Virulence and Molecular Polymorphism of Puccinia Triticina Pathotypes in Egypt

Walid M El-Orabey,Aladdin Hamwieh,Mohamed A Gad,Shaimaa M Ahmed

doi:10.33687/phytopath.008.03.3087

Abstract

Forty wheat leaf rust (Puccinia triticina) pathotypes were collected from eleven Egyptian governorates during the two growing seasons 2016/2017 and 2017/2018 were analyzed based on both virulence and molecular marker analysis. Virulence analysis was carried out on the basis of infection type of the tested pathotypes on 20 differential monogenic lines, each carrying single leaf rust resistance genes (Lr). Six simple sequence repeats (SSR) markers were used for molecular characterization of P. triticina to detect the genotypic variation among pathotypes. Almost all of the tested pathotypes were phenotypically and genetically varied that confirms a high diversity within Egyptian leaf rust populations. Cluster analysis based on both virulence analysis and molecular patterns classified the tested pathotypes to three main groups. A relatively weak correlation was found between virulence and molecular analysis (r = 0.03). High similarity was found between leaf rust populations in the three governorates; Sohag, Bani Sweif and Fayoum. Also, high similarity was found between leaf rust populations in the five; Egyptian governorates; Minufiya, Kafr-Elsheikh, Gharbiya, Alexandria and Qalyubia, while, wide variation was found between leaf rust populations of the three governorates; Beheira, Sharqiya and Dakahlia. The results of this study support using molecular markers analysis to estimate genetic diversity between P. triticina pathotypes.

Highlights

Leaf rust caused by P. triticina is the most common and widespread rust disease as it was annually found everywhere wheat (Triticum aestivum L.) is grown in Egypt and worldwide
This study revealed that, there was a high diversity among leaf rust populations in Egypt due to the selection pressure and migration
Several different molecular markers were used as the most effective method to estimate the genetic variation in P. triticina populations which provide direct information concerning the effects of host selection in the potential effectiveness of leaf rust resistance genes (Kolmer, 1999)

Summary

Introduction

Leaf rust caused by P. triticina is the most common and widespread rust disease as it was annually found everywhere wheat (Triticum aestivum L.) is grown in Egypt and worldwide. Wide variations and high diversity of virulence in P. triticina populations in Egypt, mainly due to high selection pressure and migration, are the main two evolutionary forces for the emergence of many new leaf rust pathotypes (McVey et al, 2004).

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Results

Conclusion