Biochemical Markers of Salt Stress in European Larch (Larix decidua)

[EN] Larix decidua, the European larch, does not grow in natural saline areas, but it can be affected by salinity either by the common practice of winter de-icing of mountain roads with NaCl, or when grown as an ornamental tree in urban areas by the use of low quality, salinised irrigation water. In the present study, the responses to salt stress of young seedlings obtained from seeds of seven Carpathian larch populations were analysed. After 30 days of treatments with 150 mM NaCl, growth and biochemical parameters were determinated. Salt stress inhibited growth of all seedlings, as shown by the relative reduction of stem length and fresh weight, and induced significant changes in the needle levels of several biochemical stress markers. Seedlings from all populations showed a marked reduction of photosynthetic pigments contents and an increase of proline and malondialdehyde (MDA) concentrations. Under salt stress, plants accumulated Na+ and Cl- in the needles, whereas K+ was maintained at a steady level. Responses of seedlings from the different populations were similar, with only small quantitative differences that did not allow the identification of more salt tolerant genotypes. However, the study revealed that several of the biochemical markers mentioned above can be suitable for the rapid and non-destructive assessment of the effects of salinity in European larch.Plesa, IM.; Al Hassan, M.; Sestras, A.; Vicente, O.; Boscaiu, M.; Sestras, R. (2018). Biochemical Markers of Salt Stress in European Larch (Larix decidua). Notulae Scientia Biologicae. 10(3):430-438. https://doi.org/10.15835/nsb10310322S43043810

Effects of Drought and Salinity on European Larch (Larix decidua Mill.) Seedlings

[EN] Larix decidua, the European larch, is not normally affected by drought or salinity in its natural habitats, but it may be when grown as an ornamental tree, by the widespread practice of winter de-icing of mountain roads with NaCl, and because of global warming-induced environmental changes. The responses of two-month-old larch seedlings to 30 days water deficit (withholding irrigation) or salt stress (150 mM NaCl) treatments were studied by determining stress-induced changes in several growth parameters and biochemical markers (ion and osmolyte contents, level of oxidative stress, activation of enzymatic and non-enzymatic antioxidant systems). Both treatments caused the inhibition of growth, degradation of photosynthetic pigments, a small increase in malondialdehyde (MDA, an oxidative stress biomarker), and the activation of antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR). In all cases, salinity appeared to have stronger effects on the seedlings than water deficit. The presence of relatively high concentrations of glycine betaine, both in control and stressed plants, may represent a constitutive mechanism of defence against stress in European larch. Additionally, other responses were specific for salt stress and included the activation of K+ transport from roots to shoots and the accumulation of Pro as an osmoprotectantI.M.P. and M.A.H. were recipients of Erasmus Mundus pre-doctoral scholarships financed by the European Commission.Plesa, IM.; González-Orenga, S.; Al Hassan, M.; Sestras, AF.; Vicente, O.; Prohens Tomás, J.; Sestras, RE.... (2018). Effects of Drought and Salinity on European Larch (Larix decidua Mill.) Seedlings. Forests. 9(6). doi:10.3390/f9060320S9

Highly informative SSR genotyping reveals large genetic diversity and limited differentiation in European larch (Larix decidua) populations from Romania

[EN] European larch (Larix decidua) is naturally distributed at high elevations in Central Europe. Romanian populations of L. decidua are scattered in different areas of the country. In this study, we used 12 highly informative genomic simple sequence repeat (SSR) markers for genotyping seven populations from different areas of Romania. The SSR markers were highly variable, with up to 11 alleles per SSR locus and an average polymorphic information content of 0.713. High values of observed (Ho = 0.542) and expected (He = 0.738) heterozygosities were observed. Cluster analysis of populations did not group them according to geographical distance, but some clusters contained populations from a similar altitudinal range. The partition of genetic variation revealed that two-thirds of the genetic variation was found within individuals (due to high Ho levels), while only one-sixth of the total genetic variation corresponded to variation among populations. A population structure analysis identified four genetic clusters, and in most cases individuals from a single population were assigned to several genetic clusters. Multivariate principal coordinates analysis confirmed the population structure analysis. SSR markers are a powerful tool for evaluating diversity, relationships, and the genetic structure of Romanian L. decidua populations, which have high levels of diversity and low genetic structurationPietro Gramazio is grateful to Universitat Politecnica de Valencia for a predoctoral contract (Programa FPI de la UPV-Subprograma 1/2013 call). Ioana M Plesa is grateful to the Doctoral School of the University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca and ICHAT - Institute of Advanced Horticulture Research of Transylvania, and Universitat Politecnica de Valencia, for their support. Mariola Plazas is grateful to Spanish Ministerio de Economia, Industria y Competitividad for a post doctoral grant within the Juan de la Cierva programme (FCJI-2015-24835).Gramazio, P.; Plesa, IM.; Truta, AM.; Sestras, AF.; Vilanova Navarro, S.; Plazas Ávila, MDLO.; Vicente, O.... (2018). Highly informative SSR genotyping reveals large genetic diversity and limited differentiation in European larch (Larix decidua) populations from Romania. Turkish Journal of Agriculture and Forestry. 42(3):165-175. https://doi.org/10.3906/tar-1801-41S16517542