Mlo Resistance to Powdery Mildew (Blumeria graminis f. sp. hordei) in Barley Landraces Collected in Yemen

Jerzy H Czembor,Elżbieta Czembor

doi:10.3390/agronomy11081582

Abstract

Barley (Hordeumvulgare L.) is one of the most important cereal crops in the world. Powdery mildew on barley, which is caused by the pathogen Blumeria graminis f. sp. hordei, occurs world-wide and can result in severe yield loss. Thousands of barley accessions are stored in national gene banks, and their characterization for breeding purposes is needed. This study was conducted to determine the resistance to powdery mildew in 33 barley landraces from Yemen, which were obtained from the ICARDA gene bank. Twenty differential isolates of barley powdery mildew were used. Nine single plant lines were selected from five landraces, based on tests that were performed with 30 plants per landrace, after inoculation with the most avirulent isolate of barley powdery mildew available. Two of these landraces originated from the Al Bayda province in Yemen, and three others originated from Dhamar, Sanaa, and Taizz, respectively. Next, single plant lines were tested using a set of 20 differential isolates of powdery mildew. Two lines that were selected from landrace from the Al Bayda province in Yemen, showed disease reaction designated as 0(4), which is specific for the presence of Mlo resistance. The new source of highly effective Mlo powdery mildew resistance that is described in this study could be used in barley breeding programs.

Highlights

IntroductionBarley is often grown in marginal agricultural areas with low annual precipitation (often less than 220 mm)
Barley (Hordeum vulgare L.) is the fourth most important cereal crop in the world.In many regions, barley is often grown in marginal agricultural areas with low annual precipitation
This study aimed at detecting new sources of powdery mildew resistance in barley landraces that were collected from Yemen, based on the results obtained during testing lines that were selected from these landraces with a set of powdery mildew isolates with different virulence

Summary

Introduction

Barley is often grown in marginal agricultural areas with low annual precipitation (often less than 220 mm) Landraces in these areas are important, as they are often the only rain-fed crop possible and they are cultivated on mountain slopes, at elevations higher than other cereals. They are often grown for grain, and for straw [1]. More than 485,000 accessions of the genus Hordeum are stored at more than institutions worldwide [2] These collections include new and old cultivars, landraces, mutants, breeding lines, and research and mapping plant materials of H. vulgare ssp. These genetic resources are of great value for breeding new cultivars that are well adapted to changing climate and weather anomalies, or more resistant to abiotic and biotic stresses [4,5,6]

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Conclusion