Background: Genomic discovery in oat and its application to oat improvement have been hindered by a lack of genetic markers common to different genetic maps, and by the difficulty of conducting whole-genome analysis using high-throughput markers. This study was intended to develop, characterize, and apply a large set of oat genetic markers based on Diversity Array Technology (DArT).

Random amplified polymorphic DNA (RAPD) analysis appears to offer a cost-and time-effective alternative to restriction fragment-length polymorphlsm (RFLP) analysis. However, concerns about the ability to compare RAPD results from one laboratory to another have not been addressed effectively. DNA fragments that were amplified by five primers and shown to be reproducibly polymorphic between two oat cultivars (within the Ottawa laboratory) were tested in six other laboratories in North America. Four of the six participants amplified very few or no fragments using the Ottawa protocol. These same participants were able to generate a considerable number of amplified fragments by using their own protocols. The reproducibility of results among laboratories was affected by two factors. First, different laboratories amplified different size ranges of DNA fragments, and, consequently, small and large polymorphic fragments were not always reproduced. Second, although reproducible results were obtained with four of the primers, reproducible resuits were not obtained with the fifth primer, using the same reaction conditions. It is suggested that if the overall temperature profiles (especially the annealing temperature) in-MATERIALS AND METHODS RAPD primers were obtained from Dr.

Molecular mapping of cultivated oats was conducted to update the previous reference map constructed using a recombinant inbred (RI) population derived from Avena byzantina C. Koch cv. Kanota x Avena sativa L. cv. Ogle. In the current work, 607 new markers were scored, many on a larger set of RI lines (133 vs. 71) than previously reported. A robust, updated framework map was developed to resolve linkage associations among 286 markers. The remaining 880 markers were placed individually within the most likely framework interval using chi2 tests. This molecular framework incorporates and builds on previous studies, including physical mapping and linkage mapping in additional oat populations. The resulting map provides a common tool for use by oat researchers concerned with structural genomics, functional genomics, and molecular breeding.

The genetic model for maturity in soybean [Glycine max (L.) Merr.] is a series of near‐isogenic lines, but they do not span the natural variation for early maturity. The objectives of this study were to determine if a single gene in OT98‐17 controls early maturity and if this is a new locus. A cross was made between ‘Maple Presto’ and OT98‐17, an early‐maturing Maple Presto–derived backcross line. A total of 201 F3 progeny rows from this population and Maple Presto were grown at Ottawa, ON, in 1999. In 2000, F4 progeny rows were grown and 150 late‐maturing and 51 early‐maturing families were observed to fit a 3:1 ratio (n = 201, X2 = 0.01, P = 0.90). The early‐maturing allele was transferred to a ‘Harosoy’ background, and isolines were grown from 2002 to 2006 at Ottawa, ON. The isolines were 9 and 6 d earlier maturing in Maple Presto and Harosoy backgrounds, respectively. To determine the independence of this locus, simple sequence repeat molecular markers were used to identify three candidate regions. The gene E8 specifically mapped to linkage group C1 between Sat_404 and Satt136. No other maturity gene has been mapped to this region. The two other candidate regions were both related to maturity quantitative trait loci on molecular linkage group L and may be inadvertently selected along with early maturity. The gene symbol E8e8 has been assigned by the Soybean Genetics Committee. E8E8 results in later maturity and e8e8 results in early maturity. The earliest Harosoy maturity isoline is now rated as maturity group 000.

In spring-type oat ( Avena sativa L.), quantitative trait loci (QTLs) detected in adapted populations may have the greatest potential for improving germplasm via marker-assisted selection. An F(6) recombinant inbred (RI) population was developed from a cross between two Canadian spring oat varieties: 'Terra', a hulless line, and 'Marion', an elite covered-seeded line. A molecular linkage map was generated using 430 AFLP, RFLP, RAPD, SCAR, and phenotypic markers scored on 101 RI lines. This map was refined by selecting a robust set of 124 framework markers that mapped to 35 linkage groups and contained 35 unlinked loci. One hundred one lines grown in up to 13 field environments in Canada and the United States between 1992 and 1997 were evaluated for 16 agronomic, kernel, and chemical composition traits. QTLs were localized using three detection methods with an experiment-wide error rate of approximately 0.05 for each trait. In total, 34 main-effect QTLs affecting the following traits were identified: heading date, plant height, lodging, visual score, grain yield, kernel weight, milling yield, test weight, thin and plump kernels, groat beta-glucan concentration, oil concentration, and protein. Several of these correspond to QTLs in homologous or homoeologous regions reported in other oat QTL studies. Twenty-four QTL-by-environment interactions and three epistatic interactions were also detected. The locus controlling the covered/hulless character ( N1) affected most of the traits measured in this study. Additive QTL models with N1 as a covariate were superior to models based on separate covered and hulless sub-populations. This approach is recommended for other populations segregating for major genes. Marker-trait associations identified in this study have considerable potential for use in marker-assisted selection strategies to improve traits within spring oat breeding programs.

