Low-chill trait for endodormancy completion in Actinidia arguta Planch. (Sarunashi) and A-rufa Planch. (Shima-sarunashi), indigenous Actinidia species in Japan and their interspecific hybrids

摘要

Budbreak on 2-bud cuttings of Actinidia arguta and A. rufa, exposed to 200 hr of natural chilling below 7degreesC and additional chilling at 4degreesC was compared with that of kiwifruit, A. deliciosa and A. chinensis. A high percentage of budbreak occurred in A. arguta and A. rufa indicating that they have a very low chilling requirement, namely 200 hr, under natural conditions, whereas A. deliciosa cultivars required 600-800 hr or more of chilling; chilling requirement of A. chinensis was intermediate. Some interspecific hybrids also exhibited a low chilling requirement.