Study on Stem Cutting Propagation of Gynostemma Pentaphyllum (Thunb.) Makino in Hoa Binh Province

Abstract

Gynostemma pentaphyllum (Thunb.) Makino is a medicinal plant distributed mostly in the mountainous areas of Vietnam. G. pentaphyllum contains more than 189 types of saponin which can be used for the treatment of various diseases. Currently, due to over-exploitation, this plant species is under threaten. Our research aimed to study a suitable method for plant propagation by stem cutting techniques to promote the growth and development of G. pentaphyllum. Six experiments were conducted to (i) evaluate the established seedling rates of different G. pentaphyllum varieties, and choose the best variety to (ii) evaluate the established seedling rate influenced by different factors, viz. stem cutting position, cutting season, growing in the selected substrates, stem cutting length, number of buds per stem, and application of α-NAA. The results showed that among five varieties, G2 which was collected in Mai Chau district disclosed the highest ability to shooting, the highest number of roots per stem cutting, the shortest nursery days, the highest shooting rate, and the highestestablished seedling rate. We also determined that using middle-aged plants for stem cuttings, at 15-20cm in length, with 2 nodes and grown in Spring and Winter cropping seasons, using growing substrates with a mixture of 50% of black sand and 50% of soil, and plus α-NAA 50ppm in 3-5min produced the highest explant rate. The established seedlingsat the time of explant were 15-20cm in height, containing 4-5 leaves and at least 9-10 roots per cutting, and were 30-32 days.