot during berry ripening.
authors.affiliation: First and fourth authors: Istituto di Entomologia e Patologia Vegetale, Università Cattolica del Sacro Cuore, Via E. Parmense 84, Piacenza, I-29122, Italy; second and third authors: INRA, UMR 1065 SAVE "Santé et Agroécologie du Vignoble", ISVV, Université de Bordeaux, CS 20032, 33882 Villenave d'Ornon Cédèx, France.
authors.forename: Nicola
authors.initials: N
authors.lastname: Ciliberti
authors.affiliation: First and fourth authors: Istituto di Entomologia e Patologia Vegetale, Università Cattolica del Sacro Cuore, Via E. Parmense 84, Piacenza, I-29122, Italy; second and third authors: INRA, UMR 1065 SAVE "Santé et Agroécologie du Vignoble", ISVV, Université de Bordeaux, CS 20032, 33882 Villenave d'Ornon Cédèx, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Fermaud
authors.affiliation: First and fourth authors: Istituto di Entomologia e Patologia Vegetale, Università Cattolica del Sacro Cuore, Via E. Parmense 84, Piacenza, I-29122, Italy; second and third authors: INRA, UMR 1065 SAVE "Santé et Agroécologie du Vignoble", ISVV, Université de Bordeaux, CS 20032, 33882 Villenave d'Ornon Cédèx, France.
authors.forename: Jean
authors.initials: J
authors.lastname: Roudet
authors.affiliation: First and fourth authors: Istituto di Entomologia e Patologia Vegetale, Università Cattolica del Sacro Cuore, Via E. Parmense 84, Piacenza, I-29122, Italy; second and third authors: INRA, UMR 1065 SAVE "Santé et Agroécologie du Vignoble", ISVV, Université de Bordeaux, CS 20032, 33882 Villenave d'Ornon Cédèx, France.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Rossi
mesh_terms: D020171:Botrytis / Q000235:genetics / Q000502:physiology*; D004777:Environment; D005638:Fruit / Q000254:growth & development / Q000382:microbiology / Q000502:physiology; D005838:Genotype; D008962:Models, Theoretical; D016254:Mutagenesis, Insertional; D025282:Mycelium; D010935:Plant Diseases / Q000382:microbiology / Q000517:prevention & control*; D013045:Species Specificity; D013172:Spores, Fungal; D013696:Temperature; D027843:Vitis / Q000254:growth & development / Q000382:microbiology / Q000502:physiology*
keywords: Vitis vinifera; gray mold