Diversity between and within farmers’ varieties of tomato from Eritrea

Tomato yields in Eritrea are low (15 Mg/ha) compared with 19 Mg/ha in Africa and 27 Mg/ha worldwide. This is partly caused by poor quality of varieties used. This study analysed the diversity among and heterogeneity within farmers’ varieties of tomato from Eritrea and compared these varieties with other African and Italian varieties. Fifteen simple sequence repeat (SSR) markers were used for the genetic analysis. Genetic similarities among the varieties were calculated and an Unweighted Pair Group Method with Arithmetic Mean analysis was performed. Furthermore, individual plants of varieties were genotyped to evaluate uniformity within varieties. A high degree of diversity was observed among the Eritrean varieties. Thirteen out of the 15 SSRs were polymorphic, with 2 to 5 alleles per marker. The dendrogram showed two major types of varieties: San-Marzano and Marglob. Eritrean varieties were closely related to old Italian varieties in both types. Analysis of the within-variety variation showed that the Eritrean tomato genotypes were less uniform than the other varieties, probably because of deliberate mixing. A survey among farmers showed that some of them purposely mixed seeds to prolong the harvesting period, for yield stability and stress tolerance. Farmers value ‘new material’ as a source of influ

Grazing as a conservation management tool:Responses of voles to grazer species and densities

Grazing is a widely applied conservation management tool, but the optimal regime for biodiversity conservation is still unknown. The effects of grazers on small mammals are not yet fully understood and mostly restricted to studies which compare grazed with ungrazed areas. We determined the effect of different livestock grazers and densities and a rotation regime, on voles in a conservation area in The Netherlands. We used a 7-year grazing experiment with horse and cattle grazing at two densities namely 0.5 and 1 animal ha(-1) (equivalent to 0.4 and 0.8 LSU), including a rotation regime i.e. 1 year summer grazing with 1 cattle ha(-1) followed by 1 ungrazed year. We recorded vole activity signs as a measure for presence (i.e. presence of burrow entrances, droppings, runways and plant clippings) in circular 2 m(2) plots along transects. Low grazer densities, regardless of species, corresponded to higher vole presence. Vole presence tended to be greater with cattle grazing than with horse grazing, but the difference was not significant. The increase in vole presence was greater in the rotation regime than with low or high density cattle grazing. The different vole activity signs provided similar results to each other with the exception of burrow entrances, suggesting that this measure is less accurate in predicting vole presence. Hence, voles clearly responded to the different grazing regimes. Our results have high relevance for conservation, in particular in systems where small mammals contribute to important ecological processes (e.g. bioturbation, seed dispersal) and play a crucial role in the survival of (iconic) higher trophic level taxa such as raptors or mammalian predators. In such systems, conservation management may best implement low-density cattle or rotation grazing. (C) 2018 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved

Rotation grazing as a conservation management tool:Vegetation changes after six years of application in a salt marsh ecosystem

Grazing is commonly used in conservation to promote biodiversity, but the search for a grazing management regime that optimises biodiversity is still ongoing. Rotation grazing, where grazing is followed by a relatively long period of non-grazing, is a relative new tool in conservation management, and empirical studies on its effects on biodiversity are scarce. In this study, we tested for the effects of this rotation grazing on vegetation in comparison with more traditional regimes. We used a grazing experiment on the salt marsh of Noord-Friesland Buitendijks, The Netherlands, where we determined the effect of three rotation cycles (6 years; one year summer grazing with 1 cattle ha(-1) alternated with an ungrazed year) on species richness, temporal turnover and composition in comparison with more traditional regimes of summer grazing with horses and cattle at two densities (0.5 and 1 animal ha(-1)): We also determined the change in cover of two species of specific concern, Aster tripolium (an important host plant for pollinators) and Elytrigia atherica (an invasive dominant species). After six years, species richness increased in all grazing regimes, but less in rotation than in grazing with 1 horse or 1 cattle ha(-1). Species turnover was similar across all grazing regimes. Species composition in rotation differed from compositions in 1 cattle and 1 horse ha(-1). The increase in cover of A. tripolium was lower under rotation than grazing with 0.5 cattle ha(-1), but not different to the other regimes. Change in cover of E. atherica did not significantly differ across regimes, and showed a trend of increase in the ungrazed regime only. Hence, we found that the effects of rotation grazing on vegetation are relatively similar to the grazing regimes with cattle or horses in low densities. The implementation of this rotation regime over the more traditional regimes remains to be decided by the conservation body, depending on its applicability in terms of available grazing areas and livestock, as well as overall conservation goals

