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Brent K. Harbaugh, John W. Scott, and David B. Rubino

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Richard O. Kelly, Zhanao Deng, and Brent K. Harbaugh

Florida is one of the top wholesale producers of bedding plants, and in 2003 was ranked fourth in the United States in annual bedding plant production and fifth in potted pansy (Viola ×wittrockiana) and viola (V. cornuta) production. Evaluation of viola cultivars is vital for continued growth of the industry. We evaluated 66 viola cultivars in replicated class tests at the University of Florida's Gulf Coast Research and Education Center at Bradenton from 2000-04 and determined the best-of-class for use in future trials to compare against new entries in the same class. In this report, we provide objective plant measurements of vegetative and floral characteristics as well as subjective performance ratings. Viola cultivars were grouped into classes based on growth habit (standard vs. creeping), flower color, and flower color pattern, and the best cultivar in each class was determined. Cultivars with an outstanding overall performance rating (combined foliage, flower, arthropod feeding symptom, and disease symptom ratings ≥5.5 out of a 7 high scale) for best-of-class selections were: (standard black class) `Sorbet Black Delight'; (standard cream class) `Velour Cream Splash'; (standard mix class) `Babyface Mixture'; (standard orange with purple, red-violet cap class) `Penny Orange Jump-Up'; [standard purple (dark), blue-violet with dark eye and light cap class] `Angel Violet Blotch'; (standard white class) `Penny White'; [standard white face with purple (dark), red-violet cap class] `Skippy White With Violet Wing'; (standard yellow class) `Jewel Lemon Yellow'; (standard yellow with blotch class) `Babyface Yellow'; [standard yellow/white face with purple (dark), blue-violet cap class] `Penny Classic Jump-Up'. Solitary cultivar entries (without comparison) with outstanding performance were: `Angel Frosted Yellow Blotch', `Angel Violet Duet', `Babyface White', `Eryln Purple Yellow', `Four Seasons Yellow With Pink Wing', `Gem Antique Apricot', `Gem Antique Pink', `Gem Antique Lavender', `Hobbit Bilbo Baggins', `Jewel Deep Blue', `Penny Azure Twilight', `Penny Beaconsfield', `Penny Cream', `Penny Orange', `Penny Orchid Frost', `Penny Purple', `Penny Yellow Jump-Up', `Princess Lavender and Yellow', `Princess Purple and Gold', `Rebel Yellow', `Sorbet Coconut Swirl', `Sorbet Icy Blue', `Sorbet Lemon Swirl', `Sparkler Purple Orange Face', and `Sparkler Purple Wing'. These cultivars would likely perform well in the southern U.S. or areas of the world with similar heat and cold hardiness zones.

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Zhanao Deng, Brent K. Harbaugh, and Natalia A. Peres

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Zhanao Deng, Fahrettin Goktepe, Brent K. Harbaugh, and Jinguo Hu

Caladium (Caladium ×hortulanum Birdsey) is an important aroid widely used in the ornamental plant industry. Concerns have been raised about possible loss of genetic diversity due to a drastic decline in the number of cultivars in the last century. This study assessed genetic diversity and relationships among caladium cultivars and species accessions. Forty-five major cultivars and 14 species accessions were analyzed based on 297 DNA fragments produced by the target-region amplification polymorphism marker system. A low level of diversity (44.4% polymorphism) was exhibited in cultivars, while a high level of diversity (96.8% polymorphism) was present among seven accessions of Caladium bicolor (Aiton) Vent., Caladium marmoratum Mathieu, Caladium picturatum C. Koch, and Caladium schomburgkii Schott. A small percentage (7.6%) of DNA fragments was present in cultivars but absent in the seven species accessions, while a high percentage (32.2%) of DNA fragments was present in the seven species accessions but absent in cultivars. Cultivars shared a higher level of similarity at the molecular level with an average Jaccard coefficient at 0.802, formed a large group in cluster analysis, and concentrated in the scatter plot from a principal-coordinate analysis. Two accessions of C. bicolor and C. schomburgkii were very similar to cultivars with Jaccard similarity coefficients from 0.531 to 0.771, while the rest of the species accessions had small similarity coefficients with cultivars (0.060 to 0.386). Caladium steudnirifolium Engler and Caladium lindenii (André) Madison were very dissimilar to C. bicolor, C. marmoratum, C. picturatum, and C. schomburgkii, with Jaccard similarity coefficients from 0.149 to 0.237 (C. steudnirifolium) and from 0.060 to 0.118 (C. lindenii). There is a limited amount of molecular diversity in caladium cultivars, but the great repertoire of unique genes in species accessions could be used to enhance the diversity in future cultivars and reduce potential genetic vulnerability.

