Short communication Use of various carbon sources by isolated maple callus cultures *

The growth of isolated maple cellus (A. rubnan and A. sacckarum) indicated 4 general categories for the use of carbon sources: lactose, melibiose, mannose, maltose-minimal growth; fructose, galactose-limited growth; trehalose, cellobiose, raffinose, glucose, sucrose—good growth. The results also indicated that tissues grew as well on medium containing filter-sterilized sugars as on medium containing autoclaved sugars. Researchers have investigated the relative growth of isolated callus tissues on media containing various carbon sources (1, 2). Most investigators agree that sucrose provides the best energy source for a wide range of isolated tissues. Sucrose has however been reported to be more effective after autoclaving in different media (3-5). Ball (3) pointed out that this may not be a sucrose effect since one third of the sugar present was hydrolyzed to constituent hexoses after autoclaving. An increase in growth, above that obtained in the presence of filter-sterilized sucrose, has been suggested (6) to be the result of autoclaving sucrose in the presence of agar. This investigation reports the ability of selected autoclaved and filter-sterilized carbon sources to support the growth of isolated maple callus culture