Verticillium Wilt Evaluation of Olive Breeding Selections Under Semi-Controlled Conditions

Genetic resistance is the most recommended measure to control verticillium wilt in olive (VWO), a vascular disease caused by the soil-borne fungus Verticillium dahliae, which has promoted the development of olive breeding programs aimed at obtaining new resistant and highly yielding cultivars in recent years. Screening has been commonly performed under controlled conditions in grow chamber after artificial inoculation during the early stage of breeding programs, but additional evaluation is necessary to confirm previous results as well as to test for additional agronomic traits. During this study, 20 breeding selections initially classified as resistant to the disease have been re-evaluated in artificially infested soils under natural environmental conditions. The maximum disease incidence (52.6%) was reached at 26 months after planting, and the disease intensity index reached the maximum value of 38.5% at 29 months after planting. Nine breeding selections consistently confirmed the previous results regarding resistance to V. dahliae infection; however, contradictory results, compared with those of previous evaluations under controlled conditions in grow chambers, were obtained for the rest of selections tested, thereby underlining the need for long-term experimentation under natural environmental conditions. Additional positive agronomic traits, such as early bearing, were also observed for some of the resistant selections, but plant vigor varied. Some seem highly promising for release as new cultivars when characterization of other important agronomic traits is completed in the future.

Apps para el aprendizaje de las matemáticas en educación infantil

Las Tecnologías del Aprendizaje y el Conocimiento (TAC) tienen una influencia cada vez mayor en la manera de mediar el aprendizaje de los más jóvenes. El incremento del proceso de enseñanza y aprendizaje mediado por las TAC en el ámbito de la educación y en el ámbito doméstico, induce a la creación de nuevas herramientas efectivas, avaladas por la ciencia y diseñadas para mejorar el aprendizaje de nuestros alumnos. El desafío al que se enfrenta la psicología de la educación consiste en fomentar éstas tecnologías y ponerlas al servicio de la comunidad educativa y sin perder de vista el hecho de generar productos atractivos para los usuarios y que puedan generar rendimiento comercial para las empresas. Pretendiendo generar además de una transferencia efectiva de la labor científica, el aumento en la visibilidad de la investigación. En este trabajo, presentamos 9 aplicaciones (APPs) diseñadas para Tablet y Smartphone, adaptadas a los diferentes sistemas operativos actuales, destinadas a trabajar sobre las bases cognitivas asociadas con el aprendizaje de la matemática temprana. Con el objeto de crear una herramienta atractiva para el alumnado de 4 a 7 años, se ha contado con la colaboración de la empresa de entretenimiento y divulgación infantil Babyradio, colaborando en el desarrollo gráfico y en la transferencia de los resultados de la inves tigación. Una vez demostrada la validez empírica de estas APPs, los maestros, el sistema educativo y las empresas de software dispondrían de un material de apoyo didáctico contrastado. El objetivo principal del trabajo es contribuir en el desarrollo de las habilidades matemáticas de los niños de 4 a 7 años para que estos puedan afrontar con éxito los requerimientos de la escuela y para que puedan resolver situaciones en sus vidas diarias, promoviendo por otro lado, el cambio actitudinal del alumnado con respecto a las matemáticas

First RNA-seq approach to study fruit set and parthenocarpy in zucchini (Cucurbita pepo L.)

BACKGROUND

Zucchini fruit set can be limited due to unfavourable environmental conditions in off-seasons crops that caused ineffective pollination/fertilization. Parthenocarpy, the natural or artificial fruit development without fertilization, has been recognized as an important trait to avoid this problem, and is related to auxin signalling. Nevertheless, differences found in transcriptome analysis during early fruit development of zucchini suggest that other complementary pathways could regulate fruit formation in parthenocarpic cultivars of this species. The development of next-generation sequencing technologies (NGS) as RNA-sequencing (RNA-seq) opens a new horizon for mapping and quantifying transcriptome to understand the molecular basis of pathways that could regulate parthenocarpy in this species. The aim of the current study was to analyze fruit transcriptome of two cultivars of zucchini, a non-parthenocarpic cultivar and a parthenocarpic cultivar, in an attempt to identify key genes involved in parthenocarpy.

