EVALUATION OF GROWTH, ACTIVE INGREDIENTS AND GENETIC DISTANCES OF SOME ECOTYPES OF STEVIA (Stevia rebaudiana Bert.) PLANT

Abstract

In order to evaluate growth, active ingredients and genetic distances of some ecotypes of stevia (Stevia rebaudiana Bert.) plant, the samples were collected from Sharkia, Cairo, Damietta and Kafrelshakh Governorates during the two consecutive summer seasons of 2022 and 2023. The collected samples of stevia plants from different regions under study pointed out that the highest values of plant height, leaf number per plant, as well as fresh and dry herb weights per plantwere obtained from Damietta Governorate compared to the other ecotypes. Whereas, the highest values of root length were noticed under Sharkia Governorate region with significant difference with the other regions under study.Also, Sharkia and Cairo Governorate regions recorded the highest values of total carbohydrates percentage and total chlorophyll content, respectively. Two compounds of glycosides of Stevia rebaudiana plant were identified by HPLC. The main componentswere the stevioside which followed by rebaudioside. More increases in stevioside and rebaudioside contents were resulted under Sharkia and Kafrelshakh regions. The dendrogram shows that two groups of the populations separated very early from each other in past to form discrete populations. The ecotypes of Sharkia and Cairo regions were observed in a unique cluster, providing some common phylogenetic relationship among them. Conclusively, through this study, it is preferable to conduct several studies on environmentally different medicinal and aromatic plants depending on the growth and production areas to determine the best agricultural regions for them in terms of growth, yield, and active substances. Keywords:Stevia rebaudiana, Ecotypes, growth, genetic distances, stevioside, rebaudioside. In order to evaluate growth, active ingredients and genetic distances of some ecotypes of stevia (Stevia rebaudiana Bert.) plant, the samples were collected from Sharkia, Cairo, Damietta and Kafrelshakh Governorates during the two consecutive summer seasons of 2022 and 2023. The collected samples of stevia plants from different regions under study pointed out that the highest values of plant height, leaf number per plant, as well as fresh and dry herb weights per plantwere obtained from Damietta Governorate compared to the other ecotypes. Whereas, the highest values of root length were noticed under Sharkia Governorate region with significant difference with the other regions under study.Also, Sharkia and Cairo Governorate regions recorded the highest values of total carbohydrates percentage and total chlorophyll content, respectively. Two compounds of glycosides of Stevia rebaudiana plant were identified by HPLC. The main componentswere the stevioside which followed by rebaudioside. More increases in stevioside and rebaudioside contents were resulted under Sharkia and Kafrelshakh regions. The dendrogram shows that two groups of the populations separated very early from each other in past to form discrete populations. The ecotypes of Sharkia and Cairo regions were observed in a unique cluster, providing some common phylogenetic relationship among them. Conclusively, through this study, it is preferable to conduct several studies on environmentally different medicinal and aromatic plants depending on the growth and production areas to determine the best agricultural regions for them in terms of growth, yield, and active substances.