Characterization of genetic variation within table grape varieties (Vitis vinifera L.) based on AFLP markers

AFLPs were used to characterize a collection of 35 table grape varieties. A single AFLP reaction with a single combination of selective primers yielded an average of 50 polymorphic and scorable amplified bands in this collection and was enough to unequivocally identify each analyzed variety, Genetic similarity between different varieties was estimated, based on the results obtained with two primer combinations, to be between 0.65 and 0.90, while sibling varieties derived from the same cross showed a genetic similarity higher than 0.80, The analysis of several samples belonging to the same varieties, yet from different origins, showed stability of the AFLP patterns as to unequivocally and reproducibly identify them. Furthermore, some specific primer combinations detected a low level of variation that could be due to somatic variation and would be useful in clonal identification

Intestinal anti-inflammatory effects of RGD-functionalized silk fibroin nanoparticles in trinitrobenzenesulfonic acid-induced experimental colitis in rats

Background: Current treatment of inflammatory bowel disease is based on the use of immunosuppressants or anti-inflammatory drugs, which are characterized by important side effects that can limit their use. Previous research has been performed by administering these drugs as nanoparticles that target the ulcerated intestinal regions and increase their bioavailability. It has been reported that silk fibroin can act as a drug carrier and shows anti-inflammatory properties. Purpose: This study was designed to enhance the interaction of the silk fibroin nanoparticles (SFNs) with the injured intestinal tissue by functionalizing them with the peptide motif RGD (arginine–glycine–aspartic acid) and to evaluate the intestinal anti-inflammatory properties of these RGD-functionalized silk fibroin nanoparticles (RGD-SFNs) in the trinitrobenzenesulfonic acid (TNBS) model of rat colitis. Materials and methods: SFNs were prepared by nanoprecipitation in methanol, and the linear RGD peptide was linked to SFNs using glutaraldehyde as the crosslinker. The SFNs (1 mg/rat) and RGD-SFNs (1 mg/rat) were administered intrarectally to TNBS-induced colitic rats for 7 days. Results: The SFN treatments ameliorated the colonic damage, reduced neutrophil infiltration, and improved the compromised oxidative status of the colon. However, only the rats treated with RGD-SFNs showed a significant reduction in the expression of different pro-inflammatory cytokines (interleukin IL]-1ß, IL-6, and IL-12) and inducible nitric oxide synthase in comparison with the TNBS control group. Moreover, the expression of both cytokine-induced neutrophil chemoattractant-1 and monocyte chemotactic protein-1 was significantly diminished by the RGD-SFN treatment. However, both treatments improved the intestinal wall integrity by increasing the gene expression of some of its markers (trefoil factor-3 and mucins). Conclusion: SFNs displayed intestinal anti-inflammatory properties in the TNBS model of colitis in rats, which were improved by functionalization with the RGD peptide

Plant-symbiotic fungi as chemical engineers: multi-genome analysis of the Clavicipitaceae reveals dynamics of alkaloid Loci

The fungal family Clavicipitaceae includes plant symbionts and parasites that produce several psychoactive and bioprotective alkaloids. The family includes grass symbionts in the epichloae clade (Epichloë and Neotyphodium species), which are extraordinarily diverse both in their host interactions and in their alkaloid profiles. Epichloae produce alkaloids of four distinct classes, all of which deter insects, and some—including the infamous ergot alkaloids—have potent effects on mammals. The exceptional chemotypic diversity of the epichloae may relate to their broad range of host interactions, whereby some are pathogenic and contagious, others are mutualistic and vertically transmitted (seed-borne), and still others vary in pathogenic or mutualistic behavior. We profiled the alkaloids and sequenced the genomes of 10 epichloae, three ergot fungi (Claviceps species), a morning-glory symbiont (Periglandula ipomoeae), and a bamboo pathogen (Aciculosporium take), and compared the gene clusters for four classes of alkaloids. Results indicated a strong tendency for alkaloid loci to have conserved cores that specify the skeleton structures and peripheral genes that determine chemical variations that are known to affect their pharmacological specificities. Generally, gene locations in cluster peripheries positioned them near to transposon-derived, AT-rich repeat blocks, which were probably involved in gene losses, duplications, and neofunctionalizations. The alkaloid loci in the epichloae had unusual structures riddled with large, complex, and dynamic repeat blocks. This feature was not reflective of overall differences in repeat contents in the genomes, nor was it characteristic of most other specialized metabolism loci. The organization and dynamics of alkaloid loci and abundant repeat blocks in the epichloae suggested that these fungi are under selection for alkaloid diversification. We suggest that such selection is related to the variable life histories of the epichloae, their protective roles as symbionts, and their associations with the highly speciose and ecologically diverse cool-season grasses

Variabilidad genética entre cultivares de albaricoquero tradicionales (Prunus armeniaca L.) del sureste español

