3种四照花一年生播种苗生长规律初探

Annual Growth Rhythm of 1-year-old Seedlings of Three Cornus Species

摘要:

为揭示3种四照花的苗期生长规律，对1 a生大花四照花（Cornus florida）、香港四照花（C.hongkongensis）和东京四照花（C.hongkongensis subsp.tonkinensis）幼苗的年生长节律进行了观测分析。结果表明，根据拟合的Logistic方程生长模型（R²> 0.98，P<0.01），可将3种四照花苗期的苗高和地径年生长进程划分为生长初期、生长盛期、生长后期3个时期。其中，生长盛期的苗高和地径的生长量分别占全年的55.23%~59.06%和59.46%~60.71%。大花四照花的年生长积累均大于2种东亚类常绿四照花，而香港四照花和东京四照花的苗高和地径生长相似；大花四照花的生长初期和生长盛期的启动时间早于2种东亚类四照花，但持续时间最短。3种1 a生四照花的苗高和地径生长呈现出"慢-快-慢"的生长节律，符合"S"型生长曲线；且地径和苗高呈现出异速生长现象。这为四照花栽培推广、引种驯化提供了理论依据。

Abstract:

In order to reveal the growth rhythm of Cornus, the height and ground diameter of one-year-old seedlings for C. florida, C. hongkongensis and C. hongkongensis subsp. tonkinensis were observed. According to the fitting analysis using Logistic equation for three Cornus seedlings (R²>0.98, P<0.01), the seedling growing process of both height and ground diameter could be divided into 3 stages, including initial stage, fast stage and later stage. Among three stages, the seedling growth of height and ground diameter at fast stage accounted for 55.23%-59.06% and 59.46%-60.71%, respectively. The annual growth accumulation of C. florida were larger than the other two evergreen Cornus species, while the seedling growth patterns of height and ground diameter for C. hongkongensis and C. hongkongensis subsp. tonkinensis were similar. The starting time of initial and grow fasting stages of C. florida were earlier than that of two evergreen others, but the duration of two stages of C. florida were also shorter than that of evergreen ones. In conclusion, the growth rhythms of height and ground diameter of one-year-old seedlings of three Cornus showed the similar pattern of "slow-fast-slow", according with "S" shape. Moreover, the growth of height and ground diameter of Cornus seedlings was allometric. So, these would provide the theoretical foundation for cultivation promotion, introduction and domestication of Cornus.