The Silene mollissima (L.) Pers. aggregate is part of section Siphonomorpha Otth. and currently comprises 11 narrow endemic species of the Western Mediterranean Basin. Three of these taxa (S. velutina Pourr. ex Loisel, S. ichnusae Brullo, De Marco & De Marco f., and S. badaroi Breistr.) have a distribution range centred in the northern Tyrrhenian area and occurring in coastal habitats. Inter- and intra-specific variability in the responses to light, constant (5–25 °C) and alternating temperatures (25/10 °C), salt (NaCl, 0–600 mmol/L), and levels of nitrate (KNO3, 20 mmol/L) under salt stress, as well as recovery of seed germination were evaluated for these species to more effectively support their in-situ and ex-situ conservation. Our results highlighted that the seeds of these three taxa were nondormant, and that light significantly improved their rate of germination, which was higher (>80%) at low temperatures (5–15 °C) and under the alternating temperature regime (25/10 °C), but decreased significantly at the highest temperature tested (25 °C). Seeds from Silene velutina and S. ichnusae germinated in up to 300 mmol/L NaCl, and S. badaroi germinated in up to 100 mmol/L. For all of the species except S. badaroi, salt did not affect seed viability, and recovery germination did not decrease with increasing salinity and temperature. Interpopulation variability, both in salt tolerance and recovery germination, was detected for S. velutina. The addition of KNO3 did not affect germination or recovery germination under salt conditions. The lack of effect from KNO3 suggests that nutrient availability is not a requirement for seed germination in these species. Our results show that all species experience an optimum period of germination during autumn–winter, which is when water availability is highest and soil salinity levels are minimal because of the Mediterranean rainfalls, but seeds from S. velutina and S. ichnusae will germinate up until spring.
This article provides a comparison of the vascular alien flora of Sardinia (Italy) and that of Corsica (France), both territories belonging to the Western Mediterranean biogeographic subregion. The study has recorded 598 (90 doubtful) alien taxa in Sardinia (18% of the total flora) while 553 (87 doubtful) in Corsica (17%); six are new report to Sardinia and 27 to Corsica. A total of 234 taxa are common to both islands. Neophytes are 344 taxa (68% of the total) in Sardinia and 399 taxa (73%) in Corsica. The invasive component includes 64 taxa in Sardinia (13% of the alien flora) and 99 taxa (21%) in Corsica, 33 of them common to both territories. The total 740 alien taxa of Sardinia and Corsica are included in 93 families; being Fabaceae the richest. The comparison of the biological spectrum reveals that phanerophytes (202 taxa, 40%) are the most represented in Sardinia and therophytes (149 taxa, 32%) in Corsica. A study of the geographical origin shows supremacy of the American element in Sardinia (170 taxa, 34%) and in Corsica (136 taxa, 29%). The majority of taxa arrived as a result of intentional human introductions, mainly for ornamental use (247 taxa, 49% in Sardinia; 208 taxa, 45% in Corsica). Seminatural, agricultural and synanthropic are the most occupied habitats. These data show the need for joint action to stem the increasingly worrying phenomenon of the alien flora in order to reduce the negative effects on natural habitats and native flora.
Rouya polygama (Apiaceae) is an endangered Mediterranean species of great phytogeographical and ecological interest, growing on coastal sandy dunes. Intraspecific variability in the responses to constant temperatures (5-25°C) and an alternating temperature regime (25/10°C), salt stress (0-600A mM NaCl) and recovery of seed germination was evaluated among six populations from Sardinia and Corsica. Seeds were non-dormant and germination percentages ranged from 10 to 83%, depending on temperature and population. Differences in germination percentages were mainly due to different seed mortality among seed lots. R. polygama seeds germinated in salt concentrations up to 200A mM NaCl, whereas higher salt concentrations totally inhibited germination. Salt affected seed viability, and the recovery response decreased with increasing salinity and temperature. Inter-population variability and different sensitivity to NaCl in seed germination were detected. Our results are consistent with field germination in a period from autumn to spring, when water is available in the soil and temperatures are not prohibitive for seedling establishment, representing an advantageous ecological adaptation for seedling establishment to the unpredictable Mediterranean rainfall pattern. Further studies on R. polygama are needed to investigate germination requirements at temperatures higher than 25°C and its germination in the field, and to clarify genetic inter-population variability, considering a higher number of populations and possibly extending to North African populations
This study reveals contrasted dynamics of orchid communities between local and regional scales in Corsica. Although high turnover in communities was found at the local scale, regional species richness was maintained despite major land-use changes. Conserving landscape mosaics could provide locally suitable habitats for orchids of different ecologies to maintain diversity at larger spatial scales.
Plant leaves host species rich communities of foliar endophytic fungi (FEF). Compared to the other compartments of the plant microbiome, FEF diversity is poorly known. Here we document the communities of FEF associated with the endemic Corsican pine Pinus nigra subsp. laricio at three sites across its natural range and examine the effect of forest site, tree age and light exposure on FEF composition. Metabarcoding using next-generation sequencing provided 8,243,608 Ascomycota ITS2 sequences clustered into 642 FEF operational taxonomic units (OTUs). FEF communities did not differ in species richness across sites and tree cohorts, but differed in composition among forest patches and according to tree age. FEF community composition did not correlate with needle location (shade vs full light). Results are robust against the various options of the bioinformatic pipeline specifically developed. This study provides the first picture of FEF diversity in a Mediterranean island and underlines the complementarity of forest massifs for fungal conservation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.