| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 1999: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1998: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1997: ¥2,700,000 (Direct Cost: ¥2,700,000)
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| Research Abstract |
Factors affecting pollen tube growth in the pistils were investigated for grapes, peaches, pears, and apples. In tetraploid grape pistils, where the most of pollen tubes usually stop at the upper part of the ovary, it was found that the pollen tube transmitting tissue (PTT) develops only poorly at the upper and middle parts of the locule at anthesis. Anatomical investigations of the PTT from bud burst until anthesis reveled that in diploid cultivars four to five layers of PTT cells were established at the septum surface 1 week before anthesis and wide intercellular spaces were formed. In tetraploi grapes, however, PTT development were retarded during the period of 3 to 1 week before anthesis, and only one or two layers of PTT cells were formed at anthesis. It was concluded that such poor development of PTT may cause the stop of pollen tube extending into the lower part of the pistils of tetraploid grapes. PTT development in the pistils of peaches, apples, and pears seemed to be sufficient at the upper and middle parts of their pistils but insufficient at the basal part. Most of the pollen tubes stopped at the pistil base, which suggests that the PTT development might be potentially affecting the pollen tube growth in those pistils.
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