An Improved Method for Measuring Quantitative Resistance to the Wheat PathogenZymoseptoria triticiUsing High-Throughput Automated Image Analysis

• DOI: 10.1094/phyto-01-16-0018-r
• Publication Date: 2016-04-07T00:23:35Z
• Authors: Ethan L. Stewart; Christina H. Hagerty; Alexey Mikaberidze; Christopher C. Mundt; Ziming Zhong; Bruce A. McDonald
• Keywords: Mycosphaerella graminicola; Pycnidium; Host resistance; Inbred strain

Zymoseptoria tritici causes Septoria blotch (STB) on wheat. An improved method of quantifying STB symptoms was developed based automated analysis diseased leaf images made using a flatbed scanner. Naturally infected leaves (n = 949) sampled from fungicide-treated field plots comprising 39 wheat cultivars grown in Switzerland and 9 recombinant inbred lines (RIL) Oregon were included these analyses. Measures quantitative resistance percent area covered by lesions, pycnidia size gray value, density per lesion. These measures obtained automatically with batch-processing macro utilizing the image-processing software ImageJ. All phenotypes both locations showed continuous distribution, as expected for trait. The trait distributions at sites largely overlapping even though host environments quite different. Cultivars RILs could be assigned to two or more statistically different groups each measured phenotype. Traditional visual assessments highly correlated image RILs. results show that provides promising tool assessing Z. under conditions.