Studies on the Dynamics of Endogenous GAs, ABA and IAA in the Shoot Apex of Chinese Pine in Relation to Male Cone Bud Initiation

The endogenous GAs, ABA and IAA in the shoot apices of 8-year-old Chinese pines, flowered, non-flowered and non-flowered but treated with GA4/7 were analyzed by GC-MS-SIM.The results demonstrated that GA3 and GA9 levels were obviously higher in flowered plants than in non-flowered. A peak value of GA3 in flowered plants occurred after appearance of the earliest auxiliary bud primorda which had the possibility of transforming into male cone bud primordia and before the morphological initiation of male cone bud primordia. Exogenously applied GA4/7 could enhance the endogenous GA3 and GA9, this may benefit the promotion of male cone buds in Chinese pine. The relations among ex-ogenously applied GA4/7 endogenous GAs, ABA and IAA in the shoot apices, and the initiation of male cone bud are discussed.

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。

樟子松球花芽形态分化研究

[目的]观察研究樟子松大小孢子叶球分化的过程及形态学特征。[方法]采用石蜡切片法对内蒙古樟子松雌雄花芽分化过程进行形态学观察。[结果]小孢子叶原基于7月20日左右形成,8月中旬形成小孢子囊,经过冬季休眠,于第2年4月中下旬开始减数分裂,5月7日左右花粉粒成熟;大孢子叶球原基于8月5日左右形成,随后加速分裂,在8月中旬形成芽鳞原基及中轴,第2年5月上旬,苞鳞原基分化,5月20日左右大孢子叶球原基趋于完善,胚珠形成。[结论]确定了各个分化时期的时间,为樟子松花期调控提供帮助。