Expression Degree of Self-Compatibility in Korean Sweetpotato Varieties

Sweetpotato is known as a self-incompatibility crop, but some varieties are self-compatible. Expression degree of selfcompatibility was investigated with thirty three Korean sweetpotato varieties based on the ratio of seed capsule sets, pollen germination and number of pollen tubes in style from intra- or inter-flower pollination. Most of the investigated varieties were selfincompatible. Five varieties such as ‘Hongmi’, ‘Hwangmi’, ‘Sinjami’, ‘Mokpo 34’ and ‘Shinmi’ expressed high degree of selfcompatibility with 6.6~30.3% of pollen germination and the number of pollen tubes per style ranging 1.8~4.3. Some varieties including Wonmi, Seonmi, Borami and Mokpo 32 were also self-compatible, even though the degree of self-compatibility were very low in pollen germinations and pollen tubes. Expression degree of self-compatibility can be effectively investigated by the observation of pollen germination and pollen tubes from intra-flower self pollination.