Polyhouse cultivation of invitro raised elite Stevia rebaudiana Bertoni: An assessment of biochemical and photosynthetic characteristics

Authors: LATA, HEMANT - University Of Mississippi; CHANDRA, SUMAN - University Of Mississippi; WANG, YANHONG - University Of Mississippi; ELSOHLY, MAHMOUD - University Of Mississippi; KHAN, IKHLAS - University Of Mississippi

Submitted to: Journal of Tropical Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2015
Publication Date: 12/26/2015
Citation: Lata, H., Chandra, S., Wang, Y., Elsohly, M.A., Khan, I.A. 2015. Polyhouse cultivation of invitro raised elite Stevia rebaudiana Bertoni: An assessment of biochemical and photosynthetic characteristics. Journal of Tropical Agriculture. 33(4):1-7. 2015

Interpretive Summary: Polyhouse cultivated Stevia rebaudiana Bertoni plants, initially raised from synthetic seeds, were assessed for biochemical and photosynthetic characteristics and compared with their mother plant. Well-developed in vitro regenerated plantlets were successfully acclimatized inside a climatic controlled growing room and finally cultivated under polyhouse conditions. Fully developed plants were compared with each other and with mother plant for their chlorophyll (Chl) and carotenoid (Car) contents, photosynthetic and water vapor exchange characteristics, and dulcoside A, rebaudioside A, rebaudioside D, steviobioside and stevioside content. Regenerated plants were highly comparable to mother plants in terms of their photosynthetic pigment contents and gas and water vapour exchange characteristics. High-performance liquid chromatography (HPLC), was used to analyze major secondary metabolites in Stevia plants. Dulcoside A, rebaudioside D and steviobioside content was found below the level of detection, whereas, no significant differences (p < 0.05) in rebaudioside A and stevioside content between the mother and regrown plants following four months of in vitro storage was observed. These results confirm clonal fidelity of S. rebaudiana plants derived from synthetic seeds following in vitro storage.

Technical Abstract: Polyhouse cultivated Stevia rebaudiana Bertoni plants, initially raised from synthetic seeds, were assessed for biochemical and photosynthetic characteristics and compared with their mother plant. Synthetic seeds were produced using nodal segments containing single axillary buds excised from in vitro proliferated shoots with 5% sodium alginate and 50 rnM CaCh. The synthetic seeds were stored at 25°C for 4 months and re-generated under the tissue culture conditions (16-h photoperiod, 25°C) on Murashige and Skoog (MS) medium supplemented with thidiazuron (TDZ 0.2mg/L). Well-developed in vitro regenerated plantlets were successfully acclimatized inside the climatic controlled growing room and finally cultivated under the polyhouse conditions. Fully developed plants were compared with each other and with mother plant for their chlorophyll (Chi) and carotenoids (Car) contents, photosynthetic and water vapor exchange characteristics and, dulcoside A, rebaudioside A, Rebaudioside D, steviobioside and stevioside content. Our data shows that regenerated plants were highly comparable to mother plants in terms of their photosynthetic pigment contents and gas and water vapour exchange characteristics. High­performance liquid chromatography (HPLC), was used to analyze major secondary metabolites in Stevia plants. Dulcoside A, Rebaudioside D and steviobioside content was found below the level of detection. Whereas, no significant differences (p < 0.05) in rebaudioside A and stevioside content between the mother and regrown plants following four months of in vitro storage was observed. These results confirm clonal fidelity of S. rebaudiana plants derived from synthetic seeds following in vitro storage.