RESULTS

RNA-seq analysis of six libraries (unpollinated, pollinated and auxin treated fruit in a non-parthenocarpic and parthenocarpic cultivar) was performed mapping to a new version of C. pepo transcriptome, with a mean of 92% success rate of mapping. In the non-parthenocarpic cultivar, 6479 and 2186 genes were differentially expressed (DEGs) in pollinated fruit and auxin treated fruit, respectively. In the parthenocarpic cultivar, 10,497 in pollinated fruit and 5718 in auxin treated fruit. A comparison between transcriptome of the unpollinated fruit for each cultivar has been performed determining that 6120 genes were differentially expressed. Annotation analysis of these DEGs revealed that cell cycle, regulation of transcription, carbohydrate metabolism and coordination between auxin, ethylene and gibberellin were enriched biological processes during pollinated and parthenocarpic fruit set.

CONCLUSION

This analysis revealed the important role of hormones during fruit set, establishing the activating role of auxins and gibberellins against the inhibitory role of ethylene and different candidate genes that could be useful as markers for parthenocarpic selection in the current breeding programs of zucchini.

Genome-scale examination of NBS-encoding genes in blueberry

Blueberry is an important crop worldwide. It is, however, susceptible to a variety of diseases, which can lead to losses in yield and fruit quality. Although screening studies have identified resistant germplasm for some important diseases, still little is known about the molecular basis underlying that resistance. The most predominant type of resistance (R) genes contains nucleotide binding site and leucine rich repeat (NBS-LRR) domains. The identification and characterization of such a gene family in blueberry would enhance the foundation of knowledge needed for its genetic improvement. In this study, we searched for and found a total of 106 NBS-encoding genes (including 97 NBS-LRR) in the current blueberry genome. The NBS genes were grouped into eleven distinct classes based on their domain architecture. More than 22% of the NBS genes are present in clusters. Ten genes were mapped onto seven linkage groups. Phylogenetic analysis grouped these genes into two major clusters based on their structural variation, the first cluster having toll and interleukin-1 like receptor (TIR) domains and most of the second cluster containing a coiled-coil domain. Our study provides new insight into the NBS gene family in blueberry and is an important resource for the identification of functional R-genes.

Expression Profile of Carotenoid Cleavage Dioxygenase Genes in Summer Squash (Cucurbita pepo L.)

Carotenoids are important dietary components that can be found in vegetable crops. The accumulation of these compounds in fruit and vegetables is altered by the activity of carotenoid cleavage dioxygenases (CCDs) enzymes that produce their degradation. The aim of this work was to study the possible implication of CCD genes in preventing carotenoid storage in the horticultural crop summer squash (Cucurbita pepo L.). The relationship between the presence of these compounds and gene expression for CCDs was studied in three varieties showing different peel and flesh colour. Expression analysis for the CCD genes CpNCED1, CpNCED2, CpNCED3, CpNCED9, CpCCD1, CpCCD4a, CpCCD4b and CpCCD8 was carried out on different organs and at several fruit developmental stages. The results showed that the CpCCD4a and CpCCD4b genes were highly expressed in the variety with lowest carotenoid content suggesting a putative role in carotenoid accumulation pattern in summer squash fruit.

Carotenogenic gene expression and carotenoid accumulation in three varieties of Cucurbita pepo during fruit development

The control of gene expression is a crucial regulatory mechanism in carotenoid accumulation of fruits and flowers. We investigated the role of transcriptional regulation of nine genes involved in the carotenoid biosynthesis pathway in three varieties of Cucurbita pepo with evident differences in fruit color. The transcriptional levels of the key genes involved in the carotenoid biosynthesis were higher in flower-, leaf-, and fruit skin tissues than flesh tissues. This correlated with higher concentration of carotenoid content in these tissues. The differential expression among the colored and white cultivars detected for some genes, such as LCYe, in combination with other regulatory mechanisms, could explain the large differences found in terms of carotenoid content among the three varieties. These results are a first step to elucidate carotenogenesis in C. pepo and demonstrate that, in general, regulation of the pathway genes is a critical factor that determines the accumulation of these compounds.

