• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.618-624
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• 2010

This study was conducted to establish the in vitro seed germination of Loranthus tanakae. A factorial experiment evaluated the effects of seed storage duration (0, 8, 16 weeks), media (MS, SH, White, WPM), presence of viscin, GA3, gelling agent and concentrations. Seed germinated after one week culture in in vitro condition and produced radicles. In vitro seed germination was optimal when the seeds removed viscin placed on SH medium (69%) and the addition of 0.35% gelrite (75%) in the same medium. As seed storage duration was expanded to 8 or 16 weeks, in vitro seed germination rate was reduced rapidly. Holdfasts were also produced at the side of radicles. The important factors to produce holdfast and haustorium was kind of media as an optimal condition in White medium without any supplements to be shown 98% and 8% respectively. Process of in vitro germination of Loranthus tanakae was followed to radicle elongation, holdfast development and then haustorium formation sequencially.

• Journal of Korean Society of Forest Science
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• v.99 no.5
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• pp.663-672
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• 2010

The pollen morphology of eleven species and three forms of the genus Rhododendron (Ericaceae) in Korea was examined using light, scanning electron and transmission electron microscopy. The pollen grains are grouped in permanent tetrahedral tetrads; viscin threads are present on the tetrads. The hexacolporate tetrads are of tricolporate monads whereby the apertures form in pairs at six points in the tetrad. The exine sculpture pattern is rugulate, scabrate or verrucate on mesocolpium but psilate, rugulate or microscabrate around the aperture on apocolpium. The exine of Korean Rhododendron pollen consists of tectum, columella, foot layer and endexine. The surface of viscin threads is more or less smooth. The threads are sometimes tangled together and occasionally divided into strands. Six types are recognized based on the pollen morphology. The types are: (1) Micranthum-type (rugulate mesocolpium and psilate apcolpium), (2) Tomentosum-type (rugulate mesocolpium and apocolpium), (3) Aureum-type (scabrate mesocolpium and rugulate apocolpium), (4) Brachycarpum-type (scabrate mesocolpium and rod shaped-microscabrate apocolpium), (5) Schlippenbachiitype (scabrate mesocolpium and round-microscabrate apocolpium) and (6) Weyrichii-type (verrucate mesocolpium).