细枝木麻黄离体培养过程中愈伤组织和再生芽的细胞组织学观察

为探讨细枝木麻黄(Casuarina cunninghamianaMiq.)愈伤组织分化过程的细胞组织学，对离体培养条件下的愈伤组织进行扫描电子显微镜和石蜡切片观察，分析愈伤组织的细胞分裂、分化以及芽再生的发生过程。结果表明，新鲜外植体培养于愈伤组织诱导培养基上，伤口处的薄壁细胞开始脱分化，培养1周后形成明显的愈伤组织；继续培养2周后，胚性愈伤组织形成，且表层细胞启动分化形成芽原基；培养4周，可肉眼观察到胚性芽原基，数量增多并逐渐分化形成不定芽；培养至第6周，生成不定芽，并大量增殖和分化。因此，细枝木麻黄是通过愈伤组织分化形成胚状体的途径进行植株再生的，为建立细枝木麻黄组织培养高效再生体系提供了理论依据。

Cytohistological Observation of Callus and Adventitious Buds of Casuarina cunninghamiana Miq. in vitro

In order to understand the cytohistology of Casuarina cunninghamiana callus, cell division, callus differentiation and adventitious bud regeneration were studied under scanning electron microscope and paraffin sections. The results showed that parenchyma cells in the wound started dedifferentiation in the callus induction medium. After cultured for one week, callus were induced at the explant wound, and embryonic callus was formed. Bud primordium was induced from surface cells after two weeks. After culturing for a further four weeks, embryonic bud primordium became more increasely visible, and gradually differentiated to become adventitious bud. After another six weeks, most of the adventitious buds have proliferated and differentiated, and some developed to shoots. It was confirmed that the regeneration of C. cunninghamiana could be achieved through embryoid callus differentiation, it would provide basis for establishment of efficient regeneration system in C. cunninghamina.