Establishing climatic constraints shaping the distribution of alien plant species along the elevation gradient in the Alps

In this work, we analyse the role of climatic constraints in shaping the distribution of alien plant species along the elevation gradient in the European Alps. Alien species occurrence was recorded in 278 plots located beside rivers, from 100 to 2,100 m a.s.l. Climate variables were calculated from the data recorded by 145 meteorological stations and interpolated by a multiple regression approach. Both richness and occurrence of aliens were modelled. In particular, relationships between the occurrence of alien plants and (1) elevation or (2) the climatic variables, were tested by applying generalised linear models and generalised linear mixed models; the model parameters obtained were used to estimate upper elevation limits of alien occurrence and their related climate values. Sixty-eight alien species were encountered, the majority (71%) invasive in Italy and worldwide. A steep decrease in alien species richness with elevation was found, with the probability of alien species occurrence decreasing by half for each 100 m increase in elevation. Minimal adequate models based on (1) non-transformed climatic variables and (2) derived PCA values, confirmed that occurrence of alien plant species along the elevation gradient was positively related to the minimum temperature, the mean temperature and the heat sum for the spring season, rather than to the incidence of absolute minimum temperature and frost days, as usually assumed. Although further experimental analyses are needed, these results support the hypothesis that, referring to climate factors, elevation limits along rivers are mainly established by low spring temperatures which operate at the level of population viability rather than plant survival.     

Flora Palinologica Italiana. Schede diCorylus avellana L. cv. Tonda Gentile delle Langhe (TGL) eCorylus maxima Miller e valutazioni statistiche

Riassunto Si sono allestite le schede morfopalinologiche compilate secondo le norme della ?Flora Palinologica Italiana?, perCorylus avellana L. cv. TGL eCorylus maxima Miller per polline acetolizzato e fresco. Le due specie rivestono interesse agronomico anche per l'ottenimento di ibridi interspecifici. La differenza del rapporto P/E fra le due entità risulta altamente significativa Tuttavia non è possibile un riconoscimento dei due tipi pollinici direttamente in analisi aerosporologiche.

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Summary Palynological cards ofCorylus avellana cv. TGL andCorylus maxima Miller are presented for fresh and acetolyzed pollens, according to the project ?Flora Palinologica Italiana?. Both species are interesting from the agricultural point of view, also for the possibility to obtain interspecific hybrids. The difference of the P/E ratio between the two entities is highly significant. In sprite of this fact, is not possible to discriminate the two pollen types in aerosporological analysis for their extreme similarity.

     

AirborneCorylus pollen monitoring: Preliminary data

Summary In 1984–5 and 1985–6 aerosporological data were collected in an experimental hazel-nut orchard in Cravanzana (High Langa) whereCorylus maxima andCorylus avellana cv. Tonda Gentile delle Langhe (TGL) were present with a prevalence of the latter. Inter variety crosses withC. avellana and interspecific hybridsC. avellana xC. maxima were also present. CultivatedCorylus flowering diagrams are known, while more evidence is needed on the spread and concentration of airborne pollens, especially during female anthesis which spans over a month on average. Pollen release periods were identified including onset of accessory periods. Aerosporological data helped identify TGL association in relation to spread of plants and quality of nut. Cultivars and hybrids, which have already been studied in terms of genetic compatibility, have been considered in terms of airborne pollen periods. Thanks to adequate pollinators we can rationalize orchards, increase productivity while maintaining nut quality. This work has been supported by “Ministero della Pubblica Istruzione” found 60%.      

Radioimmune assay for the Xg(a) surface antigen at the individual red cell level

An indirect radioimmune assay has been successfully used for the detection of the Xg(a) antigen on the surface of individual human red blood cells. The assay requires only microvolumes of reagents, is highly sensitive, and is equally reliable with fresh blood samples and with red blood cells stored in liquid nitrogen. The method has been used to estimate the number of Xg(a) binding sites. It may be useful to screen for quantitative isoalleles, as well as to investigate the alleged lack of participation of the Xg-locus in the inactivation of the X-chromosome.     

Schede palinologiche diArtemisia vulgaris L.,Artemisia verlotorum Lamotte;Artemisia annua L., su campioni freschi e acetolizzati

Riassunto Sono state allestite le schede palinologiche diArtemisia vulgaris L.,Artemisia verlotorum Lamotte eArtemisia annua L. su polline fresco e acetolizzato. Le tre specie hanno interesse aerobiologico e allergologico. Vengono anche riportati dati sulla loro distribuzione in Italia, con particolare riferimento adArtemisia annua.      

Population genomics in Sardinia: a novel approach to hunt for genomic combinations underlying complex traits and diseases.

The availability of highly polymorphic markers permits testing whether complex traits and diseases result from genomic interactions between nonallelic normal variants at separate loci. Such variants may be identified by deviations from the expected distributions of alleles at a high number of polymorphic loci, when individuals with the phenotype of interest are compared to normal controls of the same breeding unit, provided that both groups share the same remote ancestry and had no ancestors in common for the last three to four generations. The circumstances needed for such studies are ideally met on the island of Sardinia. The recurrent finding of the same type of association in separate breeding units between the phenotype of interest and a given genotype should allow a distinction between true genetic identity by descent and randomly occurring identities, as these will be obviously different in separate breeding units. The availability of several breeding units located in sharply different ecological environments will permit assessment of the role of nature/nurture factors in the degree of manifestation of each newly discovered genotype/phenotype association. A pilot study to evaluate the proposed strategy has been carried out in the Sardinian village of Carloforte, a community of about 8,000 individuals who have remained genetically homogeneous. Fifty-five control samples have been genotyped with six tetranucleotide microsatellites and with a subset of the 400 markers contained in the ABI PRISM linkage mapping panel, version 2. The allele frequencies for these microsatellite markers have been determined for these 55 individuals and compared to those from a random sampling of subsets of these 55 persons. For the six tetranucleotide microsatellites, a subset of as few as 20 people displayed the same allele frequency distributions as observed with the original 55 unrelated individuals. In conclusion, when samples are chosen from the same breeding unit, the number of individuals sufficient to draw the genomic profile of an isolated population can be relatively small. Likewise, the number of probands with the phenotype of interest can be even smaller when they are ascertained with the same genealogical criteria as the normal controls. By comparing the genomic profile of the probands to a fraction of the control samples within each of several separate breeding units of common remote ancestry, the search for genotype/phenotype association for mono- and multifactorial traits and diseases should be simplified and yield unequivocal results.