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Zhanao Deng, Brent K. Harbaugh, and Natalia A. Peres

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Brent K. Harbaugh, John W. Scott, and David B. Rubino

Seedlings of commercial lisianthus cultivars form rosettes when grown at 25 to 28°C. Rosetted plants have a basal cluster of leaves, very short internodes typical of biennials, and do not bolt or flower for months without being exposed to 3 to 4 weeks at <15 to 18°C to reverse heat-induced rosetting. Semirosetted plants develop when seedlings are grown at a constant 22 to 25°C or at <22°C night with >28°C day. Semirosetted plants have one or more side shoots which may elongate and flower, but plants flower unpredictably and are of poor quality as cut flowers or potted plants. `Maurine Blue' and Florida Blue' were released from the Univ. of Florida in 1995. To our knowledge, they are the first heat-tolerant lisianthus cultivars. Seedlings and plants can be grown at 28 to 31°C without rosetting. `Maurine Blue' ranged in height from 38 cm (summer) to 67 cm (spring) during 1994 and 1995 production trials in Florida. `Maurine Blue' has potential for use as a tall bedding plant if sold as green transplants, a flowering potted plant if grown with three plants per 15-cm-diameter pot with a growth retardant, or as a bouquet-type cut flower. `Florida Blue' plants (38 cm) grown in an 11.5-cm square pot (0.65-L) with capillary mat irrigation were similar in height to `Blue Lisa' (32 cm) and taller than `Little Belle Blue' (22 cm) and `Mermaid Blue' (24 cm). `Florida Blue' was designated as a semi-dwarf cultivar with an intended use as a bedding plant. Growth retardants would be useful for production in pots <10 to 12 cm in diameter. Complete descriptive information, photographs and pedigrees will be presented.

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Brent K. Harbaugh, B.D. Miranda, and G.J. Wilfret

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Brent K. Harbaugh, Michelle L. Bell, and Rongna Liang

Lisianthus [Eustoma grandiflorum (Raf). Shinn.] is emerging as an important cut flower in the United States while in European and Asian markets it is already listed among the top ten cut flowers. Many new cultivars have been released in the United States within the last 5 years, but comparative performance trials of these cultivars have been lacking. This trial evaluated 47 cultivars of lisianthus representing series (cultivar groups) that were marketed in the United States in 1998. Evaluations were made for rosetting, plug performance, cut-flower characteristics (vegetative and flowering attributes) as well as postharvest longevity of cut flowers. Significant differences among cultivars were found for all of the attributes evaluated. `Malibu Purple', `Catalina Blue Blush', and `Alice Pink' were selected as the best performers in the seedling (plug) stage since they had less than 5% rosettes, large leaves and a vigorous root system. Cultivars were placed in classes based on flower color, flower size, and number of petals (single or double flowers). Cultivars were ranked for each of the attributes and the total rank sum of all attributes (TRS) was used to select the best in class. Cultivars selected as best in class were `Malibu Purple', `Malibu Blue Blush', `Alice Purple', `Balboa Blue', `Avila Blue Rim', `Mellow Pink', `Flamenco Wine Red', `Flamenco Rose Rim', `Alice Pink', `Avila Rose' and `Echo Pink', `Alice White', and `Mariachi White'.

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Richard O. Kelly, Zhanao Deng, and Brent K. Harbaugh

Central Florida has a climate similar to many locations in the southeastern United States and parts of Asia, Europe, and Australia. Thus, Florida is an important testing ground for new bedding plant cultivars not only in the United States, but around the world. The authors evaluated 125 petunia (Petunia ×hybrida) cultivars in replicated class tests at Bradenton, Fla. (lat. 27º4′N, long. 82º5′W) in 2000–04 and at Balm, Fla. (lat. 27º8′N, long. 82º2′W) in 2005–06. In this report they establish petunia classes and cultivar standards for each class, and provide objective plant measurements of vegetative and floral characteristics, and subjective performance ratings. Petunia cultivars were grouped into 73 classes based on the distinguishing characteristics for petunia, which are plant type and height, and flower type, color, and color pattern. Comparisons were made within each class to determine performance and to select a cultivar as the standard for the class—a plant with the highest overall performance rating that can represent the class in future trials against new cultivars. During the initial trials, larger numbers of cultivars were evaluated and eliminated from future comparisons when each class standard was selected. Many flower colors and color combinations, as well as plant types and other distinctive characteristics have been developed for bedding plants. By creating class standards for each distinctive characteristic, better choices over a wider range of classes are available to growers and landscapers in this climate. Cultivars with an outstanding overall performance rating (combined foliage, flower, arthropod feeding symptom, and disease symptom ratings ≥5.5 points on a 1 to 7-point scale) for class standard selections were (floribunda, single mix class) ‘Madness Waterfall Mix’ and [single purple (dark), red-violet class] ‘Madness Magenta’; [grandiflora, single blue (dark) class] ‘Eagle Blue’, (single orange shades/tints class) ‘Ultra Salmon’, and [single purple (dark), red-violet class] ‘Storm Violet’; and [spreading, normal, orange (dark) shades/tints class] ‘Ramblin’ Salmon Capri’, [orange (light) shades/tints class] ‘Ramblin’ Peach Glo’, [pink (dark) class] ‘Wave Pink’, [purple (dark), blue-violet class] ‘Avalanche Lavender’, [purple (light) blue-violet class] ‘Ramblin’ Lavender’, (red class) ‘Avalanche Red Improved’, (rose class) ‘Avalanche Rose Improved’, (white class) ‘Plush White’, and [spreading, tall; blue (dark) class] ‘Wave Blue’. These cultivars would likely perform well in the southern United States or areas of the world with similar heat and cold hardiness zones.

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Zhanao Deng, Brent K. Harbaugh, and Natalia A. Peres