Showing papers by "Scott D. Haley published in 2017"
TL;DR: Among the consistent QTL, five QTL had significant epistatic interactions (additive × additive) at least for one trait and none revealed significant additive × additive × environment interactions.
Abstract: Stable quantitative trait loci (QTL) are important for deployment in marker assisted selection in wheat (Triticum aestivum L.) and other crops. We reported QTL discovery in wheat using a population of 217 recombinant inbred lines and multiple statistical approach including multi-environment, multi-trait and epistatic interactions analysis. We detected nine consistent QTL linked to different traits on chromosomes 1A, 2A, 2B, 5A, 5B, 6A, 6B and 7A. Grain yield QTL were detected on chromosomes 2B.1 and 5B across three or four models of GenStat, MapQTL, and QTLNetwork while the QTL on chromosomes 5A.1, 6A.2, and 7A.1 were only significant with yield from one or two models. The phenotypic variation explained (PVE) by the QTL on 2B.1 ranged from 3.3-25.1% based on single and multi-environment models in GenStat and was pleiotropic or co-located with maturity (days to heading) and yield related traits (test weight, thousand kernel weight, harvest index). The QTL on 5B at 211 cM had PVE range of 1.8-9.3% and had no significant pleiotropic effects. Other consistent QTL detected in this study were linked to yield related traits and agronomic traits. The QTL on 1A was consistent for the number of spikes m-2 across environments and all the four analysis models with a PVE range of 5.8-8.6%. QTL for kernels spike-1 were found in chromosomes 1A, 2A.1, 2B.1, 6A.2, and 7A.1 with PVE ranged from 5.6-12.8% while QTL for thousand kernel weight were located on chromosomes 1A, 2B.1, 5A.1, 6A.2, 6B.1 and 7A.1 with PVEranged from 2.7-19.5%. Among the consistent QTL, five QTL had significant epistatic interactions (additive × additive) at least for one trait and none revealed significant additive × additive × environment interactions. Comparative analysis revealed that the region within the confidence interval of the QTL on 5B from 211.4-244.2 cM is also linked to genes for aspartate-semialdehyde dehydrogenase, splicing regulatory glutamine/lysine-rich protein 1 isoform X1, and UDP-glucose 6-dehydrogenase 1-like isoform X1. The stable QTL could be important for further validation, high throughput SNP development, and marker-assisted selection (MAS) in wheat.
47 citations
TL;DR: The KASP SNPs developed in this study should be useful for marker-assisted selection of WSM2 in wheat breeding programs, and the newly constructed map will also facilitate map based cloning of Wsm2.
Abstract: Wheat streak mosaic virus (WSMV) can cause significant yield loss in wheat (Triticum aestivum L.) in the Great Plains of North America. A recently identified WSMV resistance gene, Wsm2, was mapped to chromosome 3BS in germplasm line ‘CO960293–2’. Effective genetic markers tightly linked to the gene will enhance the selection of WSMV-resistant lines through marker-assisted selection. We have mapped Wsm2 using a high-density map developed from the wheat 90K Infinium iSelect single-nucleotide polymorphism (SNP) array with recombinant inbred lines from the cross between CO960293–2 and susceptible cultivar ‘TAM 111’. Array-based SNPs that mapped within 4 cM of Wsm2 on chromosome 3BS were converted to Kompetitive Allele Specific Polymerase Chain Reaction (KASP) assays in this study. Six KASP SNPs were validated in two doubled haploid populations developed from crosses of ‘RonL’ × ‘Ripper’ and ‘Snowmass’ × ‘Antero’. RonL and Snowmass possess the Wsm2 gene from CO960293–2. Three closely linked KASP SNPs, converted from IAAV6442, BS00018764_51, and wsnp_Ra_c16264_24873670, showed high sensitivity and specificity (0.83 ≤ sensitivity ≤ 0.97, 0.89 ≤ specificity ≤ 0.99). The latter two were also validated in six F₂ breeding populations. These three KASP SNPs were effective in differentiating resistant and susceptible genotypes. Comparative mapping was performed using sequences of SNPs flanking Wsm2 and identified candidate genes and regions in Brachypodium and rice (Oryza sativa L. ssp. japonica). The KASP SNPs developed in this study should be useful for marker-assisted selection of Wsm2 in wheat breeding programs, and the newly constructed map will also facilitate map based cloning of Wsm2.
