Nonparametric stability analysis for disease properties of common bunt in wheat

Common bunt, also known as stinking smuts or stinking smut, causes a considerable decrease in the yield performance and quality of both winter and spring kinds of wheat. This research aimed to identify the stability properties of resistance to common bunt among 150 wheat genotypes using three measurements, disease severity (DS), coefficient of infection (CI), and infection type (IT). Field trials were conducted in three locations, Maragheh, Kermanshah, and Kurdistan during 2018-2020. Stability analysis was performed via fourteen nonparametric stability statistics. Results showed that genotypes G38 and G63 were the most favorable genotypes based on nonparametric stability statistics as well as high disease resistance according to DS, CI, and IT measurements. The circular dendrograms of DS, CI, and IT, classified wheat genotypes into ten clusters whereas cluster II must be considered based on DS and stability while for simultaneous selection of stable as well as resistant genotypes based on IT, cluster IX following cluster X must be regarded. The simultaneous selection of the most stable, as well as most resistant genotypes based on CI, was not possible. The first factor separated the S3, S6, Fox, and MR as well as DS from the other methods in the plot of factor analysis while in the CI plot, the first factor separated the methods NS1, NS2, and MR from the other methods and in IT, the first factor separates the IT as well as MR and Fox from the other methods and illustrated dynamic stability concept. The Fox and MR methods can be used for stability analysis because they are consistently related to resistance and the dynamic stability concept.