Dianthus diutinus KIT., EUROPEAN ENDEMISM CRITICALLY ENDANGERED WITH EXTINCTION: MULTIPLIED in vitro FOR THE CONSERVATION AND REPOLULATION OF ITS AREA OF ORIGIN

Dianthus diutinus Kit. is considered the most endangered species with extinction among all species from Dianthus variety. The present study has the purpose of multiplying in vitro this specie critically endangered, its maintenance in collections in vitro and the repopulation of some natural habitats or protected areas, with completely organised and vigorous neo-plantlets obtained through this method. The explant was made of juvenile bud detached from the inflorescence and cultivated in vitro on MS medium (Murashige and Skoog, 1962) with several environmental variants. After about 45 days there were analysed the culture conditions depending on which there were established: the capacity of in vitro conservation (regeneration %), the evolution in relationship with the nature of the specie, the vigorousness of the neo-plantlets obtained, the capacity of in vitro multiplication (%), and finally, the ex vitro acclimatisation of the neo-plantlets and the ecological reconstruction of the specie's area of origin. The value of the analysed parameters of Dianthus diutinus Kit. specie cultivated in vitro is determined by the presence in the culture medium of a cytokinin (BA - 1 mg/l) or of a natural extract (EP - 5 mg/l), and the differentiation of the radicular system, by the presence of auxin in small doses (AIA - 0.5 mg/l). There was followed also the maintenance of the specie in collections in vitro, through the application of some periodic subcultures (on simple mediums, without phytohormones) for avoiding the ageing of the neo-plantlets and the growth of their vigorousness. Ex vitro acclimatisation was applied depending on the calendar time of the growing moon, a time which along with the value of the neo-plantlets, their capacity of differentiating a vigorous radicular system, the intermediary stages, determined the acquirement of a good and very good survival percentage to outside conditions (75-90%).