闽楠微扦插繁育体系的建立

  目的   以闽楠Phoebe bournei近成熟胚为外植体，采用多种方法建立闽楠微扦插繁殖体系。  方法   探究不同子叶切除强度对胚褐化的影响，以及抗褐化剂和吲哚丁酸（IBA）对近成熟胚萌发和无菌苗微扦插生根的影响。  结果   闽楠近成熟胚褐化的主要部位为子叶，子叶切除后胚可以萌发但不能正常生长，添加聚乙烯基吡咯烷酮（PVP）对抑制子叶褐化有明显效果且不影响胚的萌发。近成熟胚萌发最佳培养基为1/2MS+0.2 mg·L-1 IBA+2 g·L-1 PVP，萌发率最高可达89.71%。无菌苗微扦插最佳生根培养基为1/2MS+1.5 mg·L-1 IBA+2 g·L-1PVP，顶芽生根率为100%，平均生根数为3.86条，平均根长1.56 cm；侧芽生根率为60.27%，平均生根数为1.55条，平均根长0.85 cm。筛选出的3号株系的繁殖系数达24.40。  结论   研究结果可为闽楠良种繁育提供参考。

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.