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Öğe Genotype by environment interactions and combining ability for strawberry families grown in diverse environments(Springer, 2017) Mathey, Megan M.; Mookerjee, Sonali; Mahoney, Lise L.; Gunduz, Kazim; Rosyara, Umesh; Hancock, James F.; Stewart, Philip J.Ten seedlings from 36 crosses representing eastern and western North American short day and remontant genotypes were evaluated in 2011 and 2012 in California, Michigan, New Hampshire and Oregon, for phenology, flower related traits, plant characteristics, fruit characteristics and fruit chemistry traits. There was significant variability among genotypes, locations and evaluation year for most of the characteristics; however, few genotype 9 location and genotype 9 year interactions were detected. General combining ability variance components were significant for all traits and greater than SCA variance components for peduncle length, total flowering weeks, flowering cycles, truss size, growing degree days for harvest data, remontancy, achene position, ease of capping, fruit weight, percent soluble solids, titratable acidity and soluble solids/titratable acidity. `Sarian' was identified as the best contributing parent for remontancy. Narrow-sense heritability estimates were moderate to high (0.33-0.78) for total flowering weeks, flowering cycle, truss size, remontancy, number of runners, fruit weight, pH, and titratable acidity. Having a better understanding of these attributes will provide breeders guidance on the most effective breeding strategies for incorporating superior traits from this germplasm into their programs.Öğe Inheritance of day-neutrality in octoploid species of Fragaria(American Society for Horticultural Science, 2005) Serçe, Sedat; Hancock, James F.The inheritance of day-neutrality in octoploid Fragaria L. was investigated in crosses between day-neutral (DN) x short day (SD) and DN x DN types using F. xananassa Duchesne in Lamarck cultivars and elite selections of F. virginiana Miller and F. chiloensis (L.) Miller. Genotypes were considered as DN if they flowered under both the SDs of spring before 30 May (<14 hours) and the long days of summer after 24 July (>15 hours). Wide ranges in the percentage of DN progeny were found among the families regardless of species background (30 % to 87 % in DN x SD and 22% to 93% in DN x DN crosses). None of the families fit the segregation ratios expected if DN was regulated by recessive alleles at one locus, and only about half of the families fit the segregation ratios expected if a single dominant allele regulated DN. Several two-gene models fit the segregation data better than the single locus ones, but none of the genetic models tested fit the DN segregation ratios at the ends of the distribution range. The wide range observed in the percentage of DN progeny across all the families is most consistent with a polygenic model. Several other kinds of observations supported the multigenic regulation of DN: 1) Different DN parents crossed to the same SD genotype often produced different percentages of DN progeny, 2) Some of the day-neutrality sources were more powerful than others in producing of DNs, and 3) None of the DN parents produced 100% DN progeny, which would be expected if there were homozygous dominant DN individuals. Specific combining abilities for DN and flowering strength were significant, while general combining abilities for these traits were not. Our results suggest that parental combinations can be selected that will generate very high proportions of DN progeny that bloom for long periods of time.Öğe Phenotypic variability in a panel of strawberry cultivars from North America and the European Union(Amer Pomological Soc, 2015) Hancock, James F.; Callow, Peter W.; Mathey, Megan M.; Mackey, Ted; Gunduz, Kazim; Mookerjee, Sonali; Cai, LichunThe phenotypic diversity in 96 antique and modern strawberry cultivars from the European Union and North America was evaluated in Michigan and Oregon, in 2011 and 2012. A total of thirty-five fruit and developmental characteristics were measured. Significant differences (p < 0.05) were observed among cultivars and environment for most of the characteristics, although only a few significant genotype x environment interactions were found. Several cultivars were superior for multiple traits including 'Aromas' from California (size, glossiness, crop load and weeks of flowering), 'Allstar from the Mid-Atlantic States (glossiness, firmness, drip loss and soluble solids concentration), 'Florida Radiance' (external color, skin strength, size, drip loss and acidity), 'Gorella' from the European Union (skin strength, internal color and soluble solids concentration) and 'Melody' from the European Union (external color, skin strength and drip loss). No antique cultivars carried superior traits that were not found in modem cultivars. The data in these trials will be combined with DNA diagnostic tests to identify genes of importance for strawberry breeding.Öğe Reconstructing Fragaria x ananassa utilizing wild F-virginiana and F-chiloensis(Springer, 2008) Luby, James J.; Hancock, James F.; Dale, Adam; Serce, SedatThe genetics of disease resistance, winter hardiness, spring bloom date, fruit set, ovule set, fruit size, and photoperiod sensitivity was investigated in crosses between sets of elite selections of F. virginiana and F. chiloensis in Minnesota and Ontario. In Minnesota, family means varied considerably for all traits except ovule set. For all other traits, general combining ability was significant for at least one species, while specific combining ability was significant for only spring bloom date. In Ontario, general combining ability was significant for all traits in at least one species except flower number. Just as they were in previous crosses with F. x ananassa cultivars, the F. virginiana parents High Falls 22 and Montreal River 10 were notable for producing offspring with large fruit and high fertility. Fragaria chiloensis parents exhibited strong combining ability effects for short day-induced flowering and suppressed the expression of day-neutral flowering in these progeny compared to progeny of these F. virginiana in previous crosses with F. x ananassa. These results indicate that substantial breeding progress can be made by reconstructing F. x ananassa if care is taken to select elite, complementary genotypes of F. virginiana and F. chiloensis.