Current range characteristics of Swiss stone pine (Pinus cembra L.) along the Carpathians revealed by chloroplast SSR markers.

We investigated the diversity pattern of nine Swiss stone pine (Pinus cembra L.) populations along the Carpathian range including the High Tatras, by using six chloroplast DNA microsatellites (cpSSR). Our aim was to detect genetically distinct regions by clustering of populations, and to tackle possible historical colonization routes. Our analysis referred to an investigated geographical range with the two most distant populations situated at about 500 air km. We found that the most diverse populations are situated at the two edges of the investigated part, in the Retezat Mts. (South Carpathians) and the High Tatras, and diversity decreases towards the populations of the Eastern Carpathians. Hierarchical clustering and NMDS revealed that the populations of the South Carpathians with the Tatras form a distinct cluster, significantly separated from those of the Eastern Carpathians. Moreover, based on the most variable chloroplast microsatellites, the four populations of the two range edges are not significantly different. Our results, supported also by palynological and late glacial macrofossil evidences, indicate refugial territories within the Retezat Mts. that conserved rich haplotype composition. From this refugial territory Pinus cembra might have colonized the Eastern Carpathians, and this was accompanied by a gradual decrease in population diversity. Populations of the High Tatras might have had the same role in the colonizing events of the Carpathians, as positive correlation was detected among populations lying from each other at a distance of 280 km, the maximum distance between neighbouring populations

Black Locust (Robinia pseudoacacia L.) Root Cuttings: Diversity and Identity Revealed by SSR Genotyping: A Case Study

Background and Purpose: Black locust (Robinia pseudoacacia L.) is a valuable species native to North America and today widely planted throughout the world for biomass production. In Hungary, where Robinia has great importance in the forest management, the clones have been selected for plantations on good, medium and poor quality sites. To conserve the identity, superior clones are vegetatively propagated by root cuttings. At times the collection of root cuttings can cause uncertainty for clonal identity because of the overlap of roots from neighboring plants. This can occur especially when the repository is damaged from severe environmental accidents and the planting layout has been lost. The aim of this study has been to verify by molecular markers the diversity or identity of black locust clones by root cuttings harvested in a damaged trial. Materials and Methods: Root cuttings of 91 clones belonging to five cultivars were collected in a trial severely damaged by storms and flooding periods. The obtained plantlets were analyzed with nine microsatellite (SSR) markers and the genetic identity/diversity within and among the plants was tested using the software GenAlEx version 6. Results: Multilocus genotypes (MLG) and the Paetkau’s assignation test (1985) revealed genetic variability among the samples: the analyzed plantlets were grouped in four classes instead of the five expected. In addition, 6 unique genotypes have been detected. Conclusions: This study remarks problems that may arise during the harvest of Robinia’s root cuttings, especially when the planting layout has been confused. Molecular analyses can be successfully used to control the germplasm before its sale as guaranty for nurseries, farmers and stakeholders

Nemesnyár klónok faanyagtani jellemzőkhöz köthető génjeinek genetikai változatossága = Allelic variation in candidate genes associated with wood properties of cultivated poplars

A nemesnyárak kiemelkedő gazdasági jelentőséggel bírnak. A bemutatott vizsgálat legfőbb célja egy olyan kutatási metodika ismertetése, amely a faanyag tulajdonságaiért felelős kulcsenzimek kódoló régióinak azonosításából indul ki, bemutatva a genomikai alapokra helyezett nemesítési technológiákban rejlő lehetőségeket. A vizsgálatunk első szakaszában 24 különböző, a faanyagképződés szempontjából releváns enzim kódoló régiójára terveztünk primerpárokat. Összesen 55 saját fejlesztésű primerpárt teszteltünk, 47,27%-os sikerességgel. Ezután nyolc enzimet választottunk ki részletesebb elemzésre hét nyárfaj és 11 hibrid klón bevonásával, összesen 23 nyár genotípus vizsgálata révén. A kiválasztott enzimek egy része a lignifikáció folyamatában vesz részt (COMT, CCoAOMT, SAMS), egy másik csoport a K+-függő xylogenezis során tölt be kulcsszerepet (Kt, ptk2, SKOR), míg a harmadik csoport (endo-1,4-b-xylanase, Araf-ase) a mikrofibrilla szög alakulásához köthető. A sikeresen amplifikált és azonosított 13 markerrégió révén összesen 188 szekvenciát elemeztünk és 90 SNP-t azonosítottunk. Értékeltük a polimorf helyek számát, a nukleotid diverzitást, az inszerciók/deléciók számát, az SNP-k típusát, a rekombinációs események minimális számát, illetve azonosítottuk a konzervatív szakaszokat. Eredményeink bemutatása során részletesen tárgyaljuk a vizsgálatban rejlő alkalmazási lehetőségeket

