Abstract (EN):
Pectic polymers are major components of primary cell walls having a high water-binding ability. Pectin levels and solubility were quantified in stems and petals of rose (Rosa hybrida L.), chrysanthemum (Chrysanthemum morifolium Ramat.), carnation (Dianthus caryophyllus L.), and snapdragon (Anthirrhinum majus L.) and related to the rate of solution uptake and to the rate of fresh weight increase during the vase life of these cut flowers. Total pectins in stems ranged from 176 mu g.mg(-1) in chrysanthemum to 203 mu g.mg(-1) in carnation. Water soluble pectin accounted for only 1.9 to 3.6% of total stem pectins, in rose and snapdragon, respectively, whereas chelator-soluble pectins ranged from 3.8% of total in chrysanthemum to 10.1% in snapdragon. Petals of each species had a higher proportion of water- and chelator-soluble pectins than stems. Water uptake rate during vase life was 0.16 g.g(-1).day(-1) for carnation, 0.35 g.g(-1).day(-1) for chrysanthemum, 0.52 g.g(-1).day(-1) for rose, and 0.62 g.g(-1).day(-1) for snapdragon. In the absence of salts, maximum fresh weight increase in relation to the initial value varied from 15% in carnation to 33% in chrysanthemum. Addition of KCl or CaCl(2) to the vase solution depressed the uptake rate but prolonged the period of increasing fresh weight and delayed the fresh weight decline. Significant positive linear relationships were found between the solubility of stem pectins and the rate of fresh weight increase in the four cut flowers and between the solution uptake rate and the amount of CDTA-soluble pectins present in the petals. These results provide correlative evidence for a role of pectins in the water relations of cut flowers.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
7