Effect of light conditions and ABA on cold storage and post-storage propagation of Taraxacum pieninicum

Monika Kamińska,Emilia Wilmowicz,Andrzej Tretyn,Alina Trejgell,Edyta Skrzypek

doi:10.1007/s11240-016-1026-1

Abstract

Taraxacum pieninicum is an extremely threatened species. It seems that traditional protection methods of this species are insufficient and it is necessary to use biotechnology tools that allow the in vitro storage of plant material. The present study describes in vitro conservation of T. pieninicum by slow-growth storage. Various light conditions and abscisic acid (ABA) treatments and combinations thereof were tested. Viability, proliferation rate and ability of shoots to root were evaluated during regrowth. Moreover, the effect of shoot storage conditions on the ABA level was analysed. The results showed that light during 3-months’ storage increased the level of endogenous ABA. Similar results were observed when storage at a low temperature was prolonged to 9 months. Changes in ABA level had a negative effect on shoot condition. However, these changes were related to leaves and did not affect the ability of shoot tips to proliferate after long-term storage. Addition of ABA to storage medium increased several folds the level of ABA in plant tissues, which resulted in a reduction in the visual rating and proliferation rate. Shoots obtained after post-storage regrowth were able to root. All rooted shoots survived adaptation to field conditions and were able to flower in the second year after acclimatization. The analysis of DNA content indicated that all the regenerants had the same ploidy level independent of treatments during storage. Cold storage of T. pieninicum as used in this study enabled the interval between subcultures to be extended to 9 months.

Highlights

Taraxacum pieninicum Pawł. (Asteraceae) is probably the oldest endemite of the Pieniny Mountains (Poland)
Shoot tips used in the experiment were the same size and healthy (Fig. 1a) and given a visual rating of 5 on establishment of culture, based on Reed’s scale, decreasing with the duration of storage
The addition of abscisic acid (ABA) to the medium led to lower value of the parameter

Summary

Introduction

Taraxacum pieninicum Pawł. (Asteraceae) is probably the oldest endemite of the Pieniny Mountains (Poland). The present population of T. pieninicum consists of two clusters of a small number of individuals. This species is listed as critically endangered (CR), and even as declining—critically endangered (E) on Polish red lists (Zarzycki and Szelag 2006; Wrobel and Zarzycki 2008). Protection of T. pieninicum involves constant monitoring of its natural habitat as well as protection of the gene pool in the Seed Bank of the Polish Academy of Sciences (PAS) Botanical Garden—Center for Biological Diversity Conservation (CBDC) in Powsin, Warsaw. It seems to be reasonable to develop a method of cultivating T. pieninicum at minimal growth conditions, which will lead to an increase in the intervals between subcultures and reduce the risk of changes in the genetic material

Objectives

Methods

Results

Discussion

Conclusion