Studies on Pollen Viability and Germinability in Accessions of Stevia rebaudiana Bertoni

Raji Akintunde Abdullateef,Nor Hafizah Zakaria,Nor Hazwani Hasali,Mohamad Osman

doi:10.5539/ijb.v4n3p72

Raji Akintunde Abdullateef, Nor Hafizah Zakaria + Show 2 more

Open Access

https://doi.org/10.5539/ijb.v4n3p72

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Abstract

Stevia rebaudiana produces sweet steviol glycosides extractable from the leaves. With zero calorie contents, it represented inevitable health diet for diabetic patients. Poor seed germination (10%) posed obstacles towards large scale establishment. Pollens play fundamental role in fertilization and seed sets. Studying pollen in vitro germination and growth of pollen tube are essential for explaining lack of fertility in spermatophytes. Limited studies exist on the pollen profile of this crop. Pollen viability and germinability in Stevia accessions MS007, MS012 and SBK were studied. 3000 pollen grains per accession were examined for viability. Evaluated parameter includes pollen staining ability in Cotton blue in lacto phenol. Boric acid concentrations (0.025 g, 0.05 g and 0.1 g) prepared with 20 g of sucrose in 100 ml distilled water were formulated into pollen germination medium (GM), 300 pollens per accession were scored for germinability. Analysis of variance revealed no significant difference with pollen viability at p<.424 among all the accessions; while though gernminabilty showed no significant difference at p<.478 and p<.246 for MS007 and MS012 respectively, the SBK differed significantly, with 0.1% treatment, at p<.000. The pollens were viable and possess germination ability. Optimum germination medium comprised 0.025g Boric acid. Poor seed germination in Stevia is unconnected with its pollen profile.

Highlights

Stevia rebaudiana Bertoni is a member of the genus Stevia and one of only two that produce sweet steviol glycosides (Soejarto et al, 1982; 1983)
Boric acid concentrations (0.025 g, 0.05 g and 0.1 g) prepared with 20 g of sucrose in 100 ml distilled water were formulated into pollen germination medium (GM), 300 pollens per accession were scored for germinability
We investigated the pollen grain viability and germinability levels in selected accessions of Stevia rebaudiana bertoni

Summary

Introduction

Stevia rebaudiana Bertoni is a member of the genus Stevia and one of only two that produce sweet steviol glycosides (Soejarto et al, 1982; 1983). Sessile, oppositely arranged lanceolate to oblancoelate in shape, and deeply or slightly serrated above the middle. Özbek (1993) reported that internal and external factors could limit pollen production, viability and germinability rates bringing about poor performance in fertilization and seed/fruit yield. High pollen quantity and quality profile are central to viable seed formation and propagation in seed plants. In Stevia rebaudiana there has been limited studies on the pollen grain profile, while the problem with poor seed germinability still persists. The inability to propagate this natural sweetener crop by seeds has been a major factor limiting large scale cultivation. We investigated the pollen grain viability and germinability levels in selected accessions of Stevia rebaudiana bertoni

Pollen Viability Studies

Pollen Germination Studies

Pollen Germinabilty Studies

Conclusion