title: Fitness is Recovered with the Decline of Dimethachlon Resistance in Laboratory-induced Mutants of Sclerotinia sclerotiorum after Long-term Cold Storage.
abstract: After four years of cold storage, dimethachlon resistance of two laboratory-induced resistant Sclerotinia sclerotiorum isolates SCG7 and LA50 declined by 99.5% and 98.9%, respectively, and cross resistance to iprodione and procymidone also declined dramatically. Along with the decline of fungicide resistance, osmotic sensitivity to sodium chloride and glucose decreased tremendously; mycelial growth rate, sclerotia number and weight per potato dextrose agar (PDA) plate increased on average by 118.6%, 85. 5% and 64.5%, respectively; and virulence to detached leaves of oilseed rape increased by 72.7% on average. Significant negative correlations were detected between dimethachlon resistance levels and mycelial growth rate on PDA (r = -0.980, P = 0.021), and between resistance levels and lesion diameters on detached leaves of oilseed rape plants (r = -0.997, P = 0.002). These results have profound implications for assessing the potential risk for resistance development to dicarboximide fungicides in S. sclerotiorum.
authors.affiliation: College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Jin-Li
authors.initials: JL
authors.lastname: Li
authors.affiliation: Agro-Biotechnology Institute of Jilin Academy of Agricultural Sciences, Changchun 130033, China.
authors.forename: Feng-Ci
authors.initials: FC
authors.lastname: Wu
authors.affiliation: College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Fu-Xing
authors.initials: FX
authors.lastname: Zhu
keywords: Sclerotinia sclerotiorum; cold storage; dimethachlon resistance; fitness penalty