The fast rotation of new cultivars demanded by modern fruit growers implies the loss of many old varieties with valuable characters. Then, the need arises to keep and characterize this germplasm for future breeding projects. The region of Murcia, together with Valencia, in the East and Southeast of Spain respectively, are important and ancient producers of apricot (Prunus armeniaca L.), and many local cultivars have appeared and diversified in this area. A collection of 28 of these old cultivars, plus eight clonal selections of the cultivar "Búlida", is maintained at the Instituto Murciano de Investigación y Desarrollo Agrario y Alimentario (IMIDA, Murcia, Spain). In order to characterize their genetic diversity and to identify the collection with molecular markers, 17 microsatellite primers pairs were used. Thirteen of these primers produced polymorphic repeatable amplification patterns, and 31 genotypes were identified among the 36 apricot accessions. In addition to this, an evaluation of the genetic diversity found in the field within the cultivar "Búlida" was made, the predominant cultivar for the canning industry in the region. For this, 66 field samples were analyzed with seven microsatellite markers. The results suggest that all the samples could derive from four closely-related genotypes, one of them accounting for 89% of the samples.La rápida rotación de nuevas variedades que exige la fruticultura moderna, implica la pérdida de muchas variedades antiguas con caracteres potencialmente valiosos. En consecuencia, surge la necesidad de mantener y caracterizar este germoplasma para futuros proyectos de mejora. La región de Murcia, junto con la de Valencia, en el este y sureste de España respectivamente, son importantes y antiguas productoras de albaricoque (Prunus armeniaca L.), y muchos cultivares autóctonos han aparecido y se han diversificado en la zona. En el Instituto Murciano de Investigación y Desarrollo Agrario y Alimentario (IMIDA, Murcia, España) se mantiene una colección de 28 de estas antiguas variedades más 8 selecciones clonales del cv. "Búlida". Para caracterizar molecularmente la diversidad e identidad genética de esta colección, se emplearon 17 marcadores microsatélite. En 13 de ellos se detectaron pautas de amplificación polimórficas y reproducibles, y se pudieron identificar 31 genotipos. Además de la evaluación de la colección, se planteó la evaluación de la diversidad genética en campo del cv. "Búlida", que es la predominante para uso en la industria conservera de la región. Para ello se analizaron 66 muestras de campo con 7 marcadores microsatélite. Los resultados sugieren que todas las muestras de campo podrían derivar de cuatro genotipos estrechamente relacionados, agrupando uno de ellos al 89% de las muestras

Relaciones genéticas entre siete formas especializadas de Fusarium oxysporum Sch.:Fr. Determinadas mediante la secuenciación de la región ITS y AFLPs

The fungus Fusarium oxysporum Sch.:Fr. presents a high biological and genetic variability, manifested by the existenceof many specialized forms and races. With the goal of evaluating the genetic relationship among different specializedforms, an experiment was carried out involving the application of two types of molecular markers. One consistedof sequencing the internal transcribed spacer (ITS) region of the ribosomal DNA of 17 isolates belonging toseven forms: F.o. melonis (4 isolates), F.o. dianthi (2), F.o. niveum (4), F.o. lycopersici (2), F.o. radicis-lycopersici (3),F.o. lagenaria (1) and F.o. luffae (1). Analysis of these sequences revealed that isolates from different forms presentan identical sequence while isolates of the same form appear distributed in different groups of the dendrogram. Thisobservation was confirmed by an AFLP analysis. In addition to the previously cited forms, ten more were studied inthis experiment, belonging to F.o. ciceris, F.o. cucumerinum, F. proliferatum and F.o. asparagi, as well as two non-pathogenicisolates. The dendrogram calculated with the AFLP markers did not reveal any genetic structuration of the10 specialized forms. These data, in line with those obtained by other authors, seem to suggest that in general, the specializedforms of F. oxysporum do not constitute monophyletic lineages because they evolve in a divergent way. It ratherseems that widely different genotypes could share similar genetic factors conferring pathogenic specificity.El hongo Fusarium oxysporum Sch.:Fr. presenta una elevada variabilidad biológica y genética que se manifiesta por la existencia de numerosas formas especializadas y razas. Con el fin de evaluar la relación genética entre diferentes formas especializadas se aplicaron dos tipos de marcadores genéticos. En primer lugar se secuenció la región ITS (internal transcribed spacer) del ADN ribosomal de 17 aislados pertenecientes a siete de dichas formas: F.o. melonis (4 aislados), F.o. dianthi (2), F.o. niveum (4), F.o. lycopersici (2), F.o. radicis-lycopersici (3), F.o. lagenaria (1) y F.o. luffae (1). El análisis de estas secuencias reveló que aislados de diferentes formas presentan una secuencia idéntica, mientras que aislados de la misma forma aparecen en grupos diferentes del correspondiente dendrograma. Esta observación se confirmó mediante marcadores AFLP de las mismas formas especializadas y 10 más pertenecientes a F.o. ciceris, F.o. cucumerinum, F. proliferatum y F.o. asparagi, (...

Biotype determination of Spanish populations of Bemisia tabaci (Hemiptera Aleyrodidae)

A survey was made to assess the biotype status of populations of the white fly Bemisia tabaci (Gennadius) in Spain. The study involved observation of the squash silverleaf reaction, analysis of esterase patterns and application of a RAPD-PCR technique. The results obtained by the three methods were fully consistent and showed that the Spanish populations of B. tabaci were composed of two genetic types. One corresponded to populations of the B biotype, found in Tenerife (Canary Islands), Barcelona, Madrid, Malaga and Almeria. The other, showing a unique RAPD and esterase pattern, was found in Majorca (Balearic Islands), Seville, Valencia, Murcia and Almeria, as well as in the Algarve Region of Portugal. RAPD patterns of other populations from the rest of the world used for comparison showed that populations from Arizona (USA), Israel, France, Denmark, Italy, Netherlands and Japan have similar RAPD patterns typical of the B biotype. By contrast, populations from the Iberian Peninsula, Turkey, India, Pakistan and Arizona (A biotype), showed different and unique patterns