Seven different genes encode a diverse mixture of isoforms of Bet v 1, the major birch pollen allergen

BACKGROUND: Pollen of the European white birch (Betula pendula, syn. B. verrucosa) is an important cause of hay fever. The main allergen is Bet v 1, member of the pathogenesis-related class 10 (PR-10) multigene family. To establish the number of PR-10/Bet v 1 genes and the isoform diversity within a single tree, PCR amplification, cloning and sequencing of PR-10 genes was performed on two diploid B. pendula cultivars and one interspecific tetraploid Betula hybrid. Sequences were attributed to putative genes based on sequence identity and intron length. Information on transcription was derived by comparison with homologous cDNA sequences available in GenBank/EMBL/DDJB. PCR-cloning of multigene families is accompanied by a high risk for the occurrence of PCR recombination artifacts. We screened for and excluded these artifacts, and also detected putative artifact sequences among database sequences. RESULTS: Forty-four different PR-10 sequences were recovered from B. pendula and assigned to thirteen putative genes. Sequence homology suggests that three genes were transcribed in somatic tissue and seven genes in pollen. The transcription of three other genes remains unknown. In total, fourteen different Bet v 1-type isoforms were identified in the three cultivars, of which nine isoforms were entirely new. Isoforms with high and low IgE-reactivity are encoded by different genes and one birch pollen grain has the genetic background to produce a mixture of isoforms with varying IgE-reactivity. Allergen diversity is even higher in the interspecific tetraploid hybrid, consistent with the presence of two genomes. CONCLUSION: Isoforms of the major birch allergen Bet v 1 are encoded by multiple genes, and we propose to name them accordingly. The present characterization of the Bet v 1 genes provides a framework for the screening of specific Bet v 1 genes among other B. pendula cultivars or Betula species, and for future breeding for trees with a reduced allergenicity. Investigations towards sensitization and immunotherapy should anticipate that patients are exposed to a mixture of Bet v 1 isoforms of different IgE-reactivity, even if pollen originates from a single birch tree

A European reference collection of rose varieties : final report

An integrated pilot database was constructed containing administrative, morphological and molecular data as well as pictures of each variety. In spite of some encountered difficulties, it was demonstrated that two laboratories can produce substantially equivalent data and that the molecular data produced is useful as a tool for managing reference collections, prescreening and quality assuranc

Microsatellite analysis of Damask rose (Rosa damascena Mill.) accessions from various regions in Iran reveals multiple genotypes

BACKGROUND: Damask roses (Rosa damascena Mill.) are mainly used for essential oil production. Previous studies have indicated that all production material in Bulgaria and Turkey consists of only one genotype. Nine polymorphic microsatellite markers were used to analyze the genetic diversity of 40 accessions of R. damascena collected across major and minor rose oil production areas in Iran. RESULTS: All microsatellite markers showed a high level of polymorphism (5–15 alleles per microsatellite marker, with an average of 9.11 alleles per locus). Cluster analysis of genetic similarities revealed that these microsatellites identified a total of nine different genotypes. The genotype from Isfahan province, which is the major production area, was by far the most common genotype (27/40 accessions). It was identical to the Bulgarian genotype. Other genotypes (each represented by 1–4 accessions) were collected from minor production areas in several provinces, notably in the mountainous Northwest of Iran. CONCLUSION: This is the first study that uncovered genetic diversity within Damask rose. Our results will guide new collection activities to establish larger collections and manage the Iranian Damask rose genetic resources. The genotypes identified here may be directly useful for breeding