In-house validation of a multiplex real-time PCR method for simultaneous detection of Salmonella spp., Escherichia coli O157 and Listeria monocytogenes

A wide variety of qPCR methods currently exist for Salmonella spp., Escherichia coli O157 and Listeria monocytogenes detection. These methods target several genes and use different detection chemistries, either in simplex or in multiplex formats. However, the majority of these methods have not been carefully validated, and the number of validated methods that use multiplex qPCR is even lower. The aim of the present study was to develop and validate a multiplex qPCR method from previously validated simplex qPCR primers and probes. A modified broth medium was selected and primary and secondary enrichment times were further optimized. Efficiency of the newly combined qPCR system was comprised between 91% and 108%, for simplex and multiplex analyses. A total of 152 food and environmental, natural and spiked samples, were analyzed for the evaluation of the method obtaining values above 91% that were reached for all the quality parameters analyzed. A very low limit of detection (5 cfu/25 g after enrichment) for simultaneous identification of these 3 pathogens was obtained.

Evaluation of different pulverisation methods for RNA extraction in squash fruit: lyophilisation, cryogenic mill and mortar grinding

INTRODUCTION

Quality and integrity of RNA are critical for transcription studies in plant molecular biology. In squash fruit and other high water content crops, the grinding of tissue with mortar and pestle in liquid nitrogen fails to produce a homogeneous and fine powered sample desirable to ensure a good penetration of the extraction reagent.

OBJECTIVE

To develop an improved pulverisation method to facilitate the homogenisation process of squash fruit tissue prior to RNA extraction without reducing quality and yield of the extracted RNA.

METHODOLOGY

Three methods of pulverisation, each followed by the same extraction protocol, were compared. The first approach consisted of the lyophilisation of the sample in order to remove the excess of water before grinding, the second one used a cryogenic mill and the control one a mortar grinding of frozen tissue. The quality of the isolated RNA was tested by carrying out a quantitative real time downstream amplification.

RESULTS

In the three situations considered, mean values for A(260) /A(280) indicated minimal interference by proteins and RNA quality indicator (RQI) values were considered appropriate for quantitative real-time polymerase chain reaction (qRT-PCR) amplification. Successful qRT-PCR amplifications were obtained with cDNA isolated with the three protocols.

CONCLUSION

Both apparatus can improve and facilitate the grinding step in the RNA extraction process in zucchini, resulting in isolated RNA of high quality and integrity as revealed by qRT-PCR downstream application. This is apparently the first time that a cryogenic mill has been used to prepare fruit samples for RNA extraction, thereby improving the sampling strategy because the fine powder obtained represents a homogeneous mix of the organ tissue.

RNA quality assessment: a view from plant qPCR studies

Reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) is probably the most common molecular technique used in transcriptome analyses today. The simplicity of the technology and associated protocols that generate results without the need to understand the underlying principles has made RT-qPCR the method of choice for RNA quantification. Rather than the 'gold standard technology' often used to describe it, the performance of RT-qPCR suffers from considerable pitfalls during general workflow. The inconsistency of conventional methods for the evaluation of RNA quality and its influence on qPCR performance as well as stability of reference genes is summarized and discussed here.

Selection of reference genes for gene expression studies in zucchini (Cucurbita pepo) using qPCR

The zucchini (Cucurbita pepo) is an important food crop, the transcriptomics of which are a fundamental tool to accelerate the development of new varieties by breeders. However, the suitability of reference genes for data normalization in zucchini has not yet been studied. The aim of this study was to assess the suitability of 13 genes for their potential use as reference genes in quantitative real-time PCR. Assays were performed on 34 cDNA samples representing plants under different stresses and at different developmental stages. The application of geNorm and NormFinder software revealed that the use of a combination of UFP, EF-1A, RPL36aA, PP2A, and CAC genes for the different experimental sets was the best strategy for reliable normalization. In contrast, 18S rRNA and TUA were less stable and unsuitable for use as internal controls. These results provide the possibility to allow more accurate use of qPCR in this horticultural crop.

Evaluation of candidate reference genes for expression studies in Pisum sativum under different experimental conditions

Reverse transcription quantitative real-time polymerase chain reaction is the most accurate measure of gene expression in biological systems. The data are analyzed through a process called normalization. Internal standards are essential for determining the relative gene expression in different samples. For this purpose, reference genes are selected based on their constitutive expression across samples. At present, there has not yet been any reference gene identified in any organism that is universally optimal across different tissue types or disease situations. Our goal was to test the regulation of 11 potential references for pea. These included eight commonly used and three new candidates. Twenty-six samples, including different tissues, treatments and genotypes, were addressed in this analysis. For reliable data normalization, the most suitable combination of reference genes in each experimental set was constructed with at least two out the five more stably expressed references in the whole experimental series (i.e. protein phosphatase 2A, beta-tubulin, GH720838, actin and GH720808). To validate the determined measure of gene-stability, the gene-specific variation was calculated using different normalization factors. The most non-specific variation was removed when the most stable genes were used, highlighting the importance of the adequate choice of internal controls in gene expression experiments. The set of reference genes presented here will provide useful guidelines as starting point for reference gene selection in pea studies under conditions other than those tested here.

