Abstract
Intergeneric crosses between Japanese pear (Pyrus serotina Rehd. var. culta Rehd.) and apple (Malus pumila Mill. var. domestica Schneid.) were carried out in 1974, 1976 and 1977 in order to obtain the basic information for intergeneric hybridization. In 1974, Five pears and three apple cultivars were crossed reciprocally. Out of 1306 pear flowers crossed with apple pollen, 221 fruits were obtained, and 4 fruits in them were seedless. The fruits with seeds gave 1172 fertile seeds. The rate of the fruit set was 16. 9 percent .and the average seed number per fruit with seeds was 5. 4. The fruit set and the seed fertility in the intergeneric hybridization were remarkably lower than those in intervarietal crosses between pear cultivars. From 1152 apple flowers pollinated with pear pollen, 118 mature-fruits were obtained and 4 fruits in them were seedless. The rate of fruit set was 10. 2 percent. From the fruits with seeds, 362 seeds were obtained and the average seed number being 3. 2.
