Field-based assessment of genetic diversity for leaf rust resistance and yield attributes in the locally developed wheat cultivars using multivariate analysis

Brown leaf rust severely affects the production of wheat crop and causes economic losses worldwide. In the present study, evaluation of the locally developed wheat cultivars collection consisting of 133 varieties and lines was done to assess local diversity against leaf rust disease and yield attributes under natural conditions in Faisalabad, Pakistan. For this purpose, a field trial was conducted in Faisalabad, Pakistan under a randomized complete block design (RCBD). Various multivariate analyses were carried out including analysis of variance (ANOVA), correlation analysis, principal component analysis and cluster analysis to assess varietal response under rust diseased conditions. Twenty-six cultivars were shown to have an resistant (R) type response; while moderately resistant (MR),moderately resistant moderately susceptible (MRMS), moderately susceptible (MS) and susceptible (S) responses were demonstrated by 47, 16, 16, and 28 germplasm accessions, respectively. Analysis of variance indicated that, all the verities have highly significant difference for all the characters. The Pearson’s correlation coefficients revealed that grain yield per plant was positively correlated with most yield attributes, but negatively correlated with disease severity. Principal component (PC) analysis indicated that five PCs have an Eigenvalue >1 and contributed 78.4% to the total variability while rest of 6 attributes contributed (21.6%) between wheat cultivars evaluated for different characters. Cluster analysis categorized the 133 genotypes into five different clusters. The members of the 4 th cluster showed maximum divergence from the members of 3 rd clusters. On the other hand, the members of 1 st and 2nd clusters showed the maximum similarities according to D2 statistics. Scatter plot showed that the genetic variation in the studied germplasm accessions and this diversity can be used for breeding programs aimed at improvement of disease resistance in the wheat germplasm. It concludes that there is significant diversity among the locally developed wheat germplasm for both leaf rust resistance and yield attributes. The present study, clearly emphasize the importance of resistant varieties which are great edge to the farmers in order to prevent yield losses