Postproduction of potted miniature rose: flower respiration and single flower longevity

Research was conducted to investigate the relationship between flower respiration and flower longevity as well as to assess the possibility of using miniature rose (Rosa hybrida L.) flower respiration as an indicator of potential flower longevity. Using several miniature rose cultivars as a source of variation, four experiments were conducted throughout the year to study flower respiration and flower longevity under interior conditions. For plants under greenhouse as well as interior conditions, flower respiration was assessed on one flower per plant, from end-of-production (sepals beginning to separate) up to 8 days after anthesis. Interior conditions were 21 ± 1 °C and 50 ± 5% relative humidity with a 12-hour photoperiod of 12 μmol.m–2.s–1 (photosynthetically active radiation). Flower respiration was higher if the plants were produced during spring/summer as compared to fall/winter. ‘Meidanclar’, ‘Schobitet’, and ‘Meilarco’ miniature roses had higher flower respiration rates than ‘Meijikatar’ and ‘Meirutral’. These two cultivars with the lowest respiration rates showed much greater flower longevity if grown during spring/summer as compared to fall/winter. The three cultivars with the higher respiration rates did not show differences in flower longevity between seasons. For plants under greenhouse or interior conditions, flower respiration was negatively correlated with longevity in spring/summer but a positive correlation between these parameters was found in fall/winter. During spring/summer, flower respiration rate appears to be a good indicator of potential metabolic rate, and flowers with low respiration rates last longer.American Floral Endowment and Junta de Investigação Científica e Tecnológica (Programa Ciência, Portugal). Yodder Brothers (Parrish, Florida, U.S.A.) ofereceu as plantas