Organogenesis and plantlet regeneration following in vitro cold storage of kiwifruit shoot tip cultures

Abstract

Shoots were cut from kiwifruit ( Actinidia deliciosa (A. chev.) C.F. Liang et A.R. Ferguson var. deliciosa) shoot tip cultures which had been stored at 8°C for 52 weeks, from 52-week-old cultures continuously maintained at the shoot proliferation stage at 23°C, and from 8-week-old proliferating cultures. The excised shoots were re-cultured in proliferation medium for 1 month and in vitro organogenesis was examined. There was no difference between the three types of shoot cultures in fresh weight gain or in shoot production, but the number of roots produced was greater in the shoot cultures derived from the cold-stored cultures than in those derived from the cultures maintained at the proliferation stage. All plantlets regenerated from all three treatments survived. Therefore, storage of kiwifruit shoot tip cultures in vitro for 52 weeks at 8°C did not impair subsequent in vitro organogenesis of sub-cultured shoots or plantlet regeneration.