Micropropagation of Two Selected Male Kiwifruit and Analysis of Genetic Variation with AFLP Markers

Abstract

A simple and reliable protocol for micropropagation during 12 subcultures of two field growth male plants of kiwifruit [ Actinidia deliciosa (A.Chev.) Liang and Ferguson] is described. The best results of shoot multiplication and elongation were obtained in Cheng's K(h) medium in the presence of 0.5 μ m NAA, 22 μ m BA and 1.4 μ m GA 3 for `Tomuri' explants, and of 0.1 μ m NAA, 4.4 μ m BA, and 0.3 μ m GA 3 for clone A explants. In addition, the cytokinin compounds TDZ and mT were also tested allowing improving the multiplication rate in `Tomuri' explants. For rooting, `Tomuri' and clone A developed shoots were treated by basal immersion in a 5 m m IBA solution for 15 seconds. Treated shoots were then cultured in half-strength K(h) medium without growth regulators showing 100% rooting after 30 days. Regenerated plantlets were successfully transplanted to soil (90% survival) and they are actively growing in the field. Somaclonal variation analysis by AFLP was carried out using 15 primer combinations, yielding reproducible and well-resolved bands with a 57% of polymorphism. AFLP markers showed to be effective to discriminate genetic variation in this species, being greater in clone A than `Tomuri'. Chemical names used: N 6 -benzyladenine (BA); gibberellic acid (GA 3 ); indole-3-butyric acid (IBA); meta-topolin (mT); naphthaleneacetic acid (NAA); thidiazuron (TDZ).