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characterization of SOC1 -like genes in woody plants is required to facilitate the breeding of woody plants. Mei, a rosaceous woody perennial tree, has been cultivated in China and other east Asian countries for over 3000 years for its ornamental and economic

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Flower color is an important characteristic of ornamental plants that results from substances in the petal cells, such as flavonoids, carotenoids, and alkaloids; and various intracellular environmental factors such as the pH value and metal ion

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Soltis, 2012 ). Genome size variation can also be used by plant breeders to identify parents for wide hybrids among parent taxa. Interspecific hybrids have been shown to have genome sizes intermediate between their parents in other woody ornamentals such

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1 Former graduate student. Current address: Univ. of Tennessee, Dept. of Ornamental Horticulture and Landscape Design, Knoxville, TN 37901-1071. 2 Professor. This research was supported in part by the Paul Ecke Poinsettia Ranch.

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Composition of capitula and their making by florets of zinnia (Zinnia violacea Cav.) were analyzed to improve seed production. For each cultivar, mature capitula were classified into three types based on shape. A capitulum was made of the accumulation of <20 newly opened florets per day for >15 days. The total number of florets per capitulum was 210 to 330, 220 to 290, and 160 to 240 for the two pumila double cultivars Kumamotonokagayaki and Snowball and for the pompon cultivar Purple Zem, respectively. The numbers of tubular florets were negatively correlated with the numbers of ray florets. Ornamentally superior capitula, which were the basic capitulum types for pumila doubles and pompons, had more ray florets and fewer tubular florets than the ornamentally inferior capitulum (the single-flowered type). Results indicate that maintaining a high percentage of plants with double-flowered capitula may decrease seed yield.

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Narrow-sense heritabilities and genetic correlations of ornamental quality traits of Antirrhinum majus (snapdragon) were evaluated with special reference to cut flower postharvest longevity (PHL). Inbreds P1 (16 days PHL) and P2 (3 days PHL) were hybridized to produce an F1 (P1 × P2) that was self-pollinated to produce an F2 population. The F2 were self-pollinated to produce F3 families and advanced through single-seed descent by self-pollination to the F5 generation. P1, P2, F1, F3, F4, and F5 were evaluated for ornamental quality traits. Quality traits were found to be quantitative and normally distributed. Narrow-sense heritability (h2) estimates were high and consistent across generations examined; PHL h2 ranged from 0.79 to 0.81 ± 0.06. Phenotypic and genotypic correlations revealed underlying physiological and pleiotropic interactions relevant to breeding programs aimed at simultaneous improvement of ornamental quality traits. PHL is inversely related to cut flower strength and days to flower, -0.44 ± 0.04 and -0.43 ± 0.44. Buds at discard is positively correlated to cut flower and plant diameter, cut flower weight and days to flower, 0.77 ± 0.05, 0.58 ± 0.06, 0.71 ± 0.06, and 0.77 ± 0.07, respectively. Gain from selection for quality traits of interest can be rapid.

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1 To whom reprint requests should be addressed at Dept. of Ornamentals, Danish Institute of Agricultural Sciences, Kirstinebjergvej 10, 5792 Aarslev, Denmark; e-mail cwh@afp.sp.dk . This research was conducted at The Pennsylvania State University

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1 To whom reprint requests should be addressed. E-mail: ariseman@interchange.ubc.ca The authors would like to thank the H.R Eddie Ornamental Plant Foundation for their financial support. We would also like to thank Drs. Iain Taylor and David Clark

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1 Present address: Vegetable and Ornamental Plant Research Institute, Private Bag X293, Pretoria, 0001, South Africa. Supported by a research grant from the South African Nature Foundation to G.J. The cost of publishing this paper was defrayed in

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A significant pest affecting commonly planted Betula spp. is the birch leafminer (Fenusa pusilla Lepeletier), an insect that can be present in large populations in the landscape and can greatly reduce the vigor and ornamental value of these trees. Twenty-two interspecific crosses were performed between leafminer resistant and susceptible Betula species in an attempt to create the novel combination of ornamental white bark and significant leafminer resistance. Of the nine successful crosses, two produced resistant offspring. Progeny of the diploid × hexaploid cross B. turkestanica Litvin (2x) × B. alleghaniensis Britt. (6x) displayed a broad range of resistance levels, likely the result of segregating alleles contributed by the hexaploid parent. All crosses involving highly resistant individuals of B. costata Trautv. (2x) yielded leafminer susceptible progeny. These results suggest that the larval antibiosis demonstrated by B. alleghaniensis and B. costata is inherited as a recessive trait, and exhibits a gene dosage effect as evidenced by the B. turkestanica × B. alleghaniensis offspring. While most progeny of the B. populifolia Marsh (2x) × B. maximowicziana Regal (2x) cross were susceptible, a single resistant offspring, which was found to be triploid (3x), displayed a mechanism of resistance similar to that of a hypersensitive response. No strong intersectional barriers to hybridization were observed and all interploidy crosses were successful. The chromosome numbers of B. costata (2n = 2x = 28) and B. turkestanica (2n = 2x = 28) are reported here for the first time. The results of this study indicate that the potential exists for the development of insect resistant, ornamental white-barked birch clones through the implementation of a planned, systematic breeding program.

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