| 1 | RosBREED:bridging the chasm between discovery and application to enable DNA-informed breeding in rosaceous crops显示文摘The Rosaceae crop family(including almond,apple,apricot,blackberry,peach,pear,plum,raspberry,rose,strawberry,sweet cherry,and sour cherry)provides vital contributions to human well-being and is economically significant across the U.S.In 2003,industry stakeholder initiatives prioritized the utilization of genomics,genetics,and breeding to develop new cultivars exhibiting both disease resistance and superior horticultural quality.However,rosaceous crop breeders lacked certain knowledge and tools to fully implement DNA-informed breeding—a“chasm”existed between existing genomics and genetic information and the application of this knowledge in breeding.The RosBREED project(“Ros”signifying a Rosaceae genomics,genetics,and breeding community initiative,and“BREED”,indicating the core focus on breeding programs),addressed this challenge through a comprehensive and coordinated 10-year effort funded by the USDA-NIFA Specialty Crop Research Initiative.RosBREED was designed to enable the routine application of modern genomics and genetics technologies in U.S.rosaceous crop breeding programs,thereby enhancing their efficiency and effectiveness in delivering cultivars with producer-required disease resistances and market-essential horticultural quality.This review presents a synopsis of the approach,deliverables,and impacts of RosBREED,highlighting synergistic global collaborations and future needs.Enabling technologies and tools developed are described,including genome-wide scanning platforms and DNA diagnostic tests.Examples of DNA-informed breeding use by project participants are presented for all breeding stages,including pre-breeding for disease resistance,parental and seedling selection,and elite selection advancement.The chasm is now bridged,accelerating rosaceous crop genetic improvement. | Amy F.Iezzoni Jim McFerson James Luby Ksenija Gasic Vance Whitaker Nahla Bassil Chengyan Yue Karina Gallardo Vicki McCracken Michael Coe Craig Hardner Jason D.Zurn Stan Hokanson Eric van de Weg Sook Jung Dorrie Main Cassia da Silva Linge Stijn Vanderzande Thomas M.Davis Lise L.Mahoney Chad Finn Cameron Peace | 2020 | Horticulture Research2020，7，1： | 2 |
| 2 | A pentaploid-based linkage map of the ancestral octoploid strawberry Fragaria virginiana reveals instances of sporadic hyper-recombination显示文摘The first high-resolution genetic linkage map of the ancestral octoploid(2n=8x=56)strawberry species,Fragaria virginiana,was constructed using segregation data obtained from a pentaploid progeny population.This novel mapping population of size 178 was generated by crossing highly heterozygous F.virginiana hybrid“LB48”as a paternal parent with diploid(2n=2x=14)Fragaria vesca“Hawaii 4”.The LB48 linkage map comprises 6055 markers genotyped on the Axiom®IStraw90 strawberry SNP array.The map consists of 28 linkage groups(LGs)organized into seven homoeology groups of four LGs each,and excludes a small 29th LG of undefined homoeology.One member of each homoeology group was assignable to an“A”subgenome associated with ancestral diploid Fragaria vesca,while no other subgenomes were defined.Despite an intriguing discrepancy within homoeology group VI,synteny comparisons with the previously published Fragaria×ananassa DA×MO linkage map revealed substantial agreement.Following initial map construction,examination of crossover distributions revealed that six of the total 5162(=29 chromosomes/individual×178 individuals)chromosomes making up the data set exhibited abnormally high crossover counts,ranging from 15 to 48 crossovers per chromosome,as compared with the overall mean of 0.66 crossovers per chromosome.Each of these six hyper-recombinant(HypR)chromosomes occurred in a different LG and in a different individual.When calculated upon exclusion of the six HypR chromosomes,the canonical(i.e.,broadly representative)LB48 map had 1851 loci distributed over a total map length of 1873 cM,while their inclusion increased the number of loci by 130,and the overall map length by 91 cM.Discovery of these hyper-recombinant chromosomes points to the existence of a sporadically acting mechanism that,if identified and manipulable,could be usefully harnessed for multiple purposes by geneticists and breeders. | Thomas M.Davis Yilong Yang Lise L.Mahoney Daniel C.Frailey | 2020 | Horticulture Research2020，7，1： | 1 |
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