(Cryo)conservation of Ajania pacifica (Nakai) Bremer et Humphries shoot tips via encapsulation-dehydration technique.

　　BACKGROUND: Ajania pacifica, a novelty on the horticultural market, is valued as an ornamental and a medicinal plant. Breeding programs led to the creation of numerous cultivars. Therefore, it is important to develop species storage methods. OBJECTIVE: The aim of this study has been to develop an encapsulation-based cryopreservation protocol of Ajania pacifica shoot tips. MATERIALS AND METHODS: Shoot tips of ajania 'Bengo' were precultured on media with different sucrose and ABA concentrations, encapsulated and dehydrated for various periods and stored in liquid nitrogen. After thawing the explants were inoculated on different recovery media. RESULTS: A higher (9%) sucrose concentration and addition of ABA (15 µM) during preculture, followed by 4-hour desiccation (41% moisture content), as well as the application of cytokinins (1.11 µM BA or 1.16 µM KIN) in the post-thawing recovery medium were necessary to provide a high survival rate of ajania 'Bengo' shoot tips. CONCLUSION: Despite good survival of shoot tips of ajania following cryopreservation procedure, the stimulation of their further growth is a problem.

Morphological and genetic distinctiveness of metallicolous and non-metallicolous populations of Armeria maritima s.l. (Plumbaginaceae) in Poland.

Patterns of morphological, genetic and epigenetic variation (DNA methylation pattern) were investigated in metallicolous (M) and non-metallicolous (NM) populations of Armeria maritima. A morphological study was carried out using plants from six natural populations grown in a greenhouse. Morphological variation was assessed using seven traits. On the basis of this study, three representative populations were selected for molecular analyses using metAFLP to study sequence- and methylation-based DNA variation. Only one morphological trait (length of outer involucral bracts) was common to both metallicolous populations studied; however, the level of variation was sufficient to differentiate between M and NM populations. Molecular analyses showed the existence of naturally occurring epigenetic variation in A. maritima populations, as well as structuring into distinct between and within population components. We show that patterns of population genetic structure differed depending on the information used in the study. Analysis of sequence-based information data demonstrates the presence of three well-defined and genetically differentiated populations. Methylation-based data show that two major groups of individuals are present, corresponding to the division into M and NM populations. These results were confirmed using different analytical approaches, which suggest that the DNA methylation pattern is similar in both M populations. We hypothesise that epigenetic processes may be involved in microevolution leading to development of M populations in A. maritima.

Armeria maritima from a calamine heap--initial studies on physiologic-metabolic adaptations to metal-enriched soil.

Plants of Armeria maritima are found both on unpolluted sites and on soils strongly polluted with heavy metals. Seedlings of A. maritima from a zinc-lead calamine heap in ore-mining region (Boleslaw population) and from unpolluted area (Manasterz population) were tested to determine the zinc, cadmium and lead tolerance. In hydroponic experiments Boleslaw population was more tolerant to zinc, cadmium and lead. Localization of heavy metals in roots was determined using the histochemical method for detecting metal-complexes with dithizone. Their accumulation was found in root hairs, rhizoderma and at the surface of the central cylinder. Glutathione level in plants increased after metal treatment of both populations. However, its high level was not correlated with phytochelatin production. These metal-binding complexes were not detected in plants exposed to zinc, cadmium or lead. Changes of organic acids concentrations in Armeria treated with metals may suggest their role in metal translocation from roots to shoots. The content of organic acids, especially malate, decreased in the roots and increased in the leaves. These changes may be important in Pb-tolerance of Manasterz population and in Zn-, Cd-tolerance of calamine population from Boleslaw.