Geographical diversity and genetic relationships among Cedrus species estimated by AFLP

Molecular ecology resources, 2014

We combined restriction site associated DNA sequencing (RADseq) using a hypomethylation-sensitive enzyme and messenger RNA sequencing (mRNAseq) to develop molecular markers for the 16 gigabase genome of Cedrus atlantica, a conifer tree species. With each method, Illumina(®) reads from one individual were used to generate de novo assemblies. SNPs from the RADseq data set were detected in a panel of one single individual and three pools of three individuals each. We developed a flexible script to estimate the ascertainment bias in SNP detection considering the pooling and sampling effects on the probability of not detecting an existing polymorphism. Gene Ontology (GO) and transposable element (TE) search analyses were applied to both data sets. The RADseq and the mRNAseq assemblies represented 0.1% and 0.6% of the genome, respectively. Genome complexity reduction resulted in 17% of the RADseq contigs potentially coding for proteins. This rate was doubled in the mRNAseq data set, sugge...

Tree Genetics & Genomes, 2014

Plant Systematics and Evolution, 2011

Endemic island plant species with a narrow distribution are often, but not always, linked to low genetic variation within populations and a lack of differentiation among populations. Cedrus brevifolia is a narrow endemic island tree species of Cyprus. Its range is restricted to a single forest, divided into five neighbouring sites. This study, using biparentally inherited nuclear microsatellites and paternally inherited plastid (chloroplast) microsatellites, assessed the genetic variation of C. brevifolia within its sole population and the level of genetic differentiation among formed sites. The results from both markers showed high diversity (nuclear H T = 0.70; plastid H T = 0.93), strongly suggesting that the species did not experience severe bottleneck events or extensive genetic drift. Besides, the maintenance of a high genetic diversity in C. brevifolia may suggest that it originates from a widespread congener species. Significant genetic differentiation at nuclear (G ST = 0.052) and plastid (G ST = 0.119) markers was found among the formed sites. Remarkably, the relatively high genetic differentiation found at plastid markers was comparable to values observed in two widespread congener cedar species. The genetic differentiation probably occurred due to fragmentation of a previously uniform population. This would lead to the shaping of different genetic groups (Bayesian analysis) and to significant population substructure. Furthermore, significant values observed for both isolation by distance and large-scale spatial genetic structure could indicate ineffective gene flow among sites and the early geographical isolation of the more isolated sites from the core population.

Plants

Plant records reveal remarkable evidence about past environments and human cultures. Exploiting dental calculus analysis and using a combined approach of microscopy and gas chromatography mass spectrometry, our research outlines dietary ecology and phytomedicinal practices of the ancient community of Motya (Sicily, eight to sixth century BC), one of the most important Phoenician settlements in the Mediterranean basin. Micro-remains suggest use or consumption of Triticeae cereals, and animal-derived sources (e.g., milk and aquatic birds). Markers of grape (or wine), herbs, and rhizomes, endemic of Mediterranean latitudes and the East, provide insight into the subsistence of this colony, in terms of foodstuffs and phytotherapeutic products. The application of resins and wood of Gymnosperms for social and cultural purposes is hypothesized through the identification of Pinaceae secondary metabolites and pollen grains. The information hidden in dental calculus discloses the strong human-...

Frontiers in Ecology and Evolution

This study reconstructs and interprets the changing range of Atlas cedar in northern Morocco over the last 9,000 years. A synthesis of fossil pollen records indicated that Atlas cedars occupied a wider range at lower elevations during the mid-Holocene than today. The mid-Holocene geographical expansion reflected low winter temperatures and higher water availability over the whole range of the Rif Mountains relative to modern conditions. A trend of increasing aridity observed after 6,000 years BP progressively reduced the range of Atlas cedar and prompted its migration toward elevations above 1,400 masl. To assess the impact of climate change on cedar populations over the last decades, we performed a transient model simulation for the period between 1960 and 2010. Our simulation showed that the range of Atlas cedar decreased by about 75% over the last 50 years and that the eastern populations of the range in the Rif Mountains were even more threatened by the overall lack of water availability than the western ones. Today, Atlas cedar populations in the Rif Mountains are persisting in restricted and isolated areas (Jbel Kelti, Talassemtane, Jbel Tiziren, Oursane, Tidighine) that we consider to be modern microrefugia. Conservation of these isolated populations is essential for the future survival of the species, preserving polymorphisms and the potential for population recovery under different climatic conditions.

Frontiers in Ecology and Evolution

The five mediterranean-type climate (MTC) regions of the world, notable for their globally significant levels vascular plant diversity and endemism, fall into two groups. The Cape Region of South Africa and southwestern Australia are ancient and relatively climatically and tectonically stable landscapes with very high species richness relative to their area. This richness reflects a core of paleoendemic lineages as well as Neogene diversification. In contrast, California, the Mediterranean Basin, and central Chile are young climatically and tectonically dynamic landscapes that have developed significant floras in the Neogene. This relative pattern of species richness breaks down when only conifers are considered. Collectively the five MTC regions have a conifer flora of 122 species, almost 20% of the global total, and are rich in endemic conifers species. This diversity is heavily centered in California with 58 species (31 endemic) and the Mediterranean Basin with 40 species (32 endemic). The key to success of conifers in the Northern Hemisphere MTC regions has been the evolution of functional hydraulic traits associated with cold and/or drought tolerance, as exemplified by Neogene diversification in many clades of Pinaceae and Cupressaceae, and by ecophysiological traits that offer competitive advantages over angiosperms on oligotrophic soils. Podocarpaceae and many other Southern Hemisphere conifer lineages never developed equivalent traits and were poorly adapted to surviving increasingly cool and strongly seasonal climate regimes with associated aridity in the late Neogene. Because of extinctions, conifer lineages in the Southern Hemisphere today exhibit a significantly older distribution of divergence ages than their counterparts in the Northern Hemisphere and are home to many isolated relict taxa. This can be seen well in Chile and the Cape Region where there has been little or no Neogene diversification of conifers and a preponderance of relict Gondwanan lineages remain. Only Callitris in southwestern Australia among the Southern Hemisphere MTC floras has been able to evolve successful ecophysiological traits to adapt to aridity in a fire-prone environment and diversify. Traits of cold, drought, and low nutrient tolerance of Northern Hemisphere conifers, most notably in the Pinaceae, have led to their widespread introduction in Southern Hemisphere agroforestry.

