A micro-cutting system for breeding of Phoebe bournei

Objective The mature embryos of Phoebo bournei were used as explants, and a variety of methods were used to establish the micro-cutting and breeding system of P. bournei. Method To explore the effects of different cotyledon excision intensities on embryo browning, the type and concentration of anti-browning agent, the effect of indolebutyric acid (IBA) on the germination of near mature embryos, and the rooting of sterile seedlings, nearly-mature cotyledon embryos of P. bournei were used as explants. Result The main browning part of P. bournei nearly-mature cotyledon embryos was the cotyledon. The embryo could germinate but it grew weak after the cotyledon was cut off. The addition of anti-browning agents inhibited the browning. The optimal culture medium for germination of the nearly-mature cotyledon embryo was 1/2 Murashige and Skoog (MS) + 0.2 mg·L-1 IBA + 2 g·L-1 polyvinylpyrrolidone (PVP) with a germination rate of 89.7%. The optimal culture medium for rooting of an aseptic seedling was 1/2 MS + 1.5 mg·L-1 IBA + 2 g·L-1 PVP, and the rooting rate of the apical bud was 100%. The average number of roots was 3.86, and the average root length was 1.56 cm; whereas, the rooting rate of the lateral bud was 60.3%. The average number of roots was 1.55, and the average root length was 0.85 cm. Also, the three selected strains had a reproductive coefficient of 24.40. Conclusion The results could lay a foundation for the breeding of further varieties.