In-vitro regeneration of Populus langfangensis 3 for transformation and micropropagation

Abstract

The direct and indirect induction of organ differentiation,callus formation and plantlet regeneration from the leaf and stem explants of the hybrid Populus langfangensis 3(P.deltoides("Shan Hai Guan")×((P.simonii × pyramidalys)_(12) × Ulmus pumila) were investigated in-vitro on Murashige and Skoog(MS) medium supplemented with various concentrations of benzylaminopurine(BA),indole-3-butyric acid(IBA),1-naphthaleneacetic acid(NAA) and 2,4-dichlorophenoxyacetic acid((2,4-D)).The petiole and leaf explant was easier for direct shoot regeneration along the veins at cutting sites.Direct shooting efficiency was related to both BA concentration and BA/IBA ratio.Efficient and rapid shooting from the leaf and stem explants was achieved on MS medium containing 1~2 mg·L~(-1) BA and 0.5 mg·L~(-1) IBA. Maximum shooting frequency reached 90%.2,4-D promoted the callus induction of P.langfangensis 3.The shooting based on callus was obtained on MS medium supplemented with(0.3~0.5 mg·L~(-1)) BA and 0.02 mg·L~(-1) IBA or NAA and the corresponding shooting frequency was 76%.Rooting based on callus succeeded on 0.1 mg·L~(-1) BA and 0.2~0.5 mg·L~(-1) IBA,yielding rooting frequency 67%.These regeneration conditions could further be used for micropropagation and transformation of P.langfangensis 3.