To find out the effect of the pollen cultivars on the fruit sets and fruit characteristics in the `Niitaka´ pear cultivar and to select the suitable pollinizers for `Niitaka´ pear, this experiment has been conducted using 8 pollen cultivars.
The results obtainted were as follows:
1. Five-year records indicated that all the cultivars observed except `Okusankichi´ bloomed almost simultaneously with `Niitaka´ cultivar.
2. Pollen viability and germination ability were good with no differences among the cultivars observed. The anther of `Kosui´, `Shinsui´ and `Chojuro´ pear contained more pollen grains than that of other cultivars.
3. Counting the number of pollen grains in one anther after relative humidity treatment with saturated solutions revealed that pollen dehiscence was well-done under 80% RH condition than 98% RH or 53% RH condition.
4. There were no differences in fruit set, soluble solids, flesh firmness and fruit stem length when `Niitaka´ crossed with 8 pollinizers.
5. Fruit weight and number of seeds in the fruits crossed with `Imamuraaki and `Okusankichi´ were smaller than that of other pollen sources. Fruits crossed with the above 2 cultivars tend to have oblong shape.
6. On the bases of bloom date, pollen amount and effect on the fruit sets and characteristics, `Chojuro´, `Waseaka´, `Hosui´, `Kosui´ and `Shinsui´ were selected as suitable pollinizers for `Niitaka´ pear.
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