Geographical Distribution of Physiologic Races of Puccinia triticina and Postulation of Resistance Genes in New Wheat Cultivars in Egypt

Nour E K Soliman,Ashraf M M Abdelbacki,Reda I Omara,Mohammad A.A Najeeb

doi:10.33687/phytopath.001.01.0018

Nour E K Soliman, Ashraf M M Abdelbacki + Show 2 more

Open Access

https://doi.org/10.33687/phytopath.001.01.0018

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Abstract

Knowledge of the geographical distribution for physiologic races of Puccinia triticina and identification of leaf rust resistance genes (Lr ,s) in the recent Egyptian wheat cultivars are essential for maximizing resistance in future-bred cultivars. The aim of this study was to know the status of resistance in Egyptian wheat cultivars against wheat leaf rust and the most frequent race distributed. Infected samples were collected from five Governorates, i.e., Dakahlia, Kafr el-Sheikh, Beheira, Sharqia and Sohag comprised the wheat growing area in Egypt. These samples were isolated, purified and identified on the differential stes. Gene postulation was done using fifteen identified races on Egyptian wheat cultivars correlated with Lr genes. Thirty three races identified during three seasons 2009/2010, 2010/2011 and 2011/2012. The most frequent race was TK (10%) followed by race BB (7.58%), PK (6.55%), TT (4.82%), PT (3.79%) and MT (3.44%). Moreover, races; BB, TT and PT were present during three seasons while these races appeared in some Governorates and disappeared in other Governorates. On the other hand, the most frequently occurring gene in ten Egyptian wheat cultivars was Lr35 (70%), followed by Lr22 (60%), Lr27 (40%), Lr34 (30%), Lr19 (30%),Lr18 (10%),Lr36 (10%) and Lr46 (10%), eight out of sixteen Lr genes were not present in the tested cultivars. It is concluded that there was a good variation in Lr genes carried by wheat cultivars commercially grown in Egypt. Therefore, strategies for deploying resistance genes to prolong effective disease resistance are suggested to control wheat leaf rust disease.

Highlights

Wheat leaf rust, caused by Puccinia triticina, is one of the most common diseases of wheat worldwide
Samples were collected from wheat Egypt farmers and wheat Trap Rust Nurseries (EWTRN), which incorporate monogenic lines of leaf rust (Lr's), certain local cvs. and highly susceptible check varieties viz. “
The highest mean in collected leaf rust samples was in Kafr el-Sheikh followed by Dakahlia and Sharqia while Sohag was the lowest one

Summary

Introduction

Wheat leaf rust, caused by Puccinia triticina, is one of the most common diseases of wheat worldwide. It probably results in higher total annual losses worldwide because of its more frequent and widespread occurrence (Huerta-Espino et al, 2011). In. Egypt, leaf rust is the most common and important wheat disease. Leaf rust is the most common and important wheat disease It caused severe losses in grain yield which reached 23% on some varieties depending on the level of rust incidence and the stage of crop development when initial infection occurs (Nazim et al, and Kassem et al, 2011). The use of resistant cultivars is the most efficient, economical and environmentally safe method to control leaf rust disease. There are about 60 known genes involved in the resistance of wheat cvs. There are about 60 known genes involved in the resistance of wheat cvs. to P

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