Life after disturbance (II): the intermediate disturbance hypothesis explains genetic variation in forest gaps dominated by Virola michelii Heckel (Myristicaceae)

International audienceKey message: Genetic diversity appears to be unaffected by disturbance in a stand of the light-demanding Neotropical treeV. michelii. Although spatial genetic structure is modified in post-disturbance cohorts, mixing of seeds from different mother trees in canopy gaps appears to efficiently maintain genetic admixture. Context: The interplay between genetic and demographic processes has major consequences on population viability. Population size affects demographic trends, while genetic diversity insures viability by reducing risks of inbreeding depression and by maintaining adaptive potential. Yet, the consequences of increases in census size (as opposed to effective size) on genetic diversity of forest populations are poorly known. Aims: We have studied the structure of genetic diversity in populations of saplings of the light-responsive tree, Virola michelii (Myristicaceae, the nutmeg family), in two plots having undergone different levels of canopy-gap opening disturbance. This allowed us to test the “intermediate disturbance” hypothesis, which generally applies to species diversity, at the intra-specific scale. Methods: Levels and distribution of genetic diversity were compared between plots and between life stages. Sapling parentage was analysed to infer each adult tree’s contribution to regeneration. Results: Genetic diversity was higher, and spatial genetic structure was stronger in the post-disturbance than in the control seedling population. Parentage analysis suggested that a limited number of parents contributed to most of the regeneration, but that efficient mixing of their progeny may have enhanced the diversity of saplings occupying canopy gaps. Conclusion: A mixture of demo-genetic processes may contribute to maintain genetic diversity in spite of, or possibly due to, ecosystem disturbance in V. michelii

Current range characteristics of Swiss stone pine (Pinus cembra L.) along the Carpathians revealed by chloroplast SSR markers

We investigated the diversity pattern of nine Swiss stone pine (Pinus cembra L.) populations along the Carpathian range including the High Tatras, by using six chloroplast DNA microsatellites (cpSSR). Our aim was to detect genetically distinct regions by clustering of populations, and to tackle possible historical colonization routes. Our analysis referred to an investigated geographical range with the two most distant populations situated at about 500 air km. We found that the most diverse populations are situated at the two edges of the investigated part, in the Retezat Mts. (South Carpathians) and the High Tatras, and diversity decreases towards the populations of the Eastern Carpathians. Hierarchical clustering and NMDS revealed that the populations of the South Carpathians with the Tatras form a distinct cluster, significantly separated from those of the Eastern Carpathians. Moreover, based on the most variable chloroplast microsatellites, the four populations of the two range edges are not significantly different. Our results, supported also by palynological and late glacial macrofossil evidences, indicate refugial territories within the Retezat Mts. that conserved rich haplotype composition. From this refugial territory Pinus cembra might have colonized the Eastern Carpathians, and this was accompanied by a gradual decrease in population diversity. Populations of the High Tatras might have had the same role in the colonizing events of the Carpathians, as positive correlation was detected among populations lying from each other at a distance of 280 km, the maximum distance between neighbouring populations

Wood Anatomical Traits Reveal Different Structure of Peat Bog and Lowland Populations of Pinus sylvestris L. in the Carpathian Region

