白桦雌花发育的形态相关

以20年生白桦的雌花序为材料,研究了白桦雌花发育时序特征和形态相关性,测量了不同发育时期种子的纵径、横径、横径(含种翅)及花柱长。纵径、横径和横径(含种翅)随着发育进程呈现逐渐增长趋势。减数分裂之前的4月底至5月中旬期间,纵径与横径处于缓慢增长状态,5月15日到5月28日,减数分裂和配子体形成期间二者增长幅度较大,5月29日以后又趋于平稳。花柱的长度变化不大,纵横径比值呈缓慢平稳增长趋势,而花柱长与纵径的比值变化则较大,呈迅速下降趋势。横径(含翅)与横径相比,其增长幅度在5月21日之后更大,说明种翅在此期间增长较快。白桦花发育各时期的形态特征较明显,因此,根据花外部形态变化大致判断其生殖发育状态是可行的,能在一定程度上利于相关研究的适时取材问题。

Morphological Correlation of Female Flower Development in Birch

An experiment was conducted to study temporal characteristics and morphological correlations of female flower development for female inflorescence of 20-year-old Betula platyphylla on the campus of Northeast Forestry University. The length and width of seeds, width of seed with seed wing as well as the length of style at different developmental periods were measured. Results showed that the width of seed with seed wing and the length and width of seed in female inflorescence of B. platyphylla gradually increased with the developmental process. The length and width of seed grew slowly before meiosis (from late April to mid-May), and grew fast during meiosis and gametocyte formation (15th to 28th May), and then tended to be stable after 29th May. The length of style changed slightly, the ratio of length to width of style increased slowly and stably, and the ratio of style length and seed length decreased rapidly. The width ratio of style to seed with seed wing presented a higher increment after 21st May, indicating that seed wings had a quick growth. Therefore, it is feasible to estimate the development stage of female flower according to its external morphology, which provides some bases for material-collecting at a suitable time.