EVALUATION OF CHARACTERISTICS OF ACTINIDIA INTERSPECIFIC HYBRID ‘KOSUI’

‘Kosui’ is a cultivar recently released from Kagawa Prefectural Agricultural Experiment Station, which is reported to be an interspecific hybrid between A. arguta ‘Issai’ and A. deliciosa ‘Matua’. In this study, several characteristics of ‘Kosui’ were evaluated.
Bud burst occurred in mid-March, as early as A. rufa and 2-3 weeks earlier than A. arguta, A. chinensis and A. deliciosa. The date of full bloom was early May,　almost the same time as A. chinensis, and one-two weeks earlier than other species.
The fruit matured from late October to early November, similar to A. chinensis and A. arguta, and two-three weeks earlier than A. deliciosa and A. rufa. Pollination of ‘Kosui’ with pollen of A. deliciosa ‘Matua’ ‘Tomuri’, A. chinensis ‘FCM1’ ‘FCM2’, A. rufa ‘Kochi’ ‘M2’ or A. arguta ‘Awaji’ gave a rate of fruit set above 70%. Average fruit weight was about 40 g and single fruit contained 350-400 seeds.
However, fruit derived from crossing with A. arguta were relatively small and each contained only about 170 seeds.
TSS of fruit after ripening was 17–18% in all cases.
Fruit of ‘Kosui’ has a greenish-brown skin without hair, and dark green flesh.
Axillary buds of ‘Kosui’ have a chilling requirement much lower than those of A. deliciosa and A. chinensis but similar to those of A. rufa and A. arguta. These results implied that A. rufa and A. chinensis seem to be involved in the origin of ‘Kosui’, rather than A. arguta or A. deliciosa.

V International Symposium on Kiwifruit

I. Kataoka, K. Kokudo, K. Beppu, T. Fukuda, S. Mabuchi, K. Suezawa

Actinidia, chilling requirement, fruit quality, fruit set, interspecific hybrid, kiwifruit, pollination, propagation

https://doi.org/10.17660/ActaHortic.2003.610.11