| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1990: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1989: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1988: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Research Abstract |
Mature pollen of Angiosperms germinate on the stegma of the same species and elongates pollen tubes, in which the generative nucleus divides into two sperm nuclei capable of fertilization. When protoplasts were isolated from mature pollen which have such two specific functions, after the regeneration of cell wall in culture,how expresses the functions in such regenerated pollen protoplasts was the project of this study.
1. The isolation of protoplasts from mature pollen were examined in various species of Angiosperms, and only 4 species within 43 species of dicotyledons, but 27 species within 31 species of monocotyledons were successful. The success depends on the size of the germination pole.
2. In Lilium longiflorum, protoplasts from mature pollen were isolated at high frequencies (70-90%). After the regeneration of cell wall in culture, more than 80% of them were able to elongate pollen tube on solid germination medium. The regenerated pollen did also germinate on lily stigmata and the pollen tubes elongated into style through the ovule, but the fertilization and the seed formation were not ascertained.
3. When the pollen protoplasts of the lily were electrically induced to fuse, the fused protoplasts elongated essentially one pollen tube, regardless of the cell number of fusion. Fusion of pollen protoplasts between the lily and the other species also resulted in the elongation of one pollen tube. In the pollen tubes, the generative nuclei of both species divided into two sperm nuclei. On stigma of each species, the fused pollen of heterokaryon germinated and elongated pollen tube into style.
4. The function of the pollen tube elongation expressed in fused protoplats between lily pollen and tulip mesophyl cells. In the tubes, the dividing figures of the generative nucleus of the lily and the removal of chloroplasts of the somatic cells were observed one day after germination on solid medium.
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