Rootstock-induced changes in the dry matter and carbohydrate contents of bearing shoots and flower buds in two Serbian plum cultivars

Abstract

The influence of the seedling rootstocks 'Myrobalan' and 'Stanley' on seasonal variability and the contents of dry matter (DM), starch (STA), and sugars [reducing (RS), non-reducing (NRS), and total (TS)] in bearing shoots (BS) and flower buds (FB) of 'Cacanska lepotica' and 'Cacanska najbolja' plum (Prunus domestica L.) were investigated. Regarding patterns of seasonal change, the decline in STA contents in BS and FB coincided with an increase in soluble sugars contents, and probably resulted from the conversion of starch to sugar in response to cooler temperatures. The more vigourous 'Myrobalan' rootstock induced higher STA contents in BS, and NRS contents in FB, whereas the less vigorous 'Stanley' rootstock induced higher sugars contents in BS, and DM and STA contents in FB. In contrast, 'Cacanska lepotica' had higher STA contents in FB, and sugars contents in BS, whereas 'Cacanska najbolja' had higher STA contents in BS, and NRS and TS contents in FB. The significant interactions observed between some treatments suggested that DM and carbohydrate contents in BS and FB did not depend on rootstock or cultivar, but on the combination, and on environmental conditions. Finally, BS had higher STA, NRS and TS contents, whereas FB had higher DM contents. RS contents were similar in both BS and FB.