Impact studies from different factors on root development from Stevia rebaudiana bertoni

The demand for an alternative and a high potency sweetener to substitute sugar increases year in year out, more so as a high percentage of the world population becomes increasingly diabetic. The alternative natural sweetener at hand has been Stevia rebaudiana Bertoni, a plant species, native to Paraguay and a member of the family compositae. Stevia is usually propagated by stem cuttings due to low percentage (10 %) seed germination, thus limiting large scales cultivation. To cultivate this crop en mass therefore, there is need to evolve efficient rooting techniques. Influences of irradiation from light, and hormones on rooting have been reported. The rooting efficacy in stem cuttings of this crop under varying light wavelengths, dark and hormone factors was investigated. Evaluated parameters include- (i) day of root emergent, (ii) percentage of rooted cuttings, (iii) average number, (iv) length and (v) width, of roots. Analysis of variance at p<.05 revealed that the number, length and width, of roots differed significantly in each case at p<0.000. Light irradiation was highly effective and a necessary factor for rooting in stems cuttings of this crop. The red light-IBA combined factors served best in stem micro-cutting practice and facilitation of effective mass cultivation in stevia crop

Effects of visible light wavelengths on seed germinability in Stevia rebaudiana Bertoni

Stevia rebaudiana Bertoni is one of 154 members of the genus Stevia and it produces sweet steviol glycosides .It originated from Paraguay. The leaves were used as general sweetening agent. Seed germination in Stevia isgenerally very low and constituted major obstacle to large scale production of the crop. Different wavelengths from visible light were tested on germination of Stevia seeds. The two lights used were (i) white light - 400 to 700nm, and (ii) red light - 660nm. Parameters evaluated include (i) Mean time germination, (ii) mean daily germination, (iii) germination rate, (iv) daily germination speed and (v) germination value. Multivariate tests at probability level <.05 revealed that daily germination speed and number of germinated seeds were significantly higher at (< .001) and (< .014) respectively with the effect of red light on seed germination. Red light (660nm) had better influence on germination in Stevia seeds than white light (400-700nm) and control experiment

Influence of genetic variation on morphological diversity in accessions of Stevia rebaudiana Bertoni

Stevia rebaudiana, a non caloric natural sweetener is currently the available substitute to sugar. It is a genus of about 150 species of herbs and shrubs, a Compositae and a native to Paraguay. The aim of this study was to evaluate collected accessions of stevia and characterize their genetic divergence. In 2010, 10 stevia accessions were collected across different locations in Malaysia. At maturity they were evaluated using morphological parameters and collected data were subjected to‘t’ test analysis at p<.05 as follows-(i) Plant heights: MS012 & SBK were significant at p<.001 and p<.002 respectively. (ii) Number of branches: BGI & SBK were significant at p<.001 and p<.008 respectively.(iii) Number of corymbs: AZI was significant at p<.000, while BGI was significant at p<.033. (iv) Number of leaves: MS012 & MS007 were respectively significant at p<.000 and p<.008. (v) Plant leaf size: AZI was significant at p<.003, MS007 at p<.005, and MS012 at p<.019 and (vi) stem girth: MS012 & MRG were also significantly different at p<.000 and p<.001 respectively. MSO12, MS007 & SBK had loads of promising genetic traits in studied accessions

Effects of stem cutting types, position and hormonal factors on rooting in Stevia rebaudiana Bertoni

Stevia rebaudiana Bertoni, a compositae, originated from Paraguay. It is propagated by stem cuttings. Leaves’ glycosides are about 300 times sweeter than sugar and safe for diabetic patients. In Malaysia, techniques for stevia mass production are limited. Varieties MS012 and MS007 obtained from MARDI were studied. For each variety, cuttings made were: (i) young apical shoot (ii) old apical shoot and (iii) non apical shoot. They were treated with six concentrations of IBA ranging from 1.9 to 2.5mM, and were placed in micro cutting chambers with the control. Characters studied were: (i) number of days for rooting, and (ii) root number at emergence. Analysis of variance revealed there were significant differences between characters at probability level p < 0.05. Cuttings from young apical shoots of MS012 and MS007 rooted on 5th day with root number ranging from 2.8 to 13.8. IBA 2.3mM was optimal. Young apical cuttings of either variety treated with the IBA 2.3mM were ideal