Search results for "forest"
showing 10 items of 3780 documents
Chromosomal variation and genome size support existence of cryptic species of Triatoma dimidiata with different epidemiological importance as Chagas …
2006
Summary The wide geographical distribution of Triatoma dimidiata, one of the three major vectors of Chagas disease, ranges from Mexico to northern Peru. Since this species occupies a great diversity of artificial and natural ecotopes, its eradication is extremely difficult. In order to assist control efforts, we used chromosome analyses and DNA amount as taxonomic markers to study genetic variability in populations of T. dimidiata from Mexico, Guatemala, El Salvador and Colombia. We differentiated three groups or cytotypes defined by characteristic chromosome C-banding patterns and genome size measured by flow cytometry. The three cytotypes are restricted to different geographic locations. …
Genetic Diversity, Population Size, and Fitness in Central and Peripheral Populations of a Rare Plant Lychnis viscaria
1999
: Genetic diversity is expected to decrease in small and isolated populations as a consequence of bottlenecks, founder effects, inbreeding, and genetic drift. The genetics and ecology of the rare perennial plant Lychnis viscaria (Caryophyllaceae) were studied in both peripheral and central populations within its distribution area. We aimed to investigate the overall level of genetic diversity, its spatial distribution, and possible differences between peripheral and central populations by examining several populations with electrophoresis. Our results showed that the level of genetic diversity varied substantially among populations ( Hexp = 0.000–0.116) and that the total level of genetic …
Genomic basis of drought resistance inFagus sylvatica
2020
In the course of global climate change, central Europe is experiencing more frequent and prolonged periods of drought. These drought events have severe and detrimental impacts on the forest ecosystem. The drought years 2018 and 2019 affected European beeches (Fagus sylvatica L.) in noticeably different ways: even in the same local stand, badly drought damaged trees immediately neighboured apparently healthy trees. This led to the hypothesis that the genotype rather than the environment was responsible for this conspicuous pattern. We used this natural experiment to study the genomic basis of drought resistance in a Pool-GWAS approach. Contrasting the extreme phenotypes, we identified 106 si…
Resistant management of Bt corn and sustainability in Italy
2006
The Resistant Management (RM) of Bt corn in US requires 20% refuge area planted with non transgenic maize to preserve susceptible individuals of the pest. In Europe, especially in Italy, different considerations are necessary when RM plans are to be applied. In fact, when determining the size of the refuge areas other aspects around the transgenic corn, such as the surface of co-existing plans and other crops, must be considered. ECB is a polyphagous insect and its biology must be taken into account in the RM, especially in Italy where several crops and natural areas exist close to each other, and where field surfaces are clearly smaller than in the US. An important aspect of RM is the dete…
Development of “universal” gene-specific markers from Malus spp. cDNA sequences, their mapping and use in synteny studies within Rosaceae
2009
The Rosaceae contains many economically valuable crop genera, including Malus (apple), Fragaria (strawberry), and Prunus (stone fruit). There has been increasing interest in the development of linkage maps for these species, with a view to marker-assisted selection to assist breeding programs and, recently, in the development of transferable markers to permit syntenic comparisons of maps of different rosaceous genera. In this investigation, a set of Malus cDNA sequences were downloaded from the European Molecular Biology Laboratory database. The sequences were aligned with homologous full-length Arabidopsis genomic DNA sequences to identify putative intron–exon junctions and conserved flank…
Proposal of a Genome Editing System for Genetic Resistance to Tomato Spotted Wilt Virus
2014
Viruses provoke considerable economical losses in agriculture. New molecular approaches to develop genetic resistance based on translational genomics and precision genetic modifications are highly expected. The type II Clustered, Regularly Interspaced Palindromic Repeats (CRISPR) system including Cas9 nuclease represent a promising and very powerful tool to specifically modulate the expression and activity of genes involved in biotic stress responses. In this study, we describe an approach to develop a platform system based on CRISPR system for genome editing technology in tomato. Tomato is an excellent plant for this approach considering the high-quality genome sequence, the rapid life cyc…
Intra-allelic variation in introns of the S13-RNase allele distinguishes sweet, wild and sour cherries
2010
The cherry (Prunus avium), a self-incompatible diploid species, and the sour cherry (Prunus cerasus), a self-incompatible or self-compatible allotetraploid species derived from P. avium and Prunus fruticosa, share several S-RNase alleles, including S13. An inactive form, S13° ,i s found in some sour cherries. Two (AT) microsatellites are associated with allele S13-RNase, one in the first intron and one in the second. Their length polymorphisms were studied in 14 sweet and 17 wild cherries (both P. avium) and in 42 sour cherries. Fluorescent primers amplifying each microsatellite were designed and amplification prod- ucts sized on an automated sequencer. Variants ranged from 247 to 273 bp fo…
Gully erosion susceptibility mapping using GIS-based multi-criteria decision analysis techniques
2019
Abstract This research introduces a scientific methodology for gully erosion susceptibility mapping (GESM) that employs geography information system (GIS)-based multi-criteria decision analysis. The model was tested in Semnan Province, Iran, which has an arid and semi-arid climate with high susceptibility to gully erosion. The technique for order of preference by similarity to ideal solution (TOPSIS) and the analytic hierarchy process (AHP) multi-criteria decision-making (MCDM) models were integrated. The important aspect of this research is that it did not require gully erosion inventory maps for GESM. Therefore, the proposed methodology could be useful in areas with missing or incomplete …
Informational analysis of forest landscape spatial heterogeneity
1999
Summary Under the perspective of forest ecosystem management, landscape is interpreted as a functioning structure. From an inventory and monitoring operational point of view, such an approach implies wise use of geographic information systems and remote sensing techniques enabling a global view of the territorial mosaic. From a methodological point of view, landscape ecology theory may be used as the assessment framework. Remotely sensed data provide excellent opportunities for the involved analyses, using both vegetation density measures and spatial statistics. The objective of this paper was to assess landscape spatial heterogeneity using an analysis method based on Shannon's information …
Caracterización, Inventariación y aplicación del método de Valoración Biogeográfica de paisajes vegetales (LANBIOEVA) a la comarca de Collsacabra (Gi…
2018
The study presented in this paper takes part of a research project (LANBIOEVA: Landscape Biogeographic Evaluation) carried out for the past 25 years and it is, for now, its last stage. It’s a global landscape valuation method focused on vegetation as a main element of different units that can be evaluated. So far, the use of this method has resulted in numerous works: books, articles, book chapters, communications and presentations, and it has been applied in the study of different temperate and boreal regions of Europe and America. The method has been applied in the study and assessment of diverse vegetation landscapes of the Collsacabra shire (Girona). The objective is to verify its effec…