Factors involved in Agrobacterium tumefaciens-mediated gene transfer into Pinus nigra Arn. ssp. salzmannii (Dunal) Franco

Cotyledons from dissected sterile embryos of salgareño pine (Pinus nigra Arn. ssp. salzmannii (Dunal) Franco) were inoculated with different disarmed Agrobacterium tumefaciens strains harbouring the binary vector p35SGUSint. The transient expression of a β-glucuronidase gene (uidA) was studied, using a histochemical staining procedure. Nineteen days after inoculation, the activity of β-glucuronidase was detected in epidermal and subepidermal layers of cotyledonary explants. The EHA105 strain harbouring a disarmed agropine-type Ti-plasmid (pTiBO542) was the most effective for gene transfer of the uidA gene. The effects of exudates and extracts from 0-day-old embryos on induction of vir gene expression in A. tumefaciens were also examined. The results of this study showed that salgarño pine embryo exudates contain a substance(s) that induce vir gene expression, in similar way to that observed with 100 μM acetosyringone (AS).All these findings suggest that T-DNA processing and transfer might take place when Agrobacterium infects suitable tissues of salgareño pine.     

Utilization of genetic resources for the introduction and adaptation of exotic vegetable crops: The case of pepino (Solanum muricatum)

Summary Pepino (Solanum muricatum), a vegetatively propagated plant from the Andean region used for its edible fruits, has been identified as a potential crop for greenhouse cultivation in Mediterranean regions. However, attempts for introducing it have been unsuccessful, either because of the low yield, poor fruit quality, or both. Screening of germplasm under Mediterranean conditions showed that sources of variation for high yield existed in the cultivated genepool and that wild species S. caripense and S. tabanoense could contribute to a considerable improvement of soluble solids content (SSC) of pepino. Progenies obtained after crossing genetically distant (AFLP-based) parental clones were heterotic for yield, and allowed the selection of clones with an improved combination of yield and SSC. As a result of this intraspecific programme, two new improved cultivars (‘Turia’ and ‘Valencia’), which outperform the rest of cultivars available, have been selected for cultivation in Mediterranean conditions. The interspecific programme involved the selection of clones with high yield and SSC in backcross generations. The results show that introgression of genes from the wild species can contribute to improve the SSC of pepino. The backcross programme is in an advanced stage and new cultivars derived from the interspecific crosses are expected to be released in a near future. New prospects for the future in pepino breeding include the genetic transformation, the establishment of a genetic map, and the use of the genomic information from related Solanaceae important crops. All the information obtained is illustrative for the breeding for adaptation of vegetatively propagated crops.     

Effect of Fucoidan on the Mitochondrial Membrane Potential (ΔΨm) of Leukocytes from Patients with Active COVID-19 and Subjects That Recovered from SARS-CoV-2 Infection

Fucoidan is a polysaccharide obtained from marine brown algae, with anti-inflammatory, anti-viral, and immune-enhancing properties, thus, fucoidan may be used as an alternative treatment (complementary to prescribed medical therapy) for COVID-19 recovery. This work aimed to determine the ex-vivo effects of treatment with fucoidan (20 µg/mL) on mitochondrial membrane potential (ΔΨm, using a cationic cyanine dye, 3,3′-dihexyloxacarbocyanine iodide (DiOC₆(3)) on human peripheral blood mononuclear cells (HPBMC) isolated from healthy control (HC) subjects, COVID-19 patients (C-19), and subjects that recently recovered from COVID-19 (R1, 40 ± 13 days after infection). In addition, ex-vivo treatment with fucoidan (20 and 50 µg/mL) was evaluated on ΔΨm loss induced by carbonyl cyanide 3-chlorophenylhydrazone (CCCP, 150 µM) in HPBMC isolated from healthy subjects (H) and recovered subjects at 11 months post-COVID-19 (R2, 335 ± 20 days after infection). Data indicate that SARS-CoV-2 infection induces HPBMC loss of ΔΨm, even 11 months after infection, however, fucoidan promotes recovery of ΔΨm in PBMCs from COVID-19 recovered subjects. Therefore, fucoidan may be a potential treatment to diminish long-term sequelae from COVID-19, using mitochondria as a therapeutic target for the recovery of cellular homeostasis.     