Natural Product Communications

In the present study, the heartwood and the sapwood of a thick wood disc from a dated Cedrus brevifolia trunk, and the resin were analyzed for their volatile components. All samples were subjected to headspace solid-phase microextraction followed by gas chromatography mass spectrometry analysis. The main constituents were β-himachalene (22.2 %) in heartwood and (25.0 %) in sapwood, and α-pinene (37.8 %) in resin.

2020

Himalayan cedar (Cedrus deodara) is one of the most important temperate timber species of Western Himalayas and is considered to be among the endangered conifer species in the region. Knowledge of genetic diversity and population structure will help guide gene conservation strategies for this species. Ten polymorphic chloroplast microsatellites (cpSSR) were used to study genetic diversity and population structure in twenty one natural populations of C. deodara throughout its entire distribution range in Western Himalayas. When alleles at each of the 10 loci were jointly analysed, 254 different haplotypes were identified among 1050 individuals. The cpSSRs indicate that C. deodara forests maintain a moderately high level of genetic diversity (mean h = 0.79 ). AMOVA analysis showed that most of the diversity in C. deodara occurs within populations. Bayesian analysis for population structure (BAPS) revealed spatial structuration of the variation (22 % of the total variation) and substru...

Life

Allopolyploidy is considered as a principal driver that shaped angiosperms’ evolution in terms of diversification and speciation. Despite the unexpected high frequency of polyploidy that was recently discovered in the coniferous genus Juniperus, little is known about the origin of these polyploid taxa. Here, we conducted the first study devoted to deciphering the origin of the only hexaploid taxon in Juniperus along with four of its closely related tetraploid taxa using AFLP markers with four primers combinations. Phylogenetic analysis revealed that the 10 studied species belong to 2 major clusters. J. foetidissima appeared to be more related to J. thurifera, J. sabina, and J. chinensis. The Bayesian clustering analysis showing a slight variation in genetic admixture between the studied populations of J. foetidissima, suggesting an allopolyploid origin of this species involving J. thurifera and J. sabina lineages, although a purely autopolyploidy origin of both J. thurifera and J. f...

Dendrobiology, 2023

This literature review focuses on the biology and ecology of Juniperus drupacea. Within the context of the series 'Our Forest Trees' by the Institute of Dendrology PAS at Kórnik, the following key topics are discussed: taxonomy with paleo-records, morphology, anatomy, geographical distribution, ecology (including habitat, communities, response to biotic factors and the environment, and phenology), disease, and conservation. Juniperus drupacea, also known as the Syrian juniper, is a dioecious evergreen gymnosperm found primarily in two distribution centers: one in the southern Peloponnese in Europe and the other in the mountains along the Mediterranean Sea in Southwest Asia. The populations from Europe and Asia differ genetically, biochemically, and morphologically. Juniperus drupacea is a medium-sized tree occurring in mountains, predominantly at elevations of 800-1400 m, on basic to moderately alkaline soils and even on calcareous rock. It is a component of fir, pine, cedar, and sometimes also juniper forest, rarely entering maquis. As with other junipers, it is a light-demanding, moderately frost-and drought-resistant, sometimes acting as an invader of abandoned fields and pastures. It is rarely grazed by goats. Its low palatability is a result of the high content of volatile oils in the needles and cones. The volatile oils have been extensively used in folk medicine and have been investigated for new medicinal uses. The species is rare, endangered and protected in Greece, parts of Turkey and Lebanon. Its ecological niche could potentially be reduced by global climate change.

International Journal of Forestry Research, 2022

Atlas cedar (Cedrus atlantica (Endl.) G. Manetti ex Carrière) is an endemic species in the mountains of North Africa that is attracting international interest in its use in the reforestation of degraded ecosystems. This study aims to investigate and evaluate the morphoanatomical characteristics of needles of four cedar populations localized in the Middle and High Atlas Mountains. Descriptive statistics, analysis of variance (ANOVA), descriptive power, scatter-plot of the discrimination function, scatter-plot of discrimination, and dendrogram of the closest Euclidean distances were made on traits. The results of the linear model of ANOVA nested as population and tree within population suggest the differences statistically significant for the traits measured at a different level. Among these traits, the length of the needle, the width of a vascular bundle including endodermis, and thickness of the wall of hypodermis cell revealed the highest discriminating characters among populations of C. atlantica from the Middle and High Atlas and between the populations of the Middle Atlas. The agglomeration of populations over short Euclidean distances also showed a higher level of differentiation between two ecotypes of C. atlantica not very geographically distant in the Atlas Mountains of Morocco. The ecotype belonging to Aït Oufella and Aït Ayach confers this species a place of choice in the projects of revalorization of the Mediterranean populations, especially in semiarid areas.