Postharvest flower development in Asiatic hybrid lilies as related to tepal carbohydrate status

For three Asiatic hybrid lily cultivars ('Bright Beauty', 'Fashion', 'Orlito') the potential postharvest performance of floral buds in terms of growth, anthesis and longevity was studied in relation to tepal carbohydrate status. To determine the importance of carbohydrate redistribution within lily inflorescences, the postharvest performance of several attached and detached buds was compared at the time of anthesis of the most mature floral bud of the inflorescence. Detachment of buds increased failure of opening in small buds, whereas in the largest buds tepal size at anthesis and longevity were improved. In lily inflorescences, postharvest translocation of substrate from the basal to the upper buds takes place. Five bud classes have been characterised, comparing the postharvest performance of attached and detached buds. Classes were based on differences in tepal growth rate, absolute growth and the potential to reach anthesis. A bud length of about 60 mm at harvest, appeared to be critical for reaching anthesis of detached buds. Comparable bud development and flower longevity of inflorescence-attached and inflorescence-detached floral buds was determined in buds of 70-75 mm. At this bud length the total carbohydrate content (fructose, glucose, glycerol glucoside, starch, sucrose) covered about three-fourths of the total tepal carbohydrate content found in the largest bud stage just prior to anthesis. Per cultivar, postharvest flower longevity after anthesis of detached buds was well correlated with total carbohydrate content of the tepals at harvest. Longevity of inflorescence-attached flowers remained constant within the inflorescence, likely due to postharvest redistribution of tepal carbohydrate. These findings indicate an important role for tepal carbohydrate content in postharvest bud development and flower longevity of Asiatic hybrid lilies. Carbohydrate redistribution is suggested to play a major role in the postharvest performance of Asiatic lily inflorescences. (C) 2001 Elsevier Science B.V. All rights reserved.