The Effects of Light and Temperature on Germination of Stevia (Stevia rebaudiana BERT.) Seeds

Abstract

Abstract:The Stevia rebaudiana (Bert.) Bertoni is a perennial herbaceous plant and belongs to family of Asteraceae (Compositae). The contents of S. rebaudiana (Bert.) Bertoni consist mainly non-caloric stevioside and rebaudioside A sweeteners. Low seed germination is an important problem in stevia cultivation. Therefore in this study, the effects of light and temperature on germination performance of stevia seeds were studied. Stevia rebaudiana seeds were treated with two lights (light/darkness) and four different temperatures (15 ºC, 20 ºC, 25 ºC, 30 ºC). For each treatment, 50 seeds were counted and placed into petri dishes. Experiments were conducted as a randomized complete design method with three replicates. Germination was started within 6 to 10 days depending on the treatments. The highest seed germination rate (71%) was observed in darkness/25 ºC temperature and followed by darkness/20 ºC (68%) and light/25 ºC (67%). On the other hand, the lowest seed germination rate (31%) was obtained from 15 ºC in both light and dark conditions and followed by darkness/30 ºC (43%) and light/30 ºC (49%). The results showed that lower (15 ºC) and higher (30 ºC) temperatures significantly decreased the germination rates of stevia independently from the light treatments.

<i>Stevia rebaudiana</i> (Bert) Bertoni: regression models with mixed effects for investigating seed germination data

“…The increased odds of abnormal seedlings result from the effects of light in chemical reactions of seeds damaged by rain water and insect attacks. Therefore, light is an essential fixed factor for investigating the germination of Stevia rebaudiana seeds under controlled conditions, which corroborates the findings reported in the literature (Abdullateef & Osman, 2011;Simlat et al, 2016;Uçar et al, 2016). Random effects from seed lots, otherwise, will be significant when the next lots will detain the estimates of variability with a high probability of being found within the confidence intervals indicated in Table 2.…”

“…Seed lots produced under field conditions have lower percentage of seed germination than seed lots harvested under glasshouse conditions (Carneiro & Guedes, 1995;Takahashi et al, 1996) when pollination was controlled by bees and where recent estimates have frequently exceeded 80%. The current estimates were in part higher than reported in the literature (Abdullateef & Osman, 2011;Abdullateef et al, 2015;Simlat et al, 2016;Özyğit et al, 2015;Uçar et al, 2016), where the influence of sources of light was studied, but lower than responses from our laboratory recorded soon after 1990, where the seeds had been produced under the protected environment of the glasshouse (Carneiro & Guedes, 1992;Carneiro, 1996). In fact, the germination of fruit-like seeds in the current experiment also explains our lower results, but they were necessary to exclude factors like physical damage to the seed embryo when the pappus is mechanically removed, although this method does not filter out seeds with immature embryos, which also reduces the estimates from the seed lots.…”

Kecepatan Multiplikasi Tunas Tiga Aksesi Stevia (Stevia rebaudiana (Bertoni)) Secara In Vitro

“…Keterbatasan ini perlu diimbangi dengan metode perbanyakan yang cepat, baik melalui biji maupun setek. Perbanyakan melalui biji terbatas karena daya kecambah biji Stevia yang rendah dan merupakan masalah dalam budidaya Stevia (Ucar et al, 2016). Hasil penelitian Miyazaki and Watanabe (1974), bahkan melaporkan daya berkecambah benih stevia sangat rendah yakni kurang dari 10%, sehingga perbanyakan stevia lebih banyak dilakukan secara vegetatif dengan menggunakan stek batang.…”

Morpho-Physiological Responses of Stevia (Stevia Rebaudiana Bertoni) to Various Priming Treatments Under Drought Stress

“…Stevia (Stevia rebaudiana Bert. ), a member of the Asteraceae (Compositae) family, is an herbaceous perennial and short-day species (Yadav et al, 2011;Ucar et al, 2016). Naturally, this plant grows between 22-24° south and 53-56° west in South America (Paraguay and Brazil), where it is called ka'ahe'ê (or sweet herb) (Lemus-Mondaca et al, 2012).…”

“…The sweetness of the stevia plant is related to the presence of ent-kaurene-type diterpene glycosides (stevioside and rebaudiosides), which can be 300 times sweeter than sucrose (Hajihashemi and Ehsanpour, 2014;Aghighi Shaverdi et al, 2018). Since the sweet herb has self-incompatible flowers, its pollination is probably carried out by insects and wind (Ucar et al, 2016;Shahverdi et al, 2017). As a result, stevia produces often few pollinated flowers which have low germination percentage and poor establishment (Yadav et al, 2011;Lemus-Mondaca et al, 2012 capacity of stevia continues to be a major impediment for the plantation of this plant on a large-scale (Abdullateef et al, 2015).…”