Evaluating leaf rust reactions of pure bread wheat landrace lines using non-parametric statistics

This research aims to assess genotype × environment interactions (G × E) of the leaf rust (Puccinia triticina) reactions of 29 Turkish landrace-derived pure lines over seven environments. Field experiments were conducted in Çanakkale, Edirne and Samsun (Turkey) in three consecutive growing seasons from 2011-2012 to 2013–2014 under natural conditions. Leaf rust reactions of genotypes were recorded in accordance with the Modified Cobb scale. Genotype stabilities assessed by non-parametric stability statistics. Furthermore, a Principal Component Analysis (PCA) biplot of non- parametric stability statistics were used to compare their capability for capturing both stability and leaf rust reactions of genotypes in the given dataset. PCA Biplot results showed that non-parametric parameters of Thennarasu and Percentage Availability (PA) showed a positive association with mean disease severity while Rank Means (RM) were negatively associated. Non-parametric stability analyses revealed that Genotypes 29, 25 and 15 were the most stable pure lines when only 25 and 15 could be considered as resistant-stable. In order to determine both stability and leaf rust resistance in bread wheat, PA and RM are recommended.