Differing Vernalization Responses of Veronica spicata ‘Red Fox’ and Laurentia axillaris

Autor: Arthur C. Cameron, Beth A. Fausey
Rok vydání: 2007
Předmět:
Zdroj: Journal of the American Society for Horticultural Science. 132:751-757
ISSN: 2327-9788
0003-1062
DOI: 10.21273/jashs.132.6.751
Popis: Many polycarpic herbaceous perennials are known to have a cold-requirement for flowering. To determine the range and relative effectiveness of vernalization temperatures for flower induction, clonally propagated plants of veronica (Veronica spicata L.) 'Red Fox' and laurentia (Laurentia axillaris (Lindl.) E. Wimm.) were exposed to temperatures from -2.5 to 20 8C at 2.5 8C increments for 0, 2, 4, 6, or 8 weeks (veronica 'Red Fox') and 0, 2.5, 5, 7.5, 10, 12.5, or 15 weeks (laurentia). After treatments, growth and flowering were monitored in a glass greenhouse set at 20 8C with an average daily light integral of '5 molm -2 d -1 . Both veronica 'Red Fox' and laurentia exhibited obligate vernalization requirements for flowering, but the temperature-response curves were distinctly different. A minimum of 4 weeks at -2.5 and 0 8C, 6 weeks at 2.5 8C, and 8 weeks at 5 and 7.5 8C was required for complete (100%) flowering of veronica 'Red Fox', while a minimum of 5 weeks at 5 to 10 8C, 7.5 weeks at 12.5 8C, and 10 weeks at 2.5 8C were required for complete flowering of laurentia. For veronica 'Red Fox', node number under each flower and flower timing were relatively fixed following up to 8 weeks at each temperature, although these values generally decreased at each temperature with extended exposure for laurentia. Based on percent flowering and percentage of lateral nodes flowering, vernalization of veronica 'Red Fox' was most effective at 0 and -2.5 8C, while based on percent flowering and flower number, vernalization of laurentia was most effective at 5 to 10 8C. Many herbaceous winter annual, biennial, and perennial plants require vernalization, exposure to low temperatures, for flower induction (Chouard, 1960; Thomas and Vince-Prue, 1984). While vernalization responses of numerous plant species have been studied, the bulk of our knowledge comes from extensive research on a relatively few plant species. In particular, numerous studies have evaluated the vernalization responses of winter annuals and biennials such as winter wheat (Triticum aestivum L.), 'Petkus' winter rye (Secale cereale L.), carrot (Daucus carota L.), celery (Apium graveolens L.), sugar beet (Beta vulgaris L.), onion (Allium cepa L.), arabidopsis (Arabidopsis thaliana (L.) Heynh.) var. Stockholm, Hyoscya- mus niger (L.), and Lunaria annua (L.) (Chouard, 1960; Lang, 1952, 1965; Thomas and Vince-Prue, 1984).
Databáze: OpenAIRE
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