Induction of Systemic Resistance in Cucumber by Plant Growth-Promoting Rhizobacteria: Duration of Protection and Effect of Host Resistance on Protection and Root Colonization

摘要: Two plant growth-promoting rhizobacteria, Pseudomonas putida strain 89B-27 and Serratia marcescens 90-166, which previously induced systemic resistance (ISR) in cucumber 'Straight 8' against anthracnose caused by Colletotrichum orbiculare, were used to determine the duration of ISR cucumber. activity occurred at first-leaf stage, increased over time, was maintained least fifth-leaf stage. With less stable, occurring second-, fourth-, stages. Cultivar specificity colonization capacity two strains studied one resistant three susceptible cultivars under greenhouse conditions. Strain all three, whereas 90-166 cultivars. Both failed induce cultivar. Root patterns also differed. Populations declined a consistent rate dropping from log 10 8.2 CFU/g fresh weight roots 1 week after planting 3.2 4 weeks planting. In contrast, populations rapidly 7.4 2 inoculation then decreased more slowly There no relationship between on roots. while bacteria decreased.