&lt;b&gt;&lt;i&gt;Stevia rebaudiana&lt;/i&gt; (Bert) Bertoni: influence of osmotic stress and seed priming on seed germination under laboratory conditions

Keila Regina Hossa,José Walter Pedroza Carneiro,Terezinha Aparecida Guedes,Alessandro Lucca Braccini

doi:10.4025/actasciagron.v39i3.32951

<b><i>Stevia rebaudiana</i> (Bert) Bertoni: influence of osmotic stress and seed priming on seed germination under laboratory conditions

Keila Regina Hossa, José Walter Pedroza Carneiro + Show 2 more

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https://doi.org/10.4025/actasciagron.v39i3.32951

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Abstract

The foremost factor necessary for plant growers cultivating large acreages of Stevia rebaudiana (Bert) Bertoni is the production of qualitative bedding plants. The objective of this study was to evaluate the influence of osmotic-priming on the uniformity of seed germination. First, we evaluated the percentage of normal seedlings from two seed samples harvested in 2011 and 2012. The seeds harvested in 2012 produced 71.4% normal seedlings and thus they were used in the next experiments. The seeds were subjected to osmotic stress using five concentrations of polyethylene glycol (PEG-6000) at -0.2, -0.4, -0.6, -0.8, and -1.0 MPa in contrast with distilled water. Based on these first results, only -0.8 and -1.0 MPa were evaluated in the third experiment. The seeds were immersed in both concentrations of polyethylene glycol (PEG-6000) for imbibing at 20ºC for four, five, six, and seven days. Thereafter, we evaluated the time to the first normal seedling (Ti), time to the last normal seedling (Tf), percentage normal seedlings at the initial time (Pi) and percentage of normal seedlings at the end of every treatment (Pf). Osmotic priming increased the percentage of normal seedlings of the Stevia rebaudiana and reduced the time to the first and last germination events.

Highlights

Stevia rebaudiana (Bert) Bertoni is a short-day plant that produces many foliar steviol glycosides sweeter than sucrose (Yadav, Singh, Dhyani, & Ahuja, 2011; Brandle, Starratt, & Gijzen, 1998; Carneiro, 1990)
The industrial use of Stevia goes beyond the presence of sweeteners because glycosides, such as rubusoside, which is partially responsible for the sweet taste, have remarkable solubilizing properties that can be used by the pharmaceutical industry (Liu et al, 2011)
The highest percentage (71.4%) of germination was obtained from seeds harvested in 2012 in contrast to the normal seedlings (67.0%) from seeds harvested in 2011, and both samples were stored at 5°C under 20% relative humidity

Summary

Introduction

Stevia rebaudiana (Bert) Bertoni is a short-day plant that produces many foliar steviol glycosides sweeter than sucrose (Yadav, Singh, Dhyani, & Ahuja, 2011; Brandle, Starratt, & Gijzen, 1998; Carneiro, 1990). These non-caloric glycosides have been recommended for diabetic, overweight and obese patients requiring natural alternatives to artificial sweeteners, such as the industrial aspartame and saccharin The agro-industry of Maringá, v. 39, n. 3, p. 379-384, July-Sept., 2017

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