RAPD分析氮离子注入甜菊种子后的幼苗基因组DNA变异

应用ＲＡＰＤ 技术检测经低能氮离子注入甜菊纯系种子引起的幼苗基因组ＤＮＡ 变异。筛选出ＯＰＪ系列中的１５ 种引物对实验及对照基因组ＤＮＡ 进行了ＰＣＲ 扩增,共获扩增片段１０３ 条,分子量在０．３ － ３ｋｂ 之间,其中５ 种引物ＯＰＪ－ １ ,７ ,９,１１ ,１２ 扩增出差异片段１２ 条。结果表明,低能氮离子注入甜菊种子可引起体内基因组ＤＮＡ 发生突变;ＲＡＰＤ 技术是检测基因组ＤＮＡ 发生诱变的一种简便、有效方法。本文同时探讨了离子强度和Ｔａｇ ＤＮＡ 聚合酶用量对甜菊ＲＡＰＤ 分析结果的影响,以及氮离子注入诱变效应的可能机制。     

Enrichment of the rebaudioside A concentration in Stevia rebaudiana extract with cyclodextrin glycosyltransferase from Bacillus licheniformis DSM 13

Stevia rebaudiana is a sweet herbaceous perennial plant, which is frequently used in the preparation of plant-based sweeteners. The demand for such sweeteners continues to increase due to purposeful nutrition and modern-day metabolic syndromes. More than 20 types of steviol glycosides provide a sweet taste, which are more than 300 times sweeter than sucrose. They are formed of two main components, namely stevioside and rebaudioside A. Only a handful of studies have dealt with Stevia rebaudiana leaf extracts, the conversion of pure stevioside into the preferred rebaudioside A is more common. The aim of this study was to enrich the rebaudioside A content of Stevia rebaudiana leaf extract using enzymatic bioconversion by applying fermented cyclodextrin glycosyltransferase from Bacillus licheniformis DSM13. Two differently processed plant materials, namely dried and lyophilized Stevia rebaudiana plants, were extracted and compared. Following the bioconversion, the rebaudioside A content was on average doubled. The maximum increase was fivefold with a 70–80% conversion of the stevioside.