Variation and Correlations among European and North American Orchardgrass Germplasm for Herbage Yield and Nutritive Value

Joseph Robins,Greg Blaser,B Bushman,Ulf Feuerstein

doi:10.3390/agronomy6040061

Abstract

Efforts to improve water-soluble carbohydrate (WSC) concentrations are common in perennial forage grass breeding. Perennial ryegrass (Lolium perenne) breeding has been very successful in developing new cultivars with high WSC and high agronomic performance. Breeding efforts are ongoing to improve the WSC of other perennial forage grasses, such as orchardgrass (Dactylis glomerata). The United States Department of Agriculture Forage and Range and Deutsche Saatveredelung orchardgrass breeding programs cooperated to characterize the expression and genotype by environment interaction (GEI) of water-soluble carbohydrates in a collection of orchardgrass populations from both breeding programs. Additionally, the effort characterized the relationship between water-soluble carbohydrates and other agronomic and nutritive value traits in these populations. Overall, the Deutsche Saatveredelung populations had higher herbage mass (15%), rust resistance (59%), and later maturity. The Forage and Range Research populations had higher water-soluble carbohydrates (4%), nutritive value, and earlier maturity. However, results were highly dependent on GEI. Differences were very pronounced at the French and German field locations, but less pronounced at the two US locations. Combining the germplasm from the Forage and Range Research and Deutsche Saatveredelung programs may be a way to develop an improved base germplasm source that could then be used separately in the EU and US for water-soluble carbohydrate and other trait improvement.

Highlights

Orchardgrass (Dactylis glomerata) is an auto-tetraploid, out-crossing forage grass, and is one of the main perennial grasses used for grazing and hay production in temperate climates [1]
Orchardgrass is highly preferred by livestock, exhibits early season growth, and is one of the most compatible perennial forage grasses when sown with perennial legumes, e.g., alfalfa (Medicago sativa L.) [1,3,4]
In the study described we examine the effect of differing environments in North America (US) and Europe (EU) on the expression of water-soluble carbohydrate (WSC), and the relationship between WSC and associated agronomic and nutritive value traits in populations of orchardgrass from the North American

Summary

Introduction

Orchardgrass (Dactylis glomerata) is an auto-tetraploid, out-crossing forage grass, and is one of the main perennial grasses used for grazing and hay production in temperate climates [1]. D. glomerata is the sole species in the Dactylis genus, the species includes both Mediterranean and Continental ecogeographic subspecies that are diploid and tetraploid [2]. Orchardgrass is highly preferred by livestock, exhibits early season growth, and is one of the most compatible perennial forage grasses when sown with perennial legumes, e.g., alfalfa (Medicago sativa L.) [1,3,4]. It is less tolerant to abiotic stresses than tall fescue and, for winter injury, than timothy, but more tolerant than perennial ryegrass. The forage quality of orchardgrass is intermediate, less than perennial ryegrass (Lolium perenne), equal to timothy (Phleum pratense), but greater than tall fescue (Lolium arundinaceum).

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Conclusion