There are many methods to separate or purify the rebaudioside A compound from Stevia rebaudiana extract. However, the ion-exchange chromatography using macroporous resin is still the most popular among those methods. The separation of rebaudioside A from stevia crude extract by macroporous resin AB-8 was optimised in this adsorption separation study. This approach was applied to evaluate the influence of four factors such as the adsorption temperature, desorption time, elution solution ratio, and adsorption volume on rebaudioside A yield of the purified stevia extract. The results showed that the low polarity resin AB-8 is able to separate rebaudioside A from stevia extract with 0.601 in yield compared to the high polarity resin HPD 600 with 0.204 in yield used in Anvari and Khayati study. The best conditions for rebaudioside A separation by macroporous resin AB-8 were at 35°C of adsorption temperature, 30 min of desorption time, elution solution ratio 2:1, and 50 mL of adsorption volume.
Stevia rebaudiana Bertoni is a perennial herb that belongs to the family of Asteraceae. It is a
natural sweetener plant known as sweet leaf, which is estimated to be 300 times sweeter than cane
sugar. In this study, micropropagation and in vitro mutagenesis of this natural herb was
successfully conducted. It was found that shoot tips on MS medium supplemented with 1 mg/l
Kinetin showed the highest shoot induction and multiplication after 3 weeks of culture
(5.50±1.95a). Radiosensitivity test was conducted to identify the dose that killed 50% of the
irradiated explants (LD50) for in vitro stevia shoots and to select effective doses to be used for the in
vitro mutagenesis. Shoot tips were irradiated with acute and chronic gamma radiation at 0, 10, 20,
30, 40, 60, and 80Gy. At 60 Gy and 80 Gy, all treated shoot tips were not survived. In this study,
LD50 for the stevia was estimated at 29 Gy for acute irradiation and 45 Gy for chronic irradiation.
The effective doses were selected at 10, 20, 30 and 40 Gy. These selected doses were applied for the
in vitro mutagenesis of the stevia shoots
The research on radiation induced mutation has been conducted as one of the promising method of plant breeding in Malaysia since 1980s. Nuclear Malaysia is leading research institute inMalaysia conducting plant mutationbreeding research. Gamma Greenhousefacility located in Nuclear Malaysiais one of the irradiation facilitiesto serve as a chronic irradiation facility for inducing mutation in various organisms including plants, fungi and microbes.Chronic irradiation refers to the exposure of materials at a lower dose rate over a long period of time. Previous studies have shown that this type of irradiation can minimize radiation damages to living materials and produces a wider mutation spectrum, therefore is very useful for trait improvements in irradiated organisms. Experiments on induce mutation using Gamma Greenhouse facility for crop improvement program have been conducted since its first operation in 2009. Various plant species including ornamental and herbal plants, food crops and industrial crops have been irradiated to improve their traits such as higher yield and biomass, pest and disease tolerance, higher bioactive compounds, longer bloom time and many others. Most of these crop improvement programs were done through collaborations with other agencies in Malaysia such as universities, research institutes and government departments. A number of publications on crop improvement using Gamma Greenhouse have been published inlocal and international journals as well as seminar presentations at national and international levels. The outputs from induced mutation via chronic radiation using Gamma Greenhouse could be of great interest for plant breeders dealing with improvement and development of new cultivars. This paper discusses the activities and achievement in plant breeding and improvement using Gamma Greenhouse Facility in Malaysia.