A STUDY ON VA MYCORRHIZAE FORMED ON THE TISSUE-CULTURED PLANTLETS OF PAULOWNIA

Tissue-cultured plantlets of 2 Paulownia species (Paulownia fortunei (Seem.) Hemsl. and P. albiphloea Z. H. Zhu. sp. nov.) were inoculated with Glomus epigaeum Daniels & Trappe in containers containing mixed substrate of peat-vermiculite-sand-soil (2:1:1:1 v/v). After 30 days of inoculation, growth of plantlets between the inoculated and uninoculated treatments showed a significant difference in shoot height, collar diameter and foliage area, but there was no difference between the species. The observation of vertical distribution of VA mycorrhizae on the root system of Paulownia seedlings showed that most of VA mycorrhizae were concentrated in the top 10 cm soil layer. The morphology and fine structures of these mycorrhizae were also studied by light and scanning electron microscopes. The distribution of several nutrient elements in these mycorrhizae was detected with X-ray microanalysis, spectra of which showed that arbuscules, vesicles and hyphae contained more P, S, Mg and Ca than the uninoculated plantlets did.