长白落叶松生殖生物学特性研究──Ⅰ．球花芽分化与早期发育

本文研究了长白落叶松（ＬａｒｉｘｏｌｇｅｎｓｉｓＨｅｎｒｙ）大小孢子叶球的分化及其分布规律．获得如下结果：（１）６月下旬芽鳞形成期终止，７月初进入小孢子叶分化期，７月未至８月上旬小孢子叶分化期结束．８月上旬进入小孢子囊分化期，８月下旬出现造孢细胞，９月中旬形成小孢子母细胞．１０月底小孢子母细胞保持在细线期阶段，小孢子叶球进入冬季休眠期．（２）９月初苞片原基开始形成，９月中旬珠鳞原基形成；１０月上旬出现胚珠原始体，１０月下旬大孢子母细胞形成，１０月底大孢子叶球芽进入冬季休眠．（３）小孢子叶球芽主要分布在树冠的中、下部．数量上远远大于大孢子叶球芽的数量，约为大孢子叶球芽的１９倍。大孢子叶球芽主要集中分布在树冠中部，而且树冠下部多于树冠上部。

A STUDY ON BIOLOGICAL CHARACTERS OF REPRODUCTION OF LARIC OLGENSIS HENRY I. DIFFERENTIATION AND EARLY DEVELOPMENT OF CONE FLOWER BUDS

This paper studied the differentiation and the regularitics of distribution of megasporophyll and microsporophyll cones of Zhangbai larix (Larix olgensis Henry). Results were: (1) in the last ten days of June, the period of bud scale formation ended, the period of differentiation or microsporophyll began at the beginning of July and ended between the end of July and the early of August. In the first ten days of August, the ment entered into the period of microsporagia formation, sporogenous cells appeared in the last ten days of August and microsporocytes were formed in the middle ten days of September. At the end of October, microsporocytes remained in the stage of Leptotene and then went into winter dormancy. (2) At the beginning of September, bract primordia initiated to form, In the middle ten days of September, primordia of ovule scales formed, in the first ten days of October primary ovules appeared, in the last ten days of October,megasporocytcs were formed, and at the end of October megasporophyll cone buds went into winter dormancy. (3) Microsporophyll cone buds mainly distributed in the middle and lower regions of the crown and greatly exceed megesporophyll cone buds in number, at about 19 folds. Megasporophyll cone buds mainly concentrated in the middle region of the crown, while number of budsin the lower region were greater than that in the upper.