The effects of infection of Botryosphaeria berengriana f.sp. piricola on cell membrane permeability and defendant enzymes in different resistance cultivars of apple
Abstract:At several stages after inoculated by Botryosphaeria berengriana f.sp. piricola., three cultivars of apple, with different levels of resistance to apple ring rot disease on stem, were analysed for the cell membrane permeability and activities of defendant enzymes. Within 38 days after inoculation, the change of electrolyte leakage rate (ELR) of three apple cultivars showed similar trend, increased at first and followed by a decrease. The maximum changes of ELR of Jiguan, Ralls and Fuji reached 8.1%, 12.2% and 18.4% respectively. The change was lower in resistant cultivar (Jiguan) than in susceptible cultivars (Fuji and Ralls). The change of phenylanine ammonialyase (PAL), superoxide dismutase (SOD), peroxidase (POD) and polyphenoloxidase (PPO) in three apple cultivars showed the induced peaks following the inoculation and the peak of resistant cultivar (Jiguan) appeared later than susceptible cultivars (Ralls and Fuji). The maximum changes of PAL, SOD and POD of Jiguan reached 234, 50.88 U·g-1FW·h-1 and 14.22 U·g-1FW·min-1 respectively and were higher than those of Ralls and Fuji. The maximum change of PPO of Jiguan was 37.78 U·g-1 FW·min-1, lower than those of Ralls and Fuji.