Comparison of three methods for assessing disease reaction to Mycosphaerella pinodes in field pea (Pisum sativum)

The susceptibility to mycosphaerella blight caused by Mycosphaerella pinodes in pea (Pisum sativum) was evaluated on 48 genotypes using three assessment methods; i) field ratings over four station-years, ii) inoculation in growth chambers, and iii) detached-leaf assays. None of the genotypes were completely resistant, and the reaction of lines with intermediate levels of susceptibility was only weakly correlated among the three methods. However, all three methods identified the same groups of lines as the most susceptible and resistant lines in the study. The cultivars 'Radley', 'Badminton', 'Logan', 'Miko', 'Carneval', and 'CEB1171' were moderately resistant to Mycosphaerella blight, while 'PI 179449', 'Yellowhead', 'JI 181', and 'JI 252' were very susceptible. We conclude that a detached leaf assay could be used as a pre-screening technique to reduce the number of lines assessed in (more expensive and time consuming) assessments under field conditions.