Factors Affecting the Growth and Survival of in vitro Grafted Apple
Wang Qiaochun(Research Centre for Horticultural Plants,Sichuan Acaderey of Agricultural Sciences,Chengdu,Sichuan, 610066)
In vitro grafted apple was successfully achieved by using M26 and ‘Gala’ as rootstock and scion. Resultsshowed that growth and survival of in vitro grafts when cultured on MS liquid paper bridge were superior toon MS solid medium. Liquid medium, however,caused rootstock to become swelling and vitrification. An earli-er callus formation in graft union ,higher survival and greater growth of in vitro grafts were obtained as BAPconcentration increased. High BAP concentration(≥0.8mg ·1￣(-1)) ,however,induced production of side shooton rootstock,swelling and vitrification of rootstock. A significant lower rooting was also found at ≥0.8mg·1￣(-1) BAP. The optimum BAP concentration for establishment of in vitro grafts was 0. 4mg ·1￣(-1). Rooting of invitro grafts increased markedly as an increase in IBA concentration with 1. 0mg· 1￣(-1)IBA being the optimum.Effect of IBA on growth of in vitro grafts showed was the same pattern as on rooting.