Pollen quality in some representatives of the genus Pinus

Abstract

During spring 2012 pollen quality of 12 pine species (P. cembra L., P. armandii Franch., P.
wallichiana A.B. Jacks., P. strobus L., P. bungeana Zucc. ex Endl., Pinus nigra J.F. Arnold,
P. sylvestris L., P. mugo Turra, P. coulteri D. Don, P. jeffreyi Balf., P. ponderosa Douglas
ex C. Lawson, P. rigida Mill.) growing in Mlyňany Arboretum was investigated. Pollen
germination was tested at 25 °C on medium consisting of 1.5% agar and 10% sucrose. Each
sample was triplicated. After 48 hours the number of germinating pollen was recorded from a
sample of 100 pollen grains, whereas the pollen tube length in a sample of 30 pollen grains of
each Petri dish. Data on average daily temperatures were taken from the local meteorological
station in Mlyňany Arboretum. In general, all the analyzed pine species showed high levels
of germination ranging from 85% in P. ponderosa to 98.89% in P. cembra. The pollen tube
length averaged between 57.11 μm in P. bungeana and 139.2 μm in P. mugo. Both these
pollen viability parameters were compared by Duncan test and variation analysis ( anova ).
Our results indicate that pollen quality characteristics are more similar in closely related
species of pines with pollen shedding in the same period than in systematically distant species
with different periods of their pollen shedding. We suppose annual variation in the pollen
quality of systematically related species that are shedding their pollen at the same time and
which show similar behaviour in several aspects of pollen development. Expected impact of
other factors is discussed.