Validation of QTLs for Orobanche crenata resistance in faba bean (Vicia faba L.) across environments and generations

Broomrape (Orobanche crenata Forsk.) is a major root-parasite of faba bean (Vicia faba L.), that seriously limits crop cultivation in the whole Mediterranean area. This parasitic weed is difficult to control, difficult to evaluate and the resistance identified so far is of polygenic nature. This study was conducted to identify genetic regions associated with broomrape resistance in recombinant inbred lines (RILs) and to validate their previous location in the original F(2) population derived from the cross between lines Vf6 and Vf136. A progeny consisting of 165 F(6) RILs was evaluated in three environments across two locations in 2003 and 2004. Two hundred seventy seven molecular markers were assigned to 21 linkage groups (9 of them assigned to specific chromosomes) that covered 2,856.7 cM of the V. faba genome. The composite interval mapping on the F(6) map detected more quantitative trait loci (QTL) than in the F(2) analysis. In this sense, four QTLs controlling O. crenata resistance (Oc2-Oc5) were identified in the RI segregant population in three different environments. Only Oc1, previously reported in the F(2) population, was not significant in the advanced lines. Oc2 and Oc3 were found to be associated with O. crenata resistance in at least two of the three environments, while the remaining two, Oc4 and Oc5, were only detected in Córdoba-04 and Mengíbar-04 and seemed to be environment dependent.

Gene expression analysis of molecular mechanisms of defense induced in Medicago truncatula parasitized by Orobanche crenata

The infection of Medicago truncatula Gaertn. roots with the obligate parasite Orobanche crenata Forsk. is a useful model for studying the molecular events involved in the legumes-parasite interaction. In order to gain insight into the identification of gene-regulatory elements involved in the resistance mechanism, the temporal expression pattern of ten defense-related genes was carried out using real-time quantitative reverse-transcription polymerase chain reaction assays. The induction of all of the analyzed transcripts significantly increased over a range from 2- to 321-fold higher than the control depending on the gene and time point. The transcriptional changes observed in response to O. crenata infection suggest that resistance could rely on both, the induction of general defense-related genes and more specific responses.

First Report of Orobanche crenata on Sulla (Hedysarum coronarium) in Andalusia, Southern Spain

Crenata broomrape (Orobanche crenata Forsk.), an obligate chlorophyll-lacking root parasite, is the major constraint for growing legume crops in infested soils in southern Spain. Peas (Pisum sativum L), faba beans (Vicia faba L.), and narbon bean (Vicia narbonensis L.) are seriously affected (1,2,4). However, no information is available regarding its ability to attack sulla (Hedysarum coronarium L.), which is an important fodder legume grown in rain-fed conditions, yielding as much as 10,000 kg/ha of dry matter. In 2008, we found broomrape shoots infecting 4 to 5% of sulla plants in a trial field (two land races, P-26 and P-3, in a 500-m² area) in Cordoba (Andalusia, southern Spain). The shoots developed numerous fertile flowering stalks throughout the field. The previous crop, narbon bean, was heavily infected during 2007 by O. crenata. Infection of sulla plants was confirmed by digging up the plant to verify the attachment of the broomrape plant to the sulla roots. The level of infection was low with only one to two emerged broomrape shoots per sulla plant infested. Morphology was typical of O. crenata. The calyx of the flowers was 13 to 18 mm long with free, bidentate segments. The white corolla of the flowers was 18 to 28 mm long and glandular pubescent. The lips were divergent, large, not ciliate, and filaments inserted 2 to 3 mm above the base of the corolla are hairy at base with glandular hair at the apex. The anthers were brown (3). Specimens were deposited in the Herbarium of the University of Córdoba (identification number COA 45358). To our knowledge, this first report of O. crenata parasitizing sulla shows that control methods for O. crenata will be needed if sulla is to be used as an alternative legume fodder in the infested soils of southern Spain. References: (1) J. I. Cubero and M. T. Moreno. Page 41 in: Some Current Research on Vicia faba in Western Europe. D. A. Bond et al., eds. Luxembourg, 1979. (2) S. Nadal et al. Plant Breed. 126:110, 2007. (3) A. J. Pujadas-Salvá. Page 187 in: Resistance to Orobanche: The State of the Art. Junta de Andalucía, Sevilla, Spain, 1999. (4) D. Rubiales et al. Crop Prot. 22:865, 2003.

