Changes in respiration, protein and carbohydrates of tulip tepals and Alstroemeria petals during development

Respiration, fresh and dry mass, protein and carbohydrate concentrations were measured in tulip tepals and Alstroemeria petals during expansion and senescence. Tepal and petal dry-mass increased to maximum values by the rime the flowers were fully opened and then decreased during senescence. Fresh-mass increases were proportional co dry-mass increases during the early stages of development, but were more rapid as the tissues matured. In both tepals and petals, a large, rapid increase in respiration per unit dry-mass was observed prior to flower opening and complete biomass accumulation. Respiration had decreased 23 and 30 %, in tepals and petals, respectively, by the rime che flower had fully opened. Respiration per unit protein also increased, but the maximum rate in both species occurred when the flower was fully opened. Respiration decreased during senescence. Protein concentration in tepals increased and then decreased during development, while protein decreased in petals. Glucose, the dominant carbohydrate in tepals, decreased during development. Starch was the dominant carbohydrate in petals and decreased in association with increased glucose and fructose concentrations. Mass-based respiration was positively correlated with absolute growth rate and protein concentration in developing tepals, bur no correlations were observed in Alstroemeria petals.