濒危植物七子花繁殖器官的形态及其变异

Morphology and variation of apparatus of endangered plant Heptacodium miconioides

对国家 2级保护植物七子花 (Heptacodiummiconioides)的繁殖器官的形态及其变异进行了研究。结果显示 :种群A的生境恶劣 ,花枝的开花数少 ,结实状况不及种群B ,但因仅开基轮花的花序比例低和开三轮花的花序比例高 ,果实和种子的变异较大 ;而种群B的生境条件好 ,开花结实有明显的改善 ,但成熟种子的胚发育也不完全 ,且种子的最大值 (由花序Ⅰ产生 )不及种群A。说明七子花更适合于生境恶劣的条件下生长。另外 ,整枝疏花可以改善其结实状况 ,但效果不显著 ,说明七子花自身的营养调节能力差。因此 ,有性生殖障碍是七子花成为濒危物种的主要原因 。

The morphology and variation of apparatus of Heptacodium miconioides that is a national protected plant species in China were studied. The results showed that the flower and seed number in flower shoot of H. miconioides in population A with diagusting habitat were fewer than in population B with good habitat. The fruit and germ in population A varied richly for the lower percent of panicle only with basal whorls and the more percent of panicle with three whorls. The flowering and seeding improved distinctly in population B, but the embryo of adult germs were underdeveloped. Germs produced in the basal whorl of panicle I in population A was heavier than those in population B. All the results suggested that H. miconioides could grow in diagusting habitat. The sink adjustment could improvement the seed status but the effect was inapparent and it suggested that the H. miconioides had a poor nutrition adjustment by itself. The obstacle in sexual reproduction might be the main reason why H. miconioides is in endangered condition. In order to eliminate this obstacle, the population ecological adapts and renewal of germ plasm could be studied.