濒危植物合柱金莲木种子萌发特性

研究了合柱金莲木种子萌发的生物学特性,以了解该物种种群自然更新困难的原因和机制。结果表明:合柱金莲木种子萌发的适宜温度为25℃,萌发率为56.67%,在20℃和30℃条件下,萌发速度和萌发率均较低,且在30℃条件下,幼苗不能正常生长,萌发在15℃受到抑制。土壤含水量在20%～30%,种子正常萌发,随着土壤含水量的升高,萌发开始时间缩短,萌发速度加快。种子萌发需要光照,为需光种子。种子在河沙、粘质壤土、沙土3种不同的基质中萌发率并无显著差异,但在粘质壤土和沙土中生长的幼苗长势较好。不同地理种源的种子,其种子质量存在差异,融水种群种子萌发率高,幼苗长势好。合柱金莲木种子萌发速度慢,萌发不整齐,幼苗生长缓慢,使得其在种间竞争中处于不利地位,且种子萌发对温度的适应范围狭窄,再加上林下光照不足限制种子萌发,这些因素是导致该物种自然更新困难的重要原因。

Seed germination characteristics of endangered plant Sinia rhodoleuca

In this paper,the biological characteristics of Sinia rhodoleuca seed germination were studied,aimed to understand the underlying mechanisms relevant to the impediment in the regeneration of S.rhodoleuca population.The optimal temperature for the seed germination of S.rhodoleuca was 25℃,with a germination rate being 56.67%.At 20℃and 30℃,both the germination velocity and the germination rate were low;at 30℃,the seedlings grew abnormally;at 15℃,the germination was inhibited.When the soil moisture content was in the range of 20%-30%,the seed could germinate normally;with the increase of the moisture content from 20%to 30%,the germination started earlier,and the germination velocity was higher.The seed germination was light-needed,and no seeds could be germinated in the dark.There was no significant difference in the germination rate in sand,loamy soil,and sandy soil,but the seedlings grew better in loamy and sandy soils.The seeds from different geographical provenances differed significantly in their quality,with those of Rongshui population having the highest germination rate and better seedlings growth.The narrow suitable range of temperature and the lack of light in understory limited the seed germination of S.rhodoleuca,and the low germination velocity,uneven germination,and slow growth made S.rhodoleuca be at a disadvantage in interspecific competition.which could be the main causes leading to the poor regeneration of S.rhodoleuca population.