遗传质量对水青树(Tetracentron sinense Oliv.)种子特征及幼苗初期生长的影响

The Effect of Different Pollination Treatments on the Seed Character and Seedling Initial Growth of Tetracentron sinense Oliv.

通过对不同授粉处理后的水青树种子特征及幼苗生长等指标进行比较分析,探讨遗传质量对水青树种子和幼苗适合度的影响。研究发现,不同授粉处理后的水青树种子的宽和厚、千粒重、饱满度,以及萌发率和发芽势均存在显著差异:来自异株异花授粉处理的种子的厚度、千粒重、萌发率和发芽势均明显高于自花和同株异花授粉处理,其幼苗茎的生长优于自花授粉及自然授粉的幼苗,根的生长在后期也超过了这2种处理;来自自然授粉的水青树种子的宽度、厚度和萌发率均明显低于自花授粉和同株异花授粉处理,而其长度、千粒重、发芽势等指标均与自花授粉处理的种子没有明显区别。结果表明:种子遗传质量显著影响水青树种子和幼苗的适合度,异株异花授粉后的种子和幼苗的适合度最高。自然生境中水青树的自交生殖策略可能与其恶劣的环境条件(其花期与雨季重合)和种群密度过小有关。

By comparative study of the seed character and seedling growth of Tetracentron sinense Oliv.after different pollination treatments,the effect of seed genetic quality on the fitness of seed and seedling is explored.It is found that there are significant differences in the width,thickness,thousand grain weight,plumpness,germination rate and germinative force of T.sinense seeds after different pollination treatments.The thickness,thousand grain weight,germination rate and germination force of seeds from xenogamy are significantly higher than those from self pollination and geitonogamy;the growth of seedling stem is better than that from self and natural pollination;the growth of seedling root in the later period also exceeds these from other treatments.The width,thickness and germination rate of seeds from natural pollination are significantly less than those from the self pollination and geitonogamous,but there is no significant difference in the length,thousand grain weight,and germination force of seeds between natural and self pollination.The results indicate that:(1)seed genetic quality of Tetracentron sinense has a significant effect on the fitness of seeds and seedlings;(2)The fitness of seeds and seedlings from xenogamy is the highest;(3)In the natural habitat,T.sinense applies a reproductive strategy of inbred,which may be attributed to the harsh environmental conditions(its flowering period coincided with the rainy season)and the lower population density.