Seed to Seedling Transmission of Colletotrichum lindemuthianum in Dry Edible Pinto Bean

Abstract

Dry bean anthracnose, caused by Colletotrichum lindemuthianum, is a damaging disease that can cause significant reductions in seed quality and yield. The purpose of this study was to determine the races of C. lindemuthianum isolates collected in North Dakota and to develop a real-time qPCR assay to quantify the pathogen in seed and stem tissue. Race 73 continues to be the most common in North Dakota across 33 isolates collected in 2012. The qPCR assay using primer pair ClF1527/ClR1609 was proven useful for quantifying C. lindemuthianum, and was more specific than a previously developed method. Results from greenhouse and field studies indicated that as seed infection increased, emergence decreased and foliar symptoms and pathogen detection increased. Additionally, field studies demonstrated daughter seed infection increased and yield decreased as seed infection severity increased. Using primer pair ClF1527/ClR1609, the pathogen was detected ten days after planting in greenhouse and field studies.