Selection of housekeeping genes for normalization by real-time RT-PCR: analysis of Or-MYB1 gene expression in Orobanche ramosa development

Real-time PCR has become the method of choice for accurate and in-depth expression studies of candidate genes. To avoid bias, real-time PCR is referred to one or several internal control genes that should not fluctuate among treatments. A need for reference genes in the parasitic plant Orobanche ramosa has emerged, and the studies in this area have not yet been evaluated. In this study, the genes 18S rRNA, Or-act1, Or-tub1, and Or-ubq1 were compared in terms of expression stability using the BestKeeper software program. Among the four common endogenous control genes, Or-act1 and Or-ubq1 were the most stable in O. ramosa samples. In parallel, a study was carried out studying the expression of the transcription factor Or-MYB1 that seemed to be implicated during preinfection stages. The normalization strategy presented here is a prerequisite to accurate real-time PCR expression profiling that, among other things, opens up the possibility of studying messenger RNA levels of low-copy-number-like transcription factors.

Plant resistance to parasitic plants: molecular approaches to an old foe

Parasitic weeds pose severe constraint on major agricultural crops. Varying levels of resistance have been identified and exploited in the breeding programmes of several crops. However, the level of protection achieved to date is either incomplete or ephemeral. Resistance is mainly determined by the coexistence of several mechanisms controlled by multigenic and quantitative systems. Efficient control of the parasite requires a better understanding of the interaction and their associated resistance mechanisms at the histological, genetic and molecular levels. Application of postgenomic technologies and the use of model plants should improve the understanding of the plant-parasitic plant interaction and drive not only breeding programmes through either marker-assisted selection (MAS) or transgenesis but also the development of alternative methods to control the parasite. This review presents the current approaches targeting the characterization of resistance mechanisms and explores their potentiality to control parasitic plants.

The vascular surgeon facing clinical ethical dilemmas (the VASCUETHICS Study): 'V'-shaped association between compassionate attitudes and professional seniority

OBJECTIVE

To evaluate the association between compassionate attitudes and seniority in vascular surgeons facing clinical ethical dilemmas (CED).

SUBJECTS AND METHODS

(1) DESIGN: Cross-sectional. (2) SUBJECTS: Vascular surgeons (residents included) from the 28 vascular teaching departments of one European country. (3) MEASUREMENTS: Multidisciplinary team-designed, structured and self-administered questionnaire consisting of five clinical ethical dilemmas, of which four had conflict between compassion towards a 'small' or 'very costly' beneficial action vs. a reasonable but more 'pragmatic' allocation of health resources. Participants stated their degree of agreement with eight answers representing the two attitudes on a continuous scale. (4) STATISTICS: Cluster analysis and logistic regression model adjusted by confounding factors.

RESULTS

Two hundred and fifty three vascular surgeons (median age 37 years, 74% male) from the 26 participating teaching vascular departments (public hospitals) completed the questionnaire (88% surgeons/department). Cluster analysis identified two groups of surgeons according to their pattern of answers: Group I (n=63) were mainly compassionate whereas Group II (n=180) were mainly pragmatic. The multivariate analysis disclosed, after adjusting for additional private practice, on call services and career status, a significant V-shaped relationship between the compassionate behaviour and seniority. Surgeons with 8-15 years experience were the least compassionate.

CONCLUSIONS

The youngest and the most senior vascular surgeons were more prone to favour compassionate attitudes when facing clinical ethical dilemmas. Although both compassionate and pragmatic attitudes may be legitimate ethically, physicians not favouring compassion may be at risk of leaving the patient without an advocate within the health care system.

