Function of complex haustoria in mistletoes
Abstract
Some mistletoe species, in particular in the Loranthaceae, develop a complex haustorial system of epicortical roots with secondary haustoria and shoot systems. Many functional aspects, aside from the obvious mechanical fixation and vegetative propagation, have not been studied in any detail. By source sink manipulation, i.e. severing of epicortical roots and host branches as well as partial removal of mistletoe and host foliage and subsequent study of the parasite's growth respons and mineral nutrient partitioning we expect to be able to answer the following questions. (1) is the secondary haustorial system a response to loss of functioning of the primary system, (2) is the secondary haustorial system influenced by host species and environmental factors, (3) is there a feedback of source capacity (cross section of the supporting host branch) on the haustorial system. The mistletoe in this project will be Scurulla parasitica growing on Rhododendron arboreum and other hosts in Nepal. Nepal was chosen because of its very steep environmental gradients, the availability of field helpers (tree climbers) at very modest rates and, last not least, the interest of Mr. Mohan Devkota, lecturer at Amrit Science College, Kathmandu, who is experienced in field work in Nepal and has a good knowledge of the native flora. A better understanding of the biology of mistletoes is of interest to conservation, because mistletoes are absolutely dependent on their endangered tree hosts. In cases where mistletoes have become pest in orchard or tree plantations, control could be improved by a better understanding of the parasite's biology. As a spin off the mistletoe flora of the Annapurna Conservation Area will be documented.
keywords haustoria mistletoe Scurulla parasitica Rhododendron arboreum
Publikationen
Project staff
Gerhard Glatzel
Em.O.Univ.Prof. Dipl.-Ing. Dr.nat.techn. Gerhard Glatzel
gerhard.glatzel@boku.ac.at
Project Leader
15.08.2000 - 15.01.2003
BOKU partners
External partners
Tribhuvan University
none
partner