齿瓣石斛的原生境播种及其株丛生长特性研究

摘要

Seed germination and growth are critical for orchid conservation and sustainable utilization,yet most orchid seeds are tiny and lack an endosperm and suitable nutrition.Based on previous experience,two experimental sowing methods (sowing with diluted cow-dung + seed and rice-water + seed) for Dendrobium devonianum Paxt.were applied successively to sow on the trunks of different tree species in the field.The seedlings were monitored and recorded for four years.Results showed that many seeds germinated and developed into seedlings.The seedlings grew slowly in the first year and had short stems,with three to five years required to reach the flowering stage.Growth and fruiting varied greatly on the different tree trunks,with the highest fruiting set rate of 24.86％ recorded from plants on the trunks of Pyrus × michauxii.Our study suggested that D.devonianum could be sown directly on trunks in native habitats.Based on our results and the large number of seeds per fruit,this method could be applied as a potential new strategy for commercial cultivation and for conservation in the field.%兰科(Orchidaceae)植物是植物保护中的“旗舰”类群,其种子细小粉末状,缺乏萌发所需的营养物质,研究种子萌发和幼苗生长特性对于兰科植物保育、资源可持续利用和产业化等具有重要意义.本研究以附生齿瓣石斛(Dendrobium devonianum Paxt)为对象,建立原生境播种方法,研究其生活史周期和不同附主树种齿瓣石斛株丛生长特性.结果显示,采取稀牛粪+种子(或米汤+种子)的原生境播种方法,齿瓣石斛种子可大量萌发生长形成幼苗;种子萌发当年生长缓慢,完成由种子到种子的生活史周期需3～5年或更长;不同附主树种的齿瓣石斛株丛生长及结果情况存在差异,4年生假鳞茎在不同附主树种上的茎节数指标为:李树＞梨树＞桃树＞披针叶楠;茎粗指标为:披针叶楠＞梨树＞桃树＞李树;茎长指标为:梨树＞披针叶楠＞李树＞桃树;结实率指标为:梨树＞桃树＞李树＞披针叶楠,其中,梨树上的齿瓣石斛株丛自然结果率达24.86％.该研究为附生石斛的原生态栽培和回归保育提供了一条新途径.