First Report of Orobanche foetida on Common Vetch (Vicia sativa) in Morocco

Broomrapes (Orobanche spp.) are obligate parasites that infect roots of dicotyledoneous plants. Orobanche spp. are particularly important in southern and eastern Europe, the Middle East, and north Africa. O. crenata causes severe damage to legume crops, O. cumana threatens sunflower, O. ramosa attacks potato, tobacco, tomato, and hemp, O. aegyptiaca is severe on legumes and vegetables, and other broomrapes such as O. minor are widespread on forage legumes (3). O. foetida Poir. is considered important as an agricultural parasite of faba bean (Vicia faba) and common vetch (V. sativa) crops in the Beja Region of Tunisia (1). Aside from that, it has never been found infecting crops, even where it is widely distributed in the western Mediterranean area (Portugal, Spain, Morocco, Algeria, and Tunisia) parasitizing wild herbaceous leguminosae in the genera Anthyllis, Astragalus, Ebenus, Lotus, Medicago, Ononis, Scorpiurus, and Trifolium (2). In May 2004, we found O. foetida commonly occurring in Morocco infecting wild leguminosae. It was not seen infecting legume crops such as faba beans, chickpeas, or lentils, even where O. foetida was abundant in the close proximity to the crop fields, or in the field itself. In these instances, we verified that O. foetida was infecting weeds such as Scorpiurus spp. and not the crop plants themselves by gently pulling out the plants and examining the roots. However, O. foetida was identified infecting common vetch (V. sativa) on a small farm in Taounate, Saiss Region, 50 km north of Fes. Infection of vetch plants was confirmed by digging up the plants to verify the attachment of the broomrape plant to the vetch roots. The level of infection was moderate (0.1 to 0.2 broomrape plants per vetch plant). The farmer stated that he had observed this problem only in the last 3 years. Morphology was typical of O. foetida, i.e., dark reddish plant, 20 to 50 cm tall, corolla 12 to 20 mm, dark, purplish-red, lower lip not ciliate, filaments inserted 3 to 7 mm above base of corolla, and stigma deep yellow at anthesis (2). Voucher specimens were deposited in the Herbarium of the University of Córdoba. To our knowledge, this is the first report of O. foetida infecting common vetch and it is relevant since it indicates the first introduction of this parasite into crops in Morocco. The spread of this new crop parasite population should be monitored because it could represent a further constraint for legume production in this area. References: (1) M. Kharrat et al. FABIS Newsl. 30:46, 1992. (2) A. J. Pujadas-Salvá. Pages 187-193 in: Resistance to Orobanche: The State of the Art. Junta de Andalucía, Spain, 1999. (3) D. Rubiales. Grain Legumes 33:10, 2001.

Clinical ethical dilemmas for vascular surgeons (the VASCUETHICS study): are self-interest attitudes related to professional seniority?

OBJECTIVE

To evaluate the association between professional seniority and self-interest (PSI) attitudes in the resolution of vascular ethical dilemmas (VED).

DESIGN

Cross-sectional.

SUBJECTS

Vascular surgeons (residents included) from the 28 vascular teaching departments of Spain. Measurements. Multidisciplinary team-designed questionnaire of 5 VED. Each VED had 3 different answers (attitudes): 2 favouring legitimate ethical attitudes (LEA) and 1 favouring PSI. The questionnaire was self-administered and all participants stated their degree of agreement with each answer on a continuous Likert scale. PSI was evaluated by: (1) adding the magnitudes of the 5 answers favouring PSI (absPSI); and (2) by comparing in each case the magnitude of the PSI answer with that of the 2 LEA (relPSI).

STATISTICS

Linear regression adjusted by confounding factors.

RESULTS

Two hundred and fifty-three vascular surgeons from the 26 participating teaching vascular departments of public hospitals completed the questionnaire (87.5% surgeons/department). Surgeon characteristics were: (1) median age 37 years; (2) 187 (74%) male; (3) 59 (23%) brought up with a health professional relative; (4) 94 (38%) had additional private practice; (5) 133 (65%) professed religious beliefs; and (6) 1-10 years of experience in 116 (47%), 11-20 years in 58 (24%), 21-30 years in 57 (23%), and >30 years in 15 (6%). The multivariate analysis disclosed that for every 10-years rise in professional seniority there was a 3.2% increase in absPSI (p=0.007, adjusted by variables 3 and 4), and a 3.4% increase in relPSI (p=0.002, adjusted by variable 5).

CONCLUSIONS

Professional seniority is associated with a slight increase in pro-PSI attitudes in cases of vascular ethical dilemma. Both vascular surgeons and health institutions should promote the reversal of this worrying tendency.

