Advances of native and non-native Antarctic species to in vitro conservation: improvement of disinfection protocols

Abstract

Plants that inhabit Antarctica have raised scientific interest due to their resilience to climate change, abiotic tolerance mechanisms and potential biological applications. In vitro propagation is useful for conservation, genetic material availability of these species and avoiding mass collection in their habitat. In vitro culture protocols for the native plants Colobanthus quitensis and Deschampsia antarctica and the non-native Juncus bufonius have been affected by endophytic microorganisms that proliferate when introduced to tissue cultures. This study evaluated the microbicidal and phytotoxic effect of calcium hypochlorite (ca(clo) 2), silver nitrate (AgNO 3) and silver nanoparticles (AgNPs), and their use at different concentrations for different time periods. The Ca(ClO) 2 at 100 mg mL −1 showed the best microbial contamination control in D. antarctica (applied for 20 min) and for the three C. quitensis populations (applied for 15 min). In J. bufonius, AgNO 3 at 10 mg mL −1 for 10 min reduced the microbial growth, but oxidative damage was generated. AgNPs did not prevent contamination or have adverse effects on tissues. Survival plantlets from each treatment, population or species were effectively introduced to the tissue culture and their propagation was successful. these results constitute a fundamental advance for the introduction, propagation and conservation of Antarctic species and their use in scientific research. Global loss of biodiversity has increased considerably in recent years, which has made implementing conservation strategies essential for preserving and propagating plant genetic resources in each geographical region 1-3. One method of conservation is through the use of germplasm banks, or facilities and centers created to conserve genetic resources under favorable conditions to prolong their survival; the final objective is the ex-situ conservation of specific genetic diversity. They are a source of material that enables many possibilities for a species of interest, from developing new cultivable varieties, biological technologies, or to establishing ecological restoration plans 4. The Antarctic continent is an extreme ecosystem due to its adverse environmental conditions. Its organisms are exposed to restricted availability of water and nutrients, very low temperatures, frequent freezing and thawing cycles, prolonged periods of darkness in the winter and exposure to high UV radiation levels during summer. These environmental characteristics are inhospitable to most organisms that live in temperate areas 5. In addition, the increase in human activity in the region, and the confirmation that Antarctica is one of the critical points of global warming, make it a continent of highest priority for the conservation and development of multinational and multidisciplinary scientific challenges 6,7. There are only two native flowering plants that have been able to colonize some ice-free areas in the Antarctic Peninsula: Deschampsia antarctica Desv. (Poaceae) and Colobanthus quitensis (Kunth.) Bartl....

Calcium Oxalate Crystals in Leaves of the Extremophile Plant Colobanthus quitensis (Kunth) Bartl. (Caryophyllaceae)

“…In contrast, the Conguillío plants presented the largest shoots and leaves but also the narrowest leaves. Thus, the morphological characteristics showed by the ecotypes agree with those obtained by Cuba-Díaz et al (2017), where the Conguillío and Arctowski (Antarctic) populations presented the most contrasting anatomical traits, and the Punta Arenas and La Parva ecotypes showed intermediate-sized structural features [17].…”

“…La Parva and Punta Arenas plants showed intermediate values. These obtained results agreed with the south-north gradient pattern studied by Cuba et al (2017)[17], where the southernmost populations have smaller morphological traits.…”

“…Furthermore, significant differences in crystal accumulation between ecotypes were also observed (Figure 2b). [17], where the southernmost populations have smaller morphological traits. Different letters represent statistically significant differences between provenances (One-way ANOVA; p < 0.05).…”

“…Previous studies using C. quitensis populations from a latitudinal gradient showed that the ecotypes maintain their geographical characteristics even in controlled cultivation conditions in a common garden [ 16 ]. Furthermore, the high-latitude populations and low-latitude populations generally presented the most contrasting anatomical traits [ 17 ]. Therefore, these trait variations within the populations correspond to ecotypic genetic adaptation rather than phenotypic plasticity.…”

Content of biogenic and toxic elements in the leaves of Deschampsia antarctica É. Desv. (Poaceae): a preliminary study

“…is one of two flowering plants native to the Antarctic, and therefore it was intensively studied for decades. Most studies were concerned with D. antarctica adaptations to the harsh conditions of the Antarctic and its genetic and molecular aspects (Gidekel et al, 2003;Chwedorzewska et al, 2008;Parnikoza, 2019), phylogeography and evolution (Fowbert & Lewis Smith, 1994;Chiapella, 2007;Fasanella et al, 2017), in vitro conservation (Cuba-Díaz et al, 2020). D. antarctica is a perennial plant with origin not clearly known yet; however, most of the studies conclude that Antarctic vascular plant…”