Variation between Ethiopian and North American barley varieties (Hordeum vulgare) in response to Russian wheat aphid (Diuraphis noxia) populations.

Alemu Araya,Temam Hussein,Tesfay Belay

doi:10.1093/jis/14.1.40

Alemu Araya, Temam Hussein + Show 1 more

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https://doi.org/10.1093/jis/14.1.40

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Abstract

The Russian wheat aphid, Diuraphis noxia (Mordvilko) (Hemiptera: Aphididae), causes severe damage to barley, Hordeum vulgare L. (Poales: Poaceae), in the highlands of Ethiopia. Little information is available on the control of this pest in Ethiopia. An experiment aimed at evaluating the resistance of barley varieties from the USA to D. noxia populations and determining biotypic variation between Ethiopian and North American D. noxia populations was conducted. The D. noxia -resistant barley varieties Burton and RWA-1758 from the USA, the resistant barley line 3296-15 from Ethiopia, and a local Ethiopian susceptible variety were included in a randomized design in a greenhouse under natural light conditions. There were highly significant differences ( P < 0.001) in the mean D. noxia population, leaf chlorosis, leaf rolling, plant stunting, number of tillers per plant, and the percentage of infested tillers per plant between the resistant and susceptible varieties. The aphid population per tiller was lower on the resistant barley plants than on the susceptible plants. Severe plant damage was observed on the local barley variety, while the least damage was observed on Burton, followed by RWA-1758. Burton and RWA-1758 were therefore highly resistant and moderately resistant, respectively, to the northern Ethiopian D. noxia populations, indicating similarities in biotypes between the United States and northern Ethiopian D. noxia populations. The damage to variety 3296-15 was greater than to Burton and RWA-1758. Leaf chlorosis scores and leaf rolling scores for variety 3296-15 upon treatment with the north Ethiopian D. noxia population indicate likely biotypic variation between D. noxia populations of northern and central Ethiopia.

Highlights

Hordeum vulgare L. (Poales: Poaceae), is one of the earliest and most widely cultivated cereal crops grown in the highlands of Ethiopia (Pohlman 1959)
Barley yields are very low in Ethiopia, but many people believe that barley has a high yield potential (Lakew et al 1993)
The lowest chlorosis score was observed for Burton, and the lowest was for RWA1758 (Table 1)

Summary

Introduction

Hordeum vulgare L. (Poales: Poaceae), is one of the earliest and most widely cultivated cereal crops grown in the highlands of Ethiopia (Pohlman 1959). In the meher (main) season, it is the fifth most common cereal crop after maize, sorghum, tef, and wheat in terms of area coverage and total production (CSA 2010). In the belg (short) season, barley is the second most common cereal crop, after maize, in terms of area coverage and total production (CSA 1996). It is the major cereal crop in the highlands of north Ethiopia during all seasons. Barley yields in Ethiopia were 1.33 and 0.96 t ha-1 in the meher and belg seasons, respectively This is very low compared to the potential maximum yield of 13.3 t ha-1 reported by other sources (FAO 1994). The Russian wheat aphid, Diuraphis noxia (Mordvilko) (Hemiptera: Aphididae), is the major insect that reduces barley yields, and it has a worldwide distribution including the Middle East, USA, South Africa, and Ethiopia (Haile and Ali 1985; Girma et al 1993; Robinson 1994)

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