. The objectives of this research were to 1) determine the effects of osmotic treatment for enhancing water deficit tolerance in viola, and 2) identify the relationship between stomatal closure and water loss under water deficit in CaCl 2 -treated violas
( Warrington and Norton, 1991 ). Petunia grown under a higher DLI had more and larger flowers ( Kaczperski et al., 1991 ). In addition, an elevated DLI inhibited stem and peduncle extension growth in pansy ( Viola × wittrockiana Gams.) ( Niu et al., 2000
habits ( De, 2017 ). Commercially available pansies are F 1 hybrids produced by hand crossing. Currently, such production of Viola tricolor maxima with hermaphrodite flowers requiring emasculation occasionally occurs at the expense of limited
determine how to prevent s-ABA-induced leaf chlorosis in pansy and viola. Although s-ABA applications allow pansies to survive temporary periods of drought stress, negative side effects like leaf chlorosis decrease overall crop quality ( Waterland et al
Viola is a popular bedding plant. The relatively high initial cost of flower seeds has led growers to use precision seeding and transplant production systems to maximize seedling stands ( McDonald and Kwong, 2005 ). Maximum efficiency in plug
The seed producing system in viola (Viola ×cornuta) was investigated to improve seed yield and to save labor. In a flower five anthers sequentially dehisced; pollen grains were continuously supplied to the anterior petal, which played a significant role in pollination, throughout the flowering period. Evidence from pollen and ovule number suggests that the species is facultative autogamy. Each flower opened more than 10 days was independent of the success in fertilization and kept seed producing ability during the flower longevity period. Pollen grains also maintained viability during the flower longevity period. Pollinators were indispensable for pollination of viola, but pollination in viola was done by a different mechanism from the typical insect-mediated pollination that sticky pollen grains adhere to the exposed stigmas. Pollen grains, accumulated around the entrance of the stigmatic cavity, entered into the cavity by the movement of pollinators. Although the visitation of pollinators was occasional, solitary bees primarily contributed to the pollination of viola. On the other hand, germination of pollen grains on the stigmatic surface was under 50%. Seed set was much lower than the germination percentage of pollen grains. A viola flower had the ability for additional pollinations and fertilization for some days after the fertilization success in some ovules in the flower. This characteristic suggested that repeated pollination is effective to increase the number of mature seeds in a capsule.
.J. Jones, M.L. 2010b Benzyladenine and gibberellic acid application prevents abscisic acid-induced leaf chlorosis in pansy and viola HortScience 45 925 933 Weaver, G.M. van Iersel, M.W. 2014 Reducing transpiration of pansies ( Viola ×wittrockiana ) with
The pansy, Viola tricolor Hortensis, L. is a popular bedding plant, however, the problem of low seed set has hindered genetic studies, plant breeding efforts, and the production of Fl hybrids. Twenty-nine commercial inbred pansy lines were investigated cytologically to establish a possible relationship between chromosome number and pollen fertility. The somatic chromosome number of all lines studied was found to be 2n=48 and pollen fertility was above 90 percent. Preliminary hybridization investigations suggest the problem may be an incompatibility system.
Viola × wittrockiana Gams. cvs `Delta Pure Rose' and `Sorbet Yellow Frost' were grown under different photoperiod and temperature treatments (12–24 ± 2°C) for different lengths of time at different stages of development during the first 6 weeks after germination. Plants were grown with ambient light (≈9 hr) at 16°C before and after treatments. Days to anthesis and leaf number were lowest when plants were grown under night interruption from 2200–0200 hr (2 μmol·m–2·s–1 from incandescent lamps) and daylight plus continuous light (100 μmol·m–2·s–1 from high-pressure sodium lamps) for `Sorbet Yellow Frost' and `Delta Pure Rose', respectively. Days to anthesis decreased as temperature increased from 12 to 24°C. Plant height and internode elongation were greatest and least in the night interruption and continuous light treatments, respectively. Branching decreased as temperature increased from 12 to 24°C. Implications of these data with respect to classification of Viola × wittrockiana flower induction and development of prefinished seedlings is discussed.
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.