盾叶薯蓣研究进展

Advances in study of Dioscorea zingiberensis

对国内盾叶薯蓣资源概况、分布范围、生态环境、化学成分、品种选育、组织和细胞培养等研究现状进行评述.盾叶薯蓣是我国特有的甾体激素类药源植物,也是世界上薯蓣皂甙元含量最高的资源植物,广泛分布于北亚热带及中亚热带地区.适宜生长区为陕西南部和湖北武当山区,在海拔400～700m、年平均温度16～18℃、年降水量800～900mm、相对强光913～1004μmol·m-2·s-1之间的山地棕壤和山地黄壤等腐殖质深厚的近酸性土壤中生长较为适宜;由于其长期对环境条件的适应,形成了分化显著的生态型,并且在形态特征与遗传特性等方面表现显著,据此已选育出多个栽培品种;组织培养技术是进行种苗生产、品种培育的有效途径,也是工业化皂甙生产的有效途径;薯蓣皂甙主要分布于根状茎中,根状茎主要由周皮、基本组织和散生在基本组织中的维管束三部分组成,周皮细胞的分裂和体积增大使根状茎迅速生长,薯蓣皂甙主要分布于基本组织薄壁细胞中;影响盾叶薯蓣皂甙含量的因素主要有分布区、海拔、土壤、水分、温度、光照等环境因子,也有株间差异、生长时间、生育期、开花时间、根状茎水分含量及形态等自身因子.

A review of the study on the germplasm resources,natural distribution,adapted cultivating area,ecological environment,chemical constituents,selective breeding,as well as the tissue and cell culture of Dioscorea zingiberensis was given.The species is an endemic Chinese medicinal resource plant,with high content of dioscin quantity in its genus.It is distributed widely in North and Central Subtropical areas,with the most adaptive growth areas in South Shaanxi and Wudang Mountain of Hubei Province.It is more adaptive to mountainous areas with brown and yellow profound humus soils with slight acidity,and because of its long-term adaptive to its different environments,it has formed some remarkably differentiated ecotypes.These ecotypes have obviously morphological and genetic variations,from which a few of cultivated varieties have been selected and bred.The technique of tissue culture is a most effective way to seedling production and variety breeding,and also an effective way to industrial production of diosgenin.The diosgenin is primarily located in rhizome of the yam,and which is composed of periderm,elementary tissue and vascular bundles scattered in the former.The division and increase of periderm cells make the rhizome grow rapidly,and the diosgenin is mainly stored in the parenchymatous cells of the elementary tissue.The factors affecting the content of diosgenin in the yam include mainly the environmental aspects such as distribution area,altitude,soil,moisture,temperature,illumination and the individual aspects of plant such as individual variation,growing time,bearing period,flowering time,water content of rhizome,morphology of rhizome,etc.As a result,some directions to improve adaptive capacity of the yam and increase its content of diosgenin have been put forward in this paper.