Phenotypic Variation within Local Populations of Meadow Fescue Shows Significant Associations with Allele Frequencies at AFLP Loci

To identify markers useful for Marker Assisted Selection (MAS), mapping families are usually constructed and used for Quantitative Trait Loci (QTL) mapping. Association mapping offers an alternative strategy for marker development using already characterized germplasm, preferably from natural populations. Simultaneous phenotypic and molecular screening of gene bank accessions can reveal associations between molecular marker alleles and phenotypic traits, and lead to a more targeted construction of mapping families for fine-mapping. In this investigation, we combine molecular (AFLP) and phenotypic data of 15 Norwegian local populations and 5 Nordic cultivars in order to identify markers associated with phenotypic traits of interest

Isolation of Candidate Genes Involved in Cold Temperatures Response in \u3cem\u3eFestuca Pratensis\u3c/em\u3e Huds., Using Suppression Subtractive Hybridisation and Microarray Approaches

The objective of this work was to isolate candidate genes which are differentially expressed following cold-acclimation and develop SNPs to test for associations between candidate genes and frost tolerance. The ability to develop sufficient levels of tolerance against freezing temperatures through cold-acclimation (hardening) is crucial for survival of grasses and winter cereals in temperate climate. Meadow fescue (Festauca pratensis Huds.) is one of the most important forage grass species in Northern Europe. The preference of Festuca instead of Lolium in Norway is due to its superior combination of winter hardiness and forage quality

QTL Analysis of Vernalisation Requirement and Heading Traits in \u3cem\u3eFestuca Pratensis\u3c/em\u3e Huds.

The transition from the vegetative phase to the reproductive phase occurs as a result of environmental and endogenous stimuli. In Festuca pratensis, low temperature and/or short days over a certain period (primary induction) followed by long days (secondary induction) will lead to heading and flowering (Heide, 1988). We present results from QTL mapping of vernalisation requirement and heading traits and mapping of the Vrn-1 ortholog in F. pratensis

Locating, and Utilising \u3cem\u3eFestuca Pratensis\u3c/em\u3e Genes for Winter Hardiness for the Future Development of More Persistent High Quality \u3cem\u3eLolium\u3c/em\u3e Cultivars

Genes for freezing-tolerance and winter hardiness were located in Festuca pratensis by QTL analysis and introgression-mapping. QTL for freezing-tolerance on F. pratensis chromosome 4 were orthologous to rice chromosome 3, and Triticeae chromosome 5. Increased energy dissipation during the autumn through a lower maximum quantum yield of photosystem II (PSII) was correlated with improved winter survival. Freezing tolerance in Lolium was achieved by the transfer and subsequent expression of F. pratensis genes from chromosome 4 that govern the expression of a non-photochemical (NPQ) mechanism for the dissipation of excess light energy under low temperature

Cultivar diversity in nordic spring barley breeding (1930-1991)

A phenotypic diversity index (PDI) was calculated using 10 agronomic characteristics recorded in 90 accessions of 2-row spring barleys and 29accessions of 6-row spring barleys grown in the Nordic Region. The PDI ranged from 0.0308 to 0.6245 in 2-row barley accessions and from0.0314 to 0.7016 in 6-row barley accessions. The average PDIs were0.2178 and 0.2438 in 2-row and 6-row barley germplasm, which confirms that some older cultivars were parents of newer cultivars. The lowest PDI was between accessions with the same name, which suggest that irrespective of their market source, they were the same cultivars. The largest PDI ranges in 2-row barley cultivars within the same country or release decade were correlated to the number of accessions in the respective cluster, which suggests that phenotypic diversity in this germplasm depends on the number of cultivars included in the cluster. However, this association was not always observed in 6-row barley cultivars. The most distinct 2-row cultivars were Arla and Akka from Sweden, whereas Sigur and Tampa from Iceland were the most distinct 6-row cultivars as determined by both PDI and average linkage cluster analysis. This analysis also confirm that the 2-row barley accessions Jenny, Triumph, and Vega, which were obtained from two distinct market sources, and the 6-row barley accessions under the name Agneta (but from three market sources) were the same. The analysis of variance of the PDI indicates that 6-row germplasm may be clustered according to their geographical origin or decade of release, but this was not observed in 2-row barley germplasm. This research demonstrates the advantage of PDI to assess variation among breeding pools

Analysis of the genotypebyenvironment interaction of spring barley tested in the Nordic Region of Europe: relationships among stability statistics for grain yield

Variation in agronomic and quality characteristics was investigated in 220 Nordic spring barley cultivars across distinct environments (6 locations during 3 years) in the Nordic Region of Europe. The objectives of this research were to determine the importance of the genotype by environment interaction in all characteristics evaluated and to establish the relationship among different stability statistics for grain yield. Combined analysis of variance across locations indicated that both environments and genotype by environment interactions influenced significantly the cultivar phenotypes for all characteristics, irrespective of their type (row number) or earliness. The first two interaction principal component axes of the additive-main-effects-and-multiplicative-interaction (AMMI) model accounted together between 35% and 75% of the total genotype-by-environment interaction for all characteristics. Grain yield was, on average, higher in 2-row than in 6-row cultivars, which were significantly earlier in heading and grain maturity than the former. However, in some of the most northern locations, 6-row barley cultivars significantly outyielded on average 2-row barley lines. The genotype by location interaction variance (σ2 GL) accounted by each genotype was significantly associated to the deviation from regression (Tai's λ) while the coefficient of regression (β) was significantly correlated to the IPCA1 and IPCA2 of the AMMI model in 2-row, 6-row and early barley cultivars