EARLY PHASES OF INFECTION OF ASCOCHYTA ON FABA BEANS
R SLADIC1, S SAVOCCHIA1, P KOLESIK2, SR RAO3, J DEMAJNIK1, ES SCOTT1, MD RAMSEY4 and PJ MURPHY1
1Department of Crop Protection, and 2Department of Horticulture, Viticulture and Oenology, University of Adelaide, Waite Campus, Glen Osmond, South Australia 5064, Australia; 3Department of Biotechnology, CGO Complex, Lodhi Road, New Delhi 110003, India; 4South Australian Research and Development Institute (SARDI), GPO Box 397, Adelaide 5001, South Australia, Australia
Background and objectives
Results and conclusions
To study the early stages of infection, we compared infection of faba bean leaves by A. fabae with that by A. lentis. Examination by light microscopy and laser confocal microscopy indicates that when A. lentis is applied to leaves of faba bean, there is hyphal growth and development of appressoria but no direct penetration via infection pegs or through stomata . However, when A. lentis spores are applied in conjunction with spore germination fluid from A. fabae, infection occurs. This infection develops at a slower rate than when faba bean leaves are infected with A. fabae, and pycnidia do not develop. The induced infection appears not to be related to the resistance mechanism operating in Ascot, since the infection factor (IF) induces infection by A. lentis equally well on Icarus and Ascot. The infection factor in spore germination fluid is currently being characterized.