马尾松雌球果的发生和早期发育研究

采用常规石蜡制片技术对马尾松雌球果的发生和早期发育进行了研究。结果表明：雌球果原基发生时间为10月中旬，不同的树龄和着生部位，其发生时间不同。雌球果原基与营养茎端在外部形态及内部细胞组织学分区结构有明显差异。营养茎端外形扁平，内部顶端分生组织结构有顶端原始细胞区、中央母细胞区、形成层状过渡区、周围分生组织区及肋状分生组织区5个明显的分区；而雌球果原基外形呈圆锥状，内部结构只有套层和髓区。12月初，最初的苞片原基在雌球果原基的鳞片的叶腋处产生，之后其由基部向顶部连续发生。翌年1月初，在苞片原基的叶腋处，珠鳞原基发生，发生方向亦为向顶发育。2月底，苞片体积不再发生变化，珠鳞膨大端的基部的近轴面分化出2个倒生胚珠。从雌球果原基发生到胚珠分化历时4个多月。亚热带的冬季气候对马尾松雌球果的生长发育没有明显的抑制作用。

Initiation and early development of the ovulate strobilus in Pinus massoniana

The paraffin section technique was applied in the study of the initiation and early development of the ovulate strobilus in Pinus massoniana Lamb. from September to April cultivated at the campus of South China Agricultural University.Result is as follows: In the middle of October, the primordium of ovulate strobilus occurred, its occurrence time varied between different aged ramets and different occurrence part. Morphology and cytohistological zonation appeared different between cone apex and the vegetative shoot apex. The vegetative shoot apex is thin and flat morphologically, and its cytohistological zonation pattern is an apical initial zone, a central mother cell zone, a cambium like transitional zone, a peripheral zone, and a rib meristem, while cone apex is coniform, and its apex structure consist of outer mantle and inner pith. In the early December, the first bract primordium was formed in the axil scale at the cone base, then bract initiation had occurred in acropetal direction. In the early January, ovuliferous scale primordial were acropetally formed in the axils of the developing bracts. At the end of February, the bract attained approximately their full size, and a pair of anatropous ovules were initiated on the adaxial surface at the base of the fertile ovuliferous scale. It lasted for more than four months from initiation of the ovulate strobilus to formation of anatropous ovules. The sub tropical winter weather has no apparent inhibition for the growth and development of the ovulate strobilus in Pinus massoniana .