Ecologically extreme habitats at a species’ distribution edges bear significance for biota under adverse climatic conditions and climate change. Range-edge populations adjust their functional traits to the special local ecological conditions, leading to increased intraspecific variability in their morpho-anatomical structure and, consequently, favor population survival in the absence of competitors. On the basis of wood anatomical traits, such as tracheid lumen area (CA), cell wall thickness (CWTrad), cell diameter-to-radial cell wall thickness ratio (CD/CWT), and the number of tracheids in the radial tracheid files (TNo), we investigated the xylem adjustment of Pinus sylvestris L. populations from six ecologically extreme habitats from the Eastern Carpathians and the Pannonian Basin. Results indicated significant differences among all studied sites in case of all wood anatomical traits as signs of the local adaptation of trees. Peat bog populations adapted their wood anatomical traits to the generally hydric, cool and anaerobic conditions of the peat bogs, exhibiting smaller CA and proportionally thick CWTrad to ensure the hydraulic safety of the stem, whereas, on the lowland site, trees were characterized by a more effective water-conducting system, developing larger CA with relatively thin CWTrad with lower carbon-per-conduit-costs at the expense of higher vulnerability to cavitation. Radial tree ring growth and TNo also differed markedly among sites, following the temperature and groundwater constraints of the habitats. Wood anatomical variability among tree rings and the corresponding short-term climate response of populations differed from the adaptive responses of the trees to the ecological characteristics of the habitat. In addition to the different phylogeographic origin evidenced in former studies, phenotypic differentiation by the habitat type of the studied populations linked to the variance in morpho-anatomical traits have contributed to the survival of the peripheral Scots pine populations at the species’ range margins

Szárazságtűrésben szerepet játszó SNP-k azonosítása kocsánytalan tölgy populációkban : alapkutatási eredmények a fenntartható tölgygazdálkodásért = Identification of SNP markers responsible for drought tolerance in sessile oak populations : results of basic research for sustainable oak management

Állományalkotó fafajaink genetikai állományban fellelhetőek az alkalmazkodási folyamatok lenyomatai, amelyek fontos ismereteket szolgáltathatnak a klímaadaptációt segítő erdőművelési stratégiák meghatározásához. Jelen kutatásunk során 18 közép- és délkelet-európai kocsánytalan tölgy [Quercus petraea (Matt.) Liebl.] populáció egyedeiben kimutatott SNP-k (egypontos nukleotid eltérések) és zárvatermő növények genomjában meghatározott, szárazságtűréssel kapcsolatba hozható szekvenciák kocsányos tölgy (Quercus robur L.) referencia genomra történő térképezését végeztük el, meghatározva így azon SNP-k csoportját, amelyek kapcsolatba hozhatók a szárazsági stresszválaszban szerepet játszó folyamatokkal. A kiugró FST értékkel bíró marker lókuszok és összesen 94 klimatikus változó bevonásával végzett regresszióanalízis során 16 erősen szignifikáns kapcsolatot mutattunk ki egyes génhelyek és néhány, csapadék vagy hőmérséklet alapú környezeti változó között. A szárazság szelekció alatt álló SNP-k kimutatása számos további, a fenntartható tölgygazdálkodást megalapozó kutatás alapját képezheti a jövőben. = The genetic information concerning the adaptation of main tree species to different environmental conditions could provide considerable knowledge to determine forest management responses to climate change. In the present study, we carried out a parallel mapping of SNP markers revealed in 18 Middle- and Southeast-European sessile oak [Quercus petraea (Matt.) Liebl.] populations and EST sequences of stress-responsive loci downloaded from an EST repository to determine the group of those SNPs, which are associated with the genetic background of adaptation processes in oaks. Regression analysis revealed 16 significant correlations between four outlier SNP loci representing high FST values and 94 climatic variables. All variables with significant correlations were found to be related to precipitation or temperature. The stress-responsive loci identified in this study may serve as a basis for common research to support future sustainable management of sessile oak in Hungary