Induction of systemic resistance against damping-off and root-rot of white lupine (Lupinus albus L.) using some bioagents, chemical inducers and a mycorrhizal fungus

Damping-off and root-rot diseases of lupine are considered the main problem in lupine production in Egypt. In this study, the effect of two bioagents i.e., Trichoderma harzianum and Bacillus megaterium, two chemical inducers i.e., salicylic and citric acid, and mycorrhizal fungus compared to the fungicide Topsin-M۷۰ were tested in vitro, greenhouse and field conditions against Fusarium exysporium, F. Solani, and Rhizoctonia solani are the causes of root rot and damping-off of lupine plants. All of the tests were done in vitro. The tested linear growth of bacteria was significantly slowed by bioagents of the three pathogenic fungi, B. megaterium. The most significant reduction was induced by T. harzianum, which was followed by T. harzianum. Sowing lupine in the seeds soil artificially inoculated with any of the three pathogenic fungi with a large increase in fresh and dry weight. The incidence of pre-and post-emergence damping-off was significantly reduced compared to the control treatment. B.megaterium and Topsin-M۷۰ exhibited the highest percentages of survived plants. In general, in all the tested bio-agents, chemical inducers, the mycorrhizal fungus, and Topsin-M۷۰ under field circumstances, the incidence of damping-off was dramatically reduced. The data obtained revealed all the tested treatments. Peroxidase, polyphenol oxidase, and chitinase enzymes, which play critical roles in plant metabolism, saw a significant increase inactivity, defense mechanisms that work against pathogens infection.

Keywords:

Bioagents , Chemical inducers , Lupine , Mycorrhizal fungi , Plant defence-related enzymes , Topsin-M۷۰