Raffaello Giannini

Allozyme, chloroplast DNA and RAPD markers for determining genetic relationships between Abies alba and the relic population of Abies nebrodensis

Allozyme, chloroplast (cpDNA) and random amplified polymorphic DNA (RAPD) markers have been used to estimate genetic and taxonomic relationships among different populations of Abies alba and the relic population of A. nebrodensis. Twelve isozyme gene loci, as well as restriction fragment length polymorphism (RFLP) at cpDNA spacer regions between t-RNA genes were analysed. Moreover, a set of 60 random sequence 10-mer primers were tested. Over all isozyme loci, evident differences in allele frequencies among A. nebrodensis and A. alba populations were found, particularly at 2 loci, phosphoglucose isomerase (Pgi-a) and shikimate dehydrogenase (Skd-a). More than 10% of the total genetic diversity was due to differences among populations. High values of genetic distances among populations were also found. Out of the 60 primers tested, 12 resulted in a polymorphic banding pattern both within and among populations. A total of 84 RAPD fragments were produced by the 12 selected primers. A phenogram of relationships among populations was constructed based on RAPD band sharing: the differentiation of the A. nebrodensis population was evident. The analysis of molecular variance (AMOVA) was used to apportion the variation among individuals within populations and among populations. There was considerable variation within each population: even so, genetic divergence was found among populations. This pattern of genetic variation was very different from that reported for inbred species. Identical cpDNA amplification and restriction patterns were observed among all the individuals sampled from the populations. Taken together, the results of allozyme and RAPDs show a clear differentiation among A. nebrodensis and A. alba populations and provide support for their classification into two different taxonomic groups.

Unexpected presence of Fagus orientalis complex in Italy as inferred from 45,000-year-old DNA pollen samples from Venice lagoon

BackgroundPhylogeographic analyses on the Western Euroasiatic Fagus taxa (F. orientalis, F. sylvatica, F. taurica and F. moesiaca) is available, however, the subdivision of Fagus spp. is unresolved and there is no consensus on the phylogeny and on the identification (both with morphological than molecular markers) of Fagus Eurasiatic taxa.For the first time molecular analyses of ancient pollen, dated at least 45,000 years ago, were used in combination with the phylogeny analysis on current species, to identify the Fagus spp. present during the Last Interglacial period in Italy.In this work we aim at testing if the trn L-trn F chloroplast DNA (cpDNA) region, that has been previously proved efficient in discriminating different Quercus taxa, can be employed in distinguishing the Fagus species and in identifying the ancient pollen.Results86 populations from 4 Western Euroasistic taxa were sampled, and sequenced for the trn L-trn F region to verify the efficiency of this cpDNA region in identifying the Fagus spp.. Furthermore, Fagus crenata (2 populations), Fagus grandifolia (2 populations), Fagus japonica, Fagus hayatae, Quercus species and Castanea species were analysed to better resolve the phylogenetic inference.Our results show that this cpDNA region harbour some informative sites that allow to infer relationships among the species within the Fagaceae family. In particular, few specific and fixed mutations were able to discriminate and identify all the different Fagus species.Considering a short fragment of 176 base pairs within the trn L intron, 2 transversions were found able in distinguishing the F. orientalis complex taxa (F. orientalis, F. taurica and F. moesiaca) from the remaining Fagus spp. (F. sylvatica, F. japonica, F. hayataea, F. crenata and F. grandifolia). This permits to analyse this fragment also in ancient samples, where DNA is usually highly degraded.The sequences data indicate that the DNA recovered from ancient pollen belongs to the F. orientalis complex since it displays the informative sites characteristic of this complex.ConclusionThe ancient DNA sequences demonstrate for the first time that, in contrast to current knowledge based on palynological and macrofossil data, the F. orientalis complex was already present during the Tyrrhenian period in what is now the Venice lagoon (Italy).This is a new and important insight considering that nowadays West Europe is not the natural area of Fagus orientalis complex, and up to now nobody has hypothesized the presence during the Last Interglacial period of F. orientalis complex in Italy.

Geographic distribution of chloroplast variation in Italian populations of beech (Fagus sylvatica L.)