Öğe Reconstruction of the Strawberry, Fragaria xananassa, Using Genotypes of F. virginiana and F. chiloensis(Amer Soc Horticultural Science, 2010) Hancock, James F.; Finn, Chad E.; Luby, James J.; Dale, Adam; Callow, Pete W.; Serce, SedatThe germplasm base of strawberries is restricted. The major cultivated strawberry species, Fragaria xananassa, originated approximate to 250 years ago when South American F. chiloensis subsp. chiloensis forma chiloensis and North American F. virginiana subsp. virginiana accidentally hybridized in European gardens. Since that time, only a handful of native clones have been used by breeders. As a novel way to expand the germplasm base of the strawberry, we preselected native clones of F. virginiana and F. chiloensis for a wide range of horticulturally important characteristics and then reconstructed F. xananassa by crossing superior clones of each. Before crossing between species, we undertook one round of selection within species to maximize diversity. Reconstruction appeared to be an effective method of strawberry improvement, because superior families and individuals were identified that had outstanding vigor, high productivity, seed set, fruit color, and firmness. None of the fruit were of commercial size, but one reconstruction family, FVC 11 [(F. virginiana Frederick 9 x LH 50-4) x (F. chiloensis Scotts Creek x 2 MAR 1A)], had individuals with fruit weights of almost 20 g.Öğe Reconstruction of the strawberry, fragaria ×ananassa, using genotypes of F. virginiana and F. chiloensis(American Society for Horticultural Science, 2010) Hancock, James F.; Finn, Chad E.; Luby, James J.; Dale, Adam; Callow, Pete W.; Serçe, SedatThe germplasm base of strawberries is restricted. The major cultivated strawberry species, Fragaria ×ananassa, originated ?250 years ago when South American F. chiloensis subsp. chiloensis forma chiloensis and North American F. virginiana subsp. virginiana accidentally hybridized in European gardens. Since that time, only a handful of native clones have been used by breeders. As a novel way to expand the germplasm base of the strawberry, we preselected native clones of F. virginiana and F. chiloensis for a wide range of horticulturally important characteristics and then reconstructed F. ×ananassa by crossing superior clones of each. Before crossing between species, we undertook one round of selection within species to maximize diversity. Reconstruction appeared to be an effective method of strawberry improvement, because superior families and individuals were identified that had outstanding vigor, high productivity, seed set, fruit color, and firmness. None of the fruit were of commercial size, but one reconstruction family, FVC 11 [(F. virginiana Frederick 9 × LH 50-4) × (F. chiloensis Scotts Creek × 2 MAR 1A)], had individuals with fruit weights of almost 20 g.Öğe Usefulness of FaPFRU-Associated Perpetual Flowering Markers in the Cultivated Octoploid Strawberry(Amer Soc Horticultural Science, 2015) Salinas, Natalia; Daeil, Kim; Perrotte, Justine; Gaston, Amelia; Potier, Aline; Hancock, James F.; Gunduz, Kazim[Abstract Not Available]Öğe Validating Markers Linked to Soluble Solids Content in Octoploid Strawberry(Amer Soc Horticultural Science, 2014) Salinas-Aponte, Natalia; Hancock, James F.; Gunduz, Kazim; Denoyes, Beatrice; van de Weg, Eric; Sargent, Daniel J.; Amaya, Iraida[Abstract Not Available]Öğe Validating Microsatellite Markers Linked to Remontancy in Octoploid Strawberry(Amer Soc Horticultural Science, 2014) Salinas-Aponte, Natalia; Kim, Daeil; Hancock, James F.; Gunduz, Kazim; Denoyes, Beatrice; Perrotte, Justine; Mathey, Megan M.[Abstract Not Available]Öğe Variation among highbush and rabbiteye cultivars of blueberry for fruit quality and phytochemical characteristics(Academic Press Inc Elsevier Science, 2015) Gunduz, Kazim; Serce, Sedat; Hancock, James F.Variability in soluble solids (SS), titratable acidity (TA), SS/TA, pH, total phenolic content (TPC), ferric reducing ability of plasma (FRAP), total monomeric anthocyanin content (TMAC) and levels of vitamin C were evaluated in a broad array of northern and southern highbush (Vaccinium corymbosum) and rabbiteye (Vaccinium virgatum) cultivars of blueberry, grown in different locations and years. When cultivars were grouped by decade of release, there were few significant overall trends observed over years in fruit quality and phytochemical content; however, individual cultivars varied significantly for all the traits analysed. Considerable overlap in most quality and phytochemical characteristics were found among cultivars of the three blueberry types, suggesting that genetic barriers do not exist among the various types of blueberries with regard to breeding cultivars with comparable sugar, acid and phytochemical properties. There were significant negative correlations observed between fruit weight and SS, TPC, FRAP and TMAC, suggesting that as breeders have been selecting for larger fruit, they have inadvertantly selected for tarter fruit with lower antioxidant capacity. However, SS was correlated positively with FRAP and TMAC, indicating that cultivars can be developed that have high antioxidant capacity and anthocyanin content, combined with high sugar content. 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