SEMINAR: Plant Biology Research Seminar

Damping-off and root rot disease caused by Pythium spp. is the main reason for yield reduction of common bean (Phaseolus vulgaris). When Pythium disease occurs in conjunction with waterlogging, the challenge to common bean production can be critical. Current control of Pythium damping-off and root rot disease on common bean is neither effective nor economical. Host resistance offers the most effective and long-term disease management strategy for controlling this disease. My research has identified common bean varieties with resistance to P. irregulare with or without waterlogging. It highlights how waterlogging increases root and hypocotyl disease severity caused by P. irregulare. It is now possible to develop disease-waterlogging resistant bean varieties needed across environments that are challenged by both root/hypocotyl disease and periodic waterlogging. Hypocotyl disease was correlated with some seed and plant traits, such as country of origin, days to flower and seed lustre. This finding provides alternative foci for common bean breeders in developing new more disease-resistant varieties. Rapid and intensive accumulation of phenolic compounds and callose were identified as major resistance mechanisms against P. irregulare infection. Together, these new understandings not only provide the foundation for developing new common bean varieties with resistance to Pythium disease under waterlogging conditions, but also open the way for developing novel control methods against Pythium spp