Mating Disruption of Striped Rice Stem Borer: Importance of Early Deployment of Dispensers and Impact on Airborne Pheromone Concentration

正Mating disruption(MD) is an effective environmentallyfriendly control method against the striped rice stem borer(RSB), Chilo suppressalis(Lepidoptera: Crambidae). In this study, the current MD dispensers release the pheromone exponentially, with higher initial release rates that decrease throughout the time. To adjust the timing of dispensers' deployment and evaluate the importance of controlling the early first or the second male flight,     

Accuracy of pairwise methods in the reconstruction of family relationships, using molecular information from turbot (Scophthalmus maximus)

Many estimators and algorithms have been developed to infer the genealogical relationships from molecular marker data when there is no pedigree information. Most pairwise methods provide estimates in a continuous range that needs to be converted into genealogical relationships (namely full-sibs, half-sibs and unrelated) if there is a previous knowledge of the population structure. Transformations are usually based on arbitrary thresholds, but the possibility of correcting the coancestry estimates via explicit pedigree reconstruction methods has been suggested. Using molecular data for ten highly polymorphic microsatellite loci on a population of turbot (Scophthalmus maximus) with a known genealogy, the behaviour of four pairwise marker-based coancestry estimators and the molecular coancestry has been evaluated. The population consisted on 138 families with 4 full-sib individuals each and one family with 8 full-sib individuals (up to 15 half-sib families were also present due to the sharing of parents between some of the full-sibs families). Our results suggested that transforming the pairwise estimators and the molecular coancestry to family relationships through the establishment of thresholds performs slightly better than the explicit pedigree reconstruction method, when accuracy is measured in a pairwise basis. However, if joint relationships between more than two individuals were tested at a time, the threshold methods led to a high percentage of incongruous triads of full-sib individuals, with Mendelian incompatibilities appearing in congruous full-sib families (more than 70% and 60% in our study, respectively). The explicit pedigree reconstruction approach, due to its nature, is free from such problems. Therefore, the pedigree reconstruction approach seems to be a valuable tool to provide a congruent and compatible pedigree when the pairwise marker-based coancestry matrices or the molecular coancestry need to be transformed.     

Susceptibility of the Mexican bean beetle <Emphasis Type="Italic">Epilachna varivestis</Emphasis> Mulsant (Coleoptera: Coccinellidae) to endemic isolates of <Emphasis Type="Italic">Beauveria bassiana</Emphasis> (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae)

Entomopathogenic fungi represent excellent candidates for biological insecticides. Among the many entomopathogenic fungi, Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) is one of the most promising species. Here, we report the results of infection studies performed using four B. bassiana native isolates (Bb37, Bb38, Bb40, and Bb45) compared with the commercial product Mycotrol^® (strain GHA) on adult Mexican bean beetle Epilachna varivestis Mulsant (Coleoptera: Coccinellidae), one of the most important pests of bean production in Mexico. First, single concentration (1 × 10⁸ conidia mL^?1) assays were carried out using all isolates applied using an immersion method. Examinations at 10 days after inoculation indicated that isolates Bb37, Bb38, and Bb40 significantly reduced adult survival, causing 60–75% mortality compared to the commercial strain GHA (33%) and control (29%). Second, using two selected isolates (Bb37 and Bb40), the mean lethal concentration values (LC₅₀) were estimated for third instar larvae and adult E. varivestis. The LC₅₀ values for Bb37 and Bb40 isolates decreased 5.26-fold and 3.19-fold, respectively, in third instars compared with adults. However, such difference for Bb40 isolate was not significant. Finally, an experiment, to compare the median survival time (MST) values between third instar and adult E. varivestis, was conducted using Bb37 and Bb40 at 1 × 10⁹ conidia mL^?1. MST values were significantly reduced against larvae (87 and 100 h) compared with adults (130 and 134 h) by Bb37 and Bb40, respectively. We conclude that native isolates of B. bassiana represent an important alternative for the control of E. varivestis. However, to demonstrate its effectiveness under field conditions, detailed studies are needed.     

The politics of water democracy: insights from grassroot struggles in the Ecuadorian Highlands

In the past two decades spaces for user participation have been opened within water governance structures at many scales. In this contribution, based on a case study of the Provincial Water Users Federation Interjuntas‐Chimborazo in the Ecuadorian Highlands, I explore how and why formal participation of water users in itself is problematic in terms of democracy. The case shows that for organised peasant water users to work on more democratic water governance, the creation of upscaled federations, alliances, networks and sometimes street protests is crucial to open up spaces in which their interests are represented. This suggests that democracy is not merely about participation, but more importantly, it is about the politics of how democracy is made through conflicts, protests, negotiations and the creation of strategic alliances that challenge the structures and processes through which decisions are taken.     

Thinning enhances stool resistance to an extreme drought in a Mediterranean Quercus ilex L. coppice: insights for adaptation

New Forests - Mediterranean holm oak forests are subjected to chronic seasonal droughts coinciding with the warmest conditions during the summer. Importantly, climate change projections support...