Ex situ conservation of endangered Limonium species in the Bulgarian flora

Abstract

A B S T R A C TNative populations of endemic, rare and threatened Limonium species (L. meyeri, L. bulgaricum, L. latifolium, L. vulgare, L. asterotrichum and L. gmelinii) in Bulgaria were monitored and found seriously declined. To preserve these wild genotypes, an approach involving in vitro propagation of explants isolated from immature inflorescence stems was applied at the Institute of Ornamental Plants, Sofia. The rooted plantlets produced were acclimated and grown outdoors under an optimized cultivation regime, which resulted in the establishment of an ex situ plantation. Plant performance ex situ (determined by leaf rosette diameter, plant height and the number of flower stems) was substantially improved and the variation in the biometric indices was found remarkably lower than in natural environment. The developmental stages of ex situ plants appeared with a delay in relation to their onset in the native environment, but occurred synchronously within each species. Analysis of germination of seeds harvested from ex situ and in situ grown plants showed species-specific behaviour, but in general, seed vitality remained relatively low in laboratory conditions, in the soil and in vitro. In order to assess the potential for protecting the native Limonium species from uncontrolled harvesting, the possibility for the production of cut flowers in ex situ conditions was studied. High yield of cut flowers from ex situ plants in comparison with the potential yield from the wild plants and extended vase life in comparison with commercially produced Limonium sinuatum were obtained. The results demonstrated that the applied micropropagation and agrotechnique for protected cultivation are reliable tools for ex situ conservation of the endangered Limonium genotypes in the Bulgarian flora. In addition to its advantage as a rescue measure, the developed system was shown to be suitable for obtaining cut flowers of competitive market quality.

Limonium dagmarae (Plumbaginaceae), a new species from Namaqualand coast, South Africa

“…Ex situ conservation using tissue cultures, as applied in the case of L. sinensis (Dam et al 2010) or being developed in Bulgaria (Kaninski et al 2012), seems like a feasible option to enhance survival of the species. Etymology:-Named in honour of Dagmar Mucina, the life partner and wife of the first author, in recognition of her indispensable support and her shared passion for the flora of Namaqualand.…”

Application of In Vitro Plant Tissue Culture Techniques to Halophyte Species: A Review

“…When starting from seeds, problems of dormancy may also require additional treatments such as scarification with sulfuric acid (H 2 SO 4 ) [ 90 , 123 ], seed coat removal [ 96 ] or longitudinal cut for Distichlis spicata [ 104 ]. The seeds of Limonium species were stratified in sealed and moistened plastic bags at 4 °C during 45 days before decontamination [ 96 ]. Growth regulators such as kinetin (Kin) and gibberellic acid (GA 3 ) promote seed germination for Plantago species [ 92 , 93 ].…”

“…Another study with S. brachiata showed that the addition of 20 g/L MgCl 2 to double-concentrated MS medium with 0.5 mg/L NAA significantly improved the rooting efficiency [ 63 ], whereas S. europaea rooted better on half-strength MS with activated charcoal and a combination of IBA and Kin [ 64 ]. During in vitro rooting of L. monopetalum , the tolerance to NaCl concentrations up to 10 g/L was observed but the root number was reduced as the NaCl concentration increased [ 96 ]. The effect of sucrose content on Eryngium species was analyzed, and E. maritimum had the highest root number with MS/2 with 1.5% sucrose and 0.1 mg/L IAA [ 73 ].…”

Estimating vegetative reproduction and population size of Saussurea esthonica

“…During the past decades increasing attention has been focussed on ex situ conservation of rare plant species, and in vitro, seed bank and field collections of endangered plants have been created (Dubova et al 2010;Kaninski et al 2012;Miranto et al 2012;Cristea et al 2013). However, in situ conservation remains to be one of the fundamental methods of species protection.…”