Seasonal variations of sulphur, phosphorus and magnesium in the leaves and current-year twigs of hemiparasitic mistletoe Loranthus europaeus Jacq. and its host Quercus pubescens Willd.

Abstract

The objectives of this research were to investigate nutrient seasonal dynamics in the hemiparasitic mistletoe Loranthus europaeus von Jacquin and its host Quercus pubescens Willdenow, and to evaluate nutrient relationships between mistletoe and its host. For these purposes, S, P and Mg concentrations in the leaves and current-year twigs were analysed 12 times during the growing season. We found that the studied nutrients were not retrieved from hemiparasitic mistletoe leaves prior to abscission, contrary to its host. The seasonal dynamics of S, P, and Mg in L. europaeus and Q. pubescens leaves differed from each other while in current-year twigs the dynamics was similar in both species. In general, nutrient concentrations in the leaves and current-year twigs were higher in mistletoe compared with its host. But the mistletoe to host nutrient ratios varied greatly during the growing season, especially in leaves, mostly during leaf expansion and senescence. Thus, studies investigating nutrient relationships between mistletoe and its host should be realized during the period of leaf maturity.

Keywords

• active transport
• leaf development
• mistletoe-host interaction
• nutrient relationships
• nutrient remobilization
• passive transport