TESTING OF CHRYSANTHEMUM STEM NECROSIS VIRUS AND OTHER AMERICAN CLADE 1 TOSPOVIRUSES BY RT-PCR

Detection of Chrysanthemum stem necrosis virus (CSNV) and other tospoviruses of American clade 1

The genetic consequences of population marginality

Aim: Marginal tree populations, either those located at the edges of the species\u27 rangeor in suboptimal environments, are often a valuable genetic resource for biologicalconservation. However, there is a lack of knowledge about the genetic consequencesof population marginality, estimated across entire species\u27 ranges. Our study ad-dresses this gap by providing information about several genetic indicators and theirvariability in marginal and core populations identified using quantitative marginalityindices.Location: Southwestern Europe and North Africa.Methods: Using 10,185 SNPs across 82 populations of maritime pine (Pinus pinasterAit.), a widespread conifer characterised by a fragmented range, we modelled therelationship of seven genetic indicators potentially related to population evolution-ary resilience, namely genetic diversity (based on both all SNPs and outlier SNPs),inbreeding, genetic differentiation, recessive genetic load and genomic offset, withpopulation geographical, demo-historical and ecological marginality (as estimated bynine quantitative indices). Models were constructed for both regional (introducinggene pool as a random factor) and range-wide spatial scales.Results: We showed a trend towards decreasing overall genetic diversity and increas-ing differentiation with geographic marginality, supporting the centre-periphery hy-pothesis (CPH). However, we found no correlation between population inbreedingand marginality, while geographically marginal populations had a lower recessive ge-netic load (only models without the gene pool effect). Ecologically marginal popula-tions had a higher genomic offset, suggesting higher maladaptation to future climate,albeit some of these populations also had high genetic diversity for climate outliers.Main Conclusions: Overall genetic diversity (but not outlier-based estimates) and dif-ferentiation patterns support the CPH. Ecologically marginal populations and those atthe southern edge could be more vulnerable to climate change due to higher climate maladaptation, as predicted by genomic offsets, and/or lower potentially adaptive ge-netic diversity. This risk is exacerbated by typically small effective population sizesand increasing human impact in marginal populations

Phytoplankton assemblage over a 14-year period in the Adriatic Sea: patterns and trends

Considering the role of phytoplankton in the functioning and health of marine systems, it is important to characterize its responses to a changing environment. The central Adriatic Sea, as a generally oligotrophic area, is a suitable environment to distinguish between regular fluctuations in phytoplankton and those caused by anthropogenic or climatic influences. This study provides a long-term perspective of phytoplankton assemblage in the central eastern Adriatic Sea, with 14 years of continuous time series data collected at two coastal and two offshore stations. The predominant phytoplankton groups were diatoms and phytoflagellates, but their proportion varied depending on the vicinity of the coast, as evidenced also by the distribution of chlorophyll a. In the coastal environment, the phytoplankton biomass was substantially higher, with a higher proportion of microphytoplankton, while small phytoplankton accounted for the majority of biomass in the offshore area. In addition, a decreasing trend in diatom abundance was observed in the coastal waters, while such trend was not so evident in the offshore area. Using a neural gas algorithm, five clusters were defined based on the contribution of the major groups. The observed increase in diversity, especially in dinoflagellates, which outnumber diatom taxa, could be a possible adaptation of dinoflagellates to the increased natural solar radiation in summer and the increased sea surface temperature