The distribution of chloroplast DNA (cpDNA) variation in Italian beech (Fagus sylvatica L.) populations was studied using PCR-RFLP and microsatellite markers. In total, 67 populations were analysed, and 14 haplotypes were identified by combining the two marker types. A remarkable subdivision of cpDNA diversity in Italian beech was found, as indicated by a high level of genetic differentiation (Gst=0.855). The highest level of total haplotype diversity (ht=0.822) was estimated for southern Italian populations. The highest number of haplotypes was found in the central-southern region of the peninsula. The nested clade analysis provided evidence for past fragmentation events that may have been occurred during the Quaternary glaciations and had a major role in defining the genetic structure of the central-southern Italian beech populations. Only one haplotype apparently spread towards the north of Italy along the Apennine chain and reached the Italian slope of the western part of the Alps (Maritime Alps, Liguria). All haplotypes found along the Apennines remained trapped in the Italian peninsula. Southern and central Italy represent hotspots of haplotype diversity for Italian beech.

FONTE NOVELLO OLD-GROWTH FOREST

The study has been carried-out to compare the genetic diversity between oldgrowth beech forest and post-harvested naturally regenerated stands. The purpose was also the evaluation of the possible genetic impact of harvesting systems; these information are needed for the development sustainable silvicultural methods

Effects of climate change on the genetic diversity of forest trees. Significance and uncertainties

Abstract The predicted rise in the atmospheric concentration of greenhouse gases is expected to induce a global climate change, which would effect the genetic diversity of forest tree populations. Genetic diversity is briefly analyzed in its components and the processes responsible of its conservation are outlined. The role of genetic diversity in determining plant and ecosystem adaptability to environmental changes is discussed. No direct data are available yet on the effects of climate change on genetic diversity of forest tree populations; suggestions are therefore drawn from the comparison with other anthropogenic disturbances. The importance of the conservation of an heterogeneous environment and of migration pathways is stressed.

SELVICOLTURA: BIODIVERSITÀ, RISORSE GENETICHE, AREE PROTETTE E FAUNA

Viene presentata una sintesi delle principali tematiche affrontate nella sessione «Selvicoltura, biodiversita, risorse genetiche, aree protette e fauna». I contributi hanno riguardato in particolare la variabilita genetica nelle piante forestali, il monitoraggio della biodiversita attraverso criteri e indicatori quali il legno morto, la frammentazione degli habitat forestali, la ricolonizzazione forestale di terreni ex-coltivi o pascoli, i sistemi di classificazione dei boschi per tipi forestali, la rinaturalizzazione dei sistemi forestali semplificati, in particolare rimboschimenti, alcune forme di uso del bosco legate ai saperi locali, la caratterizzazione e gestione degli habitat Natura 2000, la gestione forestale all’interno dei Parchi Nazionali, la «questione ungulati», i rapporti fra selvicoltura e fauna ornitica. Si conclude che la conservazione della biodiversita non puo prescindere dal riconoscere la complessita degli ecosistemi forestali e dei loro rapporti con la realta sociale, economica e culturale con cui interagiscono.

Il pensiero di Aldo Pavari nel campo della genetica forestale

Il lavoro descrive l’opera condotta da Pavari nel campo della genetica forestale in Italia. In particolare, si sottolinea l’importanza dell’attivita sperimentale sulle razze e provenienze di alcune delle principali specie di interesse forestale italiane, sull’individuazione di soprassuoli per la raccolta del seme, sullo studio dei caratteri giovanili degli alberi, sulle tecniche di ibridazione artificiale.

Silviculture: biodiversity, genetic resources, protected areas and fauna

The Authors synthesize the main themes discussed in the Session “Silviculture, biodiversity, genetic resources, protected areas, and fauna” of the Third Italian National Congress of Silviculture. Attention was focused on genetic variability of forest trees, criteria and indicators for forest biodiversity monitoring, forest habitat fragmentation, forest recolonization of pastures and open areas, forest type classification, renaturalization of simplified forest systems, in particular plantations, forest management systems based on traditional local knowledge, characterization and management of Natura 2000 forest habitats, forest management in National Parks, relationship between silviculture and wild ungulates. The Authors conclude that forest biodiversity conservation must take into account both the complexity of forest ecosystems and of their interactions with the social, economic and cultural environment.