The establishment of an in vitro gene bank in Dianthus spiculifolius Schur and D. glacialis ssp. gelidus (Schott Nym. et Kotschy) Tutin: I. The initiation of a tissue collection and the characterization of the cultures in minimal growth conditions

Abstract

In the last decades the plants have to cope with the warming of the climate. As a consequence of this process more than half of the plant species could become vulnerable or threatened until 2080. Romania has a high plant diversity, with endemic and endangered plant species, the measures of biodiversity conservation being necessary. The integrated approach of biodiversity conservation involves both in situ and ex situ strategies. Among ex situ methods of conservation, besides the traditional ones (including field and botanic collection and seed banks), in vitro tissues techniques offer a viable alternative. The germplasm collections can efficiently preserve the species (of economic, scientific and conservative importance), in the same time being a source of plant material for international exchanges and for reintroduction in the native habitats.The "in vitro gene banking" term refers to in vitro tissues cultures from many accessions of a target species and involves the collection of plant material from field or from native habitats, the elaboration of sterilization, micropropagation and maintaining protocols. These collections have to be maintained in optimal conditions, morphologically and genetically characterized. The aim of our work was to characterize the response of the plant material to the minimal in vitro growth protocol for medium-term cultures achievement as a prerequisite condition for an active gene bank establishment in two rare Caryophyllaceae taxa: Dianthus spiculifolius and D. glacialis ssp. gelidus. Among different factors previously tested for medium-term preservation in Dianthus genus, mannitol proved to be more efficient for minimal cultures achievement. In vitro, the cultures were evaluated concerning their growth, regenerability and enzyme activity (POX, SOD, CAT) as a response to the preservation conditions in the incipient phase of the initiation of the in vitro collection. The two species considered in this study showed a good in vitro behavior when using the mannitol as growth retardant.