title: [Effects of silicon supply and Sphaerotheca fuliginea inoculation on resistance of cucumber seedlings against powdery mildew].
abstract: By the method of hydroponic culture, this paper studied the effects of soluble silicon (Si) supply and Sphaerotheca fuliginea inoculation on the active oxygen metabolism, SiO2 content and disease resistance of a susceptible cultivar. The results showed that the O2*- producing rate and H2O2 and MDA contents of cucumber leaf were increased by Sphaerotheca fuliginea inoculation, but reduced by the inoculation plus Si supply. The inoculation enhanced the catalase (CAT) and peroxidase (POD) activities in plant leaves but decreased their superoxide dismutase (SOD) activity, while inoculation plus Si supply increased the activities of these enzymes. Inoculation increased the scorbate (AsA) and glutathione (GSH) contents in plant leaves. The AsA content in Si-supplied plant leaves was lower than that of Si-deprived ones, whereas the GSH content was in reverse. Whether inoculated or not, the SiO2 content in Si-supplied plant leaves was significantly higher than that of Si-deprived ones. The disease index was significantly decreased by Si-supply.
authors.affiliation: State Agriculture Ministry Laboratory of Horticultural Plant Growth Development and Biotechnology, Department of Horticulture, Zhejiang University, Hangzhou 310029, China. veg-phy@zju.edu.cn
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Wei
authors.forename: Zhujun
authors.initials: Z
authors.lastname: Zhu
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.forename: Qiuju
authors.initials: Q
authors.lastname: Yao
mesh_terms: D001203:Ascomycota / Q000187:drug effects / Q000254:growth & development; D018553:Cucumis sativus / Q000378:metabolism / Q000382:microbiology*; D005659:Fungicides, Industrial / Q000494:pharmacology*; D010935:Plant Diseases / Q000382:microbiology*; D036226:Seedlings / Q000378:metabolism / Q000382:microbiology*; D012825:Silicon / Q000494:pharmacology*
chemical_list: D005659:Fungicides, Industrial; D012825:Silicon