E10 is a new maturity locus in soybean and FT4 is the predicted/potential functional gene underlying the locus. Flowering and maturity time traits play crucial roles in economic soybean production. Early maturity is critical for north and west expansion of soybean in Canada. To date, 11 genes/loci have been identified which control time to flowering and maturity; however, the molecular bases of almost half of them are not yet clear. We have identified a new maturity locus called "E10" located at the end of chromosome Gm08. The gene symbol E10e10 has been approved by the Soybean Genetics Committee. The e10e10 genotype results in 5-10 days earlier maturity than E10E10. A set of presumed E10E10 and e10e10 genotypes was used to identify contrasting SSR and SNP haplotypes. These haplotypes, and their association with maturity, were maintained through five backcross generations. A functional genomics approach using a predicted protein-protein interaction (PPI) approach (Protein-protein Interaction Prediction Engine, PIPE) was used to investigate approximately 75 genes located in the genomic region that SSR and SNP analyses identified as the location of the E10 locus. The PPI analysis identified FT4 as the most likely candidate gene underlying the E10 locus. Sequence analysis of the two FT4 alleles identified three SNPs, in the 5'UTR, 3'UTR and fourth exon in the coding region, which result in differential mRNA structures. Allele-specific markers were developed for this locus and are available for soybean breeders to efficiently develop earlier maturing cultivars using molecular marker assisted breeding.

Soybean near isogenic lines (NILs), contrasting for maturity and photoperiod sensitivity loci, were genotyped with approximately 430 mapped simple sequence repeats (SSRs), also known as microsatellite markers. By analysis of allele distributions across the NILs, it was possible to confirm the map location of the Dt1 indeterminate growth locus, to refine the SSR mapping of the T tawny pubescence locus, to map E1 and E3 maturity loci with molecular markers, and to map the E4 and E7 maturity loci for the first time. Molecular markers flanking these loci are now available for marker-assisted breeding for these traits. Analysis of map locations identified a putative homologous relationship among four chromosomal regions; one in the middle of linkage group (LG) C2 carrying E1 and E7, one on LG I carrying E4, one at the top of LG C2, at which there is a reproductive period quantitative trait locus (QTL), and the fourth on LG B1. Other evidence suggests that homology also exists between the E1 + E7 region on LG C2 and a region on LG L linked to a pod maturity QTL. Homology relationships predict possible locations in the soybean genome of additional maturity loci, as well as which maturity loci may share a common evolutionary origin and similar mechanism(s) of action.

A molecular linkage map of cultivated oat composed of 561 loci has been developed using 71 recombinant inbred lines from a cross between Avena byzantina cv. Kanota and A. sativa cv. Ogle. The loci are mainly restriction fragment length polymorphisms detected by oat cDNA clones from leaf, endosperm, and root tissue, as well as by barley leaf cDNA clones. The loci form 38 linkage groups ranging in size from 0.0 to 122.1 cM (mean, 39 cM) and consist of 2-51 loci each (mean, 14). Twenty-nine loci remain unlinked. The current map size is 1482 cM and the total size, on the basis of the number of unlinked loci, is estimated to be 2932.0 cM. This indicates that this map covers at least 50% of the cultivated oat genome. Comparisons with an A-genome diploid oat map and between linkage groups exhibiting homoeology to each other indicate that several major chromosomal rearrangements exist in cultivated oat. This map provides a tool for marker-assisted selection, quantitative trait loci analyses, and studies of genome organization in oat.