26 citations
19 citations
TL;DR: It has been observed that the efficiency of doubled haploid production depends on both maize and wheat genotypes, good plant health and proper greenhouse conditions, and proper conduct of all procedures, and the procedures may need minor modification in order to produce higher numbers of embryos, haploid green plants, and doubled haploids.
Abstract: In traditional wheat breeding, the uniformity of lines derived from a breeding population is obtained by repeated selfing from the F1 which takes several generations to reach homozygosity in loci controlling traits of interest. Using doubled haploid technology, however, it is possible to attain 100% homozygosity at all loci in a single generation and completely homogeneous breeding lines can be obtained in 1-2 years. Thus, doubled haploid technology may significantly reduce cultivar development time. Two major methods for producing wheat doubled haploids are androgenesis (anther culture and microspore culture) and embryo culture using wheat-maize wide hybridization, the latter being the most effective and widely used method. The method of wide hybridization between wheat and maize is laborious but is widely successful for rapidly obtaining homozygous lines. This technique includes six major steps: emasculation of the wheat flower; pollination of the emasculated flower with maize pollen; hormone treatment; embryo rescue; haploid plant regeneration in tissue culture medium; and chromosome doubling. It has been observed that the efficiency of doubled haploid production depends on both maize and wheat genotypes, good plant health and proper greenhouse conditions (without disease, insects, or drought stress), and proper conduct of all procedures. Therefore, the procedures may need minor modification in order to produce higher numbers of embryos, haploid green plants, and doubled haploid plants.
19 citations
TL;DR: The objectives were to confirm the previously identified QTL, using recombinant inbred line (RIL) and BC3F2:3 populations developed from the same parents; and test the effects of combinations of alleles at three marker loci in the target chromosome regions.
Abstract: Validating positions and effects of putative quantitative trait loci (QTL) is an important step before employing linked markers in marker-assisted selection (MAS) or conducting finer-scale mapping. Previously, QTL for grain quality traits were identified in a population of 185 doubled haploid (DH) winter wheat (Triticum aestivum L.) lines developed from the cross CO940610/’Platte’. Clusters of QTL for grain quality traits were detected on chromosomes 1B, 6B, and 7B. Our objectives were to (1) confirm the previously identified QTL, using recombinant inbred line (RIL, n = 186) and BC3F2:3 (n = 35) populations developed from the same parents; and (2) test the effects of combinations of alleles at three marker loci in the target chromosome regions. Field trials were conducted in two Colorado environments for the RIL population in 2009/10 and three environments for the BC3F2:3 population in 2012/13. Most QTL previously detected for grain quality traits on 1B, 6B, and 7B were repeated in either the RIL or BC3F2:3 populations, although these QTL were not robust across populations and environments. However, the QTL for grain ash concentration (Gac) on 7B was detected in all environments and populations, with Platte contributing the higher value allele. The BC3F2:3 lines with the allelic combination predicted to have higher grain protein concentration (Gpc) surpassed the lowest predicted combination in one of three environments investigated. Based on these evaluations, marker Bx7-MAR on 1B and the regions around markers Xwmc182a on 6B and Xwmc182b on 7B are recommended for further research for improving grain quality traits.
12 citations
TL;DR: ‘Sunshine’ (Reg. CV-1129, PI 674741) hard white winter wheat (Triticum aestivum L.) was developed by the Colorado Agricultural Experiment Station and released in August 2014 through a marketing agreement with the Colorado Wheat Research Foundation.
Abstract: ‘Sunshine’ (Reg. No. CV-1129, PI 674741) hard white winter wheat (Triticum aestivum L.) was developed by the Colorado Agricultural Experiment Station and released in August 2014 through a marketing agreement with the Colorado Wheat Research Foundation. In addition to researchers at Colorado State University, USDA-ARS researchers at Manhattan, KS, St. Paul, MN, and Pullman, WA participated in its development. Sunshine was developed with the objective of making available a hard white winter wheat cultivar with improved grain yield and straw strength and similar milling and baking qualities to ‘Snowmass’ hard white winter wheat. Both Snowmass and Sunshine are grown in Colorado and adjacent areas of the west-central Great Plains in an identity-preserved marketing system whereby a grower premium is paid through a contract with a flour milling company. Sunshine was developed with a modified-bulk breeding method from the cross KS01HW152-6/HV9W02-267W made in 2005 at Fort Collins, CO. Following two generations (F₂ and F₃) of bulk-population evaluation, Sunshine was selected as an F₃:₄ line in July 2009, assigned experimental line number CO09W293, and evaluated in replicated yield trials from 2012 to 2014 in eastern Colorado.
6 citations