Development of a composite map in Vicia faba, breeding applications and future prospects

A composite map of the Vicia faba genome based on morphological markers, isozymes, RAPDs, seed protein genes and microsatellites was constructed. The map incorporates data from 11 F(2) families for a total of 654 individuals all sharing the common female parent Vf 6. The integrated map is arranged in 14 major linkage groups (five of which were located in specific chromosomes). These linkage groups include 192 loci and cover 1559 cM with an overall average marker interval of 8 cM. By joining data of a new F(2) population segregating for resistance to ascochyta, broomrape and others traits of agronomic interest, have been saturated new areas of the genome. The combination of trisomic segregation, linkage analysis among loci from different families with a recurrent parent, and the analysis of new physically located markers, has allowed the establishment of the present status of the V. faba map with a wide coverage. This map provides an efficient tool in breeding applications such as disease-resistance mapping, QTL analyses and marker-assisted selection.

Genetic relationships among Orobanche species as revealed by RAPD analysis

RAPD markers were used to study variation among 20 taxa in the genus OROBANCHE: O. alba, O. amethystea, O. arenaria, O. ballotae, O. cernua, O. clausonis, O. cumana, O. crenata, O. densiflora, O. foetida, O. foetida var. broteri, O. gracilis, O. haenseleri, O. hederae, O. latisquama, O. mutelii, O. nana, O. ramosa, O. rapum-genistae and O. santolinae. A total of 202 amplification products generated with five arbitrary RAPD primers was obtained and species-specific markers were identified. The estimated Jaccard's differences between the species varied between 0 and 0.864. The pattern of interspecific variation obtained is in general agreement with previous taxonomic studies based on morphology, and the partition into two different sections (Trionychon and Orobanche) is generally clear. However, the position in the dendrogram of O. clausonis did not fit this classification since it clustered with members of section TRIONYCHON: Within this section, O. arenaria was relatively isolated from the other members of the section: O. mutelii, O. nana and O. ramosa. Within section Orobanche, all O. ramosa populations showed a similar amplification pattern, whereas differences among O. crenata populations growing on different hosts were found. Orobanche foetida and O. densiflora clustered together, supporting the morphological and cytological similarities and the host preferences of these species.

Variation Among and Within Populations of the Parasitic Weed Orobanche crenata from Spain and Israel Revealed by Inter Simple Sequence Repeat Markers

ABSTRACT The patterns of genetic variation among Orobanche crenata populations from Spain and Israel were studied using radiolabeled inter simple sequence repeat amplification products that were separated in sequencing polyacrylamide gels. The analysis of molecular variance indicated that most of the genetic diversity was attributable to differences among individuals within a population although significant divergences were found between regions. The Jaccard's similarity matrix was analyzed by unweighted pair-group method with arithmetic average and the resultant dendrogram clearly divided six populations by region, with the Spanish populations being more similar to each other than the Israeli populations. These results are consistent with the predominantly allogamous behavior of O. crenata and the extremely efficient dispersal of its seeds.

Mapping of quantitative trait loci controlling broomrape (Orobanche crenata Forsk.) resistance in faba bean (Vicia faba L.)

Orobanche crenata Forsk. is a root parasite that produces devastating effects on many crop legumes and has become a limiting factor for faba bean production in the Mediterranean region. The efficacy of available control methods is minimal and breeding for broomrape resistance remains the most promising method of control. Resistance seems to be scarce and complex in nature, being a quantitative characteristic difficult to manage in breeding programmes. To identify and map the QTLs (quantitative trait loci) controlling the trait, 196 F2 plants derived from the cross between a susceptible and a resistant parent were analysed using isozymes, RAPD, seed protein genes, and microsatellites. F2-derived F3 lines were studied for broomrape resistance under field conditions. Of the 130 marker loci segregating in the F2 population, 121 could be mapped into 16 linkage groups. Simple interval mapping (SIM) and composite interval mapping (CIM) were performed using QTL Cartographer. Composite interval mapping using the maximum number of markers as cofactors was clearly the most efficient way to locate putative QTLs. Three QTLs for broomrape resistance were detected. One of the three QTLs explained more than 35% of the phenotypic variance, whereas the others accounted for 11.2 and 25.5%, respectively. This result suggests that broomrape resistance in faba bean can be considered a polygenic trait with major effects of a few single genes.