Use of chlorine dioxide to sterilize medium for tissue culture of potato

Yongbo Duan,Jianping Xue,Mengchu Sun,Han Zhang,Tao Xue,Fenglan Zhao

doi:10.1038/s41598-019-46795-4

Abstract

In vitro cultured seedlings or microtubers are the major starting materials for the production of potato. Currently, seedlings are cultured in media sterilized by autoclaving, which, however, consumes more electricity and takes longer for sterilization, and also requires high temperature-tolerant vessel materials. In order to identify alternative methods of sterilizing culture conditions, the disinfection effects of chlorine dioxide (CD) at 88.0, 29.3, 17.6, 12.6 and 8.8 μM were evaluated in potato medium and vessels. The ≥12.6 μM gaseous CD effectively disinfected vessel through a 30-min fumigation process, and its aqueous solution disinfected potato medium efficiently as well. In presence of 12.6 μM CD in the medium, the potato seedlings had similar morphological features as those grown on autoclaved medium, with some exceptions. The use of 12.6–29.3 μM aqueous CD to sterilize the medium increased antioxidant enzyme activities in potato seedlings, while the use of higher concentration decreased antioxidant enzyme activity levels. SSR analysis did not reveal significant molecular differences in potato seedlings cultured between autoclaved and CD-sterilized medium. In addition to this, CD-sterilized medium induced potato microtuber formation at a similar rate as autoclaved medium. In summary, using CD to sterilize potato medium and vessels did not compromise the growth of seedlings and microtuber induction. This study provides an economical and simplified sterilization method for media used to culture potato plantlets, and this can improve energy use of the large-scale tissue culture industry.

Highlights

Potato (Solanum tuberosum L.) is a multipurpose crop and is the 4th most produced crop across the world, following the staple food grains wheat (Triticum aestivum), maize (Zea mays) and rice (Oryza sativa), possessing strategic importance to guarantee food security worldwide
Chemical sterilization of media has not been tested in potato tissue culture, despite the need for improved conditions to reduce the cost of producing microtubers
The effective concentration of gaseous chlorine dioxide (CD) to sterilize vessels using fumigation was minimum of 12.6 μM for 10 min, where longer or high concentrations of treatments were more effective. These results demonstrate that fumigating vessels with CD effectively inactivates microbes, similar to the results of glass surface sterilization via CD fumigation reported previously[20]

Summary

Introduction

Potato (Solanum tuberosum L.) is a multipurpose crop and is the 4th most produced crop across the world, following the staple food grains wheat (Triticum aestivum), maize (Zea mays) and rice (Oryza sativa), possessing strategic importance to guarantee food security worldwide. Autoclaving may degrade some chemicals in the culture media, or generate harmful substances, such as sucrose-derived aldehydes and phenols that can result from the catalysis of FeNa-EDTA during the high temperature sterilization process[8] For these reasons, different sterilization methods have been tested in plant tissue culture, such as the microwave oven[9], plant essential oils[10] and chemicals. We present the application of chlorine dioxide (CD) to disinfect potato culture medium and a comprehensive evaluation of seedlings cultured in media sterilized with CD at the phenotypic, physiological and molecular levels This method of sterilization may facilitate the use of pathogen-free materials in potato production by making the process economical, environmentally safe and simple

Methods

Results

Conclusion