Marker‐Assisted Selection for Neutral Detergent Fiber in Smooth Bromegrass

Abstract

Neutral detergent fiber (NDF) is the most effective and measurable predictor of animal intake. About 70% of the variation in animal production is attributed to differences in intake potential of livestock feed. Sixteen molecular markers associated with NDF in four divergently selected smooth bromegrass (Bromus inermis L.) populations were selected from a previous study for further examination for possible use in a marker-assisted selection (MAS) breeding program. The objectives of this experiment were to confirm the association of previously identified markers to NDF concentration in smooth bromegrass populations and to develop a marker-based selection index. Marker and NDF data were analyzed and marker indices were constructed using data from the current and previous studies. Index scores were used to rank genotypes and create selection differentials on the basis of phenotypic data. Marker frequencies calculated on a subpopulation basis between the previous and current studies were highly unrepeatable. Nevertheless, of the 14 groups of marker indices, seven of which accounted for pedigree structure, one marker index appears to provide the greatest potential for use in MAS to reduce NDF across all four populations of smooth bromegrass. Where pedigree structure is known, selections made using this index would lead to the largest expected response per year and eliminate the need to collect phenotypic data for as long as linkage relationships remain intact. Where pedigree structure is unknown, a general marker index may be used, or phenotypic data can be utilized along with a marker index. However, inclusion of phenotypic data would necessitate a cost-benefit analysis.

Phenotypic and QTL analyses of herbage production-related traits in perennial ryegrass (Lolium perenne L.)

“…Implementation of QTL-linked markers in MAS presents a challenge in forage breeding and there are few reports describing MAS (Humphreys and Turner 2001;Stendal et al 2006;Dolstra et al 2007), particularly application of QTL discoveries into genetic backgrounds discrete from the original discovery population. For the current QTL, a programme of MAS is in progress that will simultaneously enable validation of effects and estimate response to selection in multi-parent breeding populations related to population I 9 S. This is similar to the strategy adopted by Dolstra et al (2007), but includes an intermediate step wherein beneficial marker alleles specific to the breeding population are designated prior to selection.…”

Potential for marker-assisted selection for forest tree breeding: lessons from 20 years of MAS in crops

“…RAPD and their derived sequence-characterized amplified regions (SCAR) markers have been used to predict quantitative traits such as polyphenol content in the aerial parts of the medicinal plant Echinacea purpurea (Chen et al 2009), sprouting resistance in rye (Twardowska et al 2005), neutral detergent fiber fraction in smooth bromegrass (Stendal et al 2006), and oleic acid content in spring turnip rape (Tanhuanpää and Vilkki 1999). Applications of MAS in species for which genomic resources are still scarce are however limited (only 8 examples out of 250 papers reporting the application of MAS in our survey).…”

Genetic analysis of agronomic traits associated with plant architecture by QTL mapping in maize

“…MAS is a combination of traditional genetics and molecular biology and allows for the selection of genes that control traits of interest. Combined with traditional selection techniques, MAS has emerged as a valuable tool for selecting organisms with interesting traits during crop breeding (Stendal et al, 2006;Chen et al, 2010;Kumar et al, 2010;Jantaboon et al, 2011).…”