Screening Of Fine Germ Plasm In Dioscorea Zingiberensis Wright.and Researches On Its Tetraploid Rapid Propagation And Integral Economic Traits

Dioscorea zingiberensis Wright is an important kind of medicinal plant, whose main secondary metabolite , dioscorea , is the beginning material for homne medicines synthesis such as condom which is widely used in medicine production. D. zingiberensis Wright is now most widely used in the industry for its highest content of of dioscorea on the average of 2.5%. So it has become the first choice of raw material for homne medicines synthesis. But, because of excessive exploitation of the wild resources , natural Dioscorea zingiberensis Wright is on the edge of extinction; So cultivated Dioscorea zingiberensis Wright has been in large scales taken the only raw material for Dioscorea zingiberensis Wright industry. However, there still remains many troubling problems such as blindly mixed cultivation of geographically widely distributed Dioscorea zingiberensis Wright plants which have different subspeices or forms and vary distinctly in dioscorea contents and other traits and the many-years-growth-produced germ plasm involution which leads consequent problems as low dioscorea contents , poor total production and accordingly low prices for farmers.In order to find ways to solve these existing problems , this thesis made researches on screening of fine quality subspieces or forms, relationship between eyeable characters and high dioscorea content or integral economic indexes ,rapid propagation of tetraploid Dioscorea zingiberensis Wright and its germplasm as follows :(1) In related researches , production and purchasing , the traditional ways of determination of dioscorea content are the main block which is of low efficiency and of high cost and puts too many trubles such as being unable to make determination of dioscorea content in large scales of Dioscorea zingiberensis Wright smaples and make it impossible to obtain objective scientific results in the industry of Dioscorea zingiberensis Wright. This thesis made improvement on the traditional determination methods and set up a new method of determination in which diosgenin is separated through micro-extraction with chloroform assisted with ultrasonic treatment instead of through circumfluence and then oxidized by Liebemann-Barcharad reagent and finally determined with a spectrometer. This method was proved to be simple , accurate, low-cost and highly efficient.