The work research aims to study the whole reproductive cycle of the evergreen shrub Rhododendron ferrugineum
in response to site conditions along an altitudinal gradient. For entomophilous plants, pollinators are essential for
gene dispersal and to ensure genetic diversity in the population.
As the distance and directionality of pollen travel are of crucial importance in evaluation of the pollinator`s role in
the rate of gene flows, is it possible to estimate the gene flow in closed stands of R. ferrugineum? Mating between
near neighbours could result in inbreeding depression, whereas mating between distant neighbours could disrupt
local adaptation. Therefore, is it possible to estimate the optimal outcrossing distance?
What is the pollen load on the insects visiting flowers ? (discrimination between the "total pollen load" and the
"functional pollen load") and is there a difference in nectar production between different sites?
Environmental factors influence the reproductive capacity mostly by effects on the plant`s nutrient status. With
regard to the marked differences in shoot growth, and photosynthetically active biomass between Rhododendron
stands and small shrubs; the following questions will be addressed:
In R. ferrugineum the flower buds for the following year are formed at the ends of the new shoots. When do they
become floral, how long does the flower development take, what is the number of floral meristems per shoot and
what is the proportion of anomalies in reproductive organs?
Abortions during seed development further diminish the reproductive success. Are there differences in the timing
and in the rate of abortions between the different sites in R. ferrugineum? Does the shoot growth influence the
dynamics of seed development? Since site conditions (temperature) influence the vitality of a plant, they could
indirectly affect the duration of seed development and the maturation state of the seeds in autumn as well. Are
there differences in the seed size, the state of differentiation of the embryo and the food reserves?