Review. Characterization and selection of hexaploid wheats containing resistance to Heterodera avenae or Mayetiola destructor introgressed from Aegilops

Cereal cyst nematode (CCN, Heterodera avenae) and Hessian fly (HF, Mayetiola destructor) are two major pests affecting wheat crops worldwide including important cereal areas of Spain. Aegilops ventricosa and Ae. triuncialis were used as donors in a strategy to introduce resistance genes (RG) for these pests in hexaploid wheat (Triticum aestivum L.). Two 42 chromosomes introgression lines have been derived from Ae. ventricosa: H-93-8 and H-93-33 carrying genes Cre2 and H27 conferring resistance to CCN and HF, respectively. Line TR-3531 with 42 chromosomes has been derived from Ae. triuncialis and carries RGs conferring resistance for CCN (Cre7) and for HF (H30). Alien material has been incorporated in lines H-93 by chromosomal substitution and recombination, while in line TR-3531 homoeologous recombination affecting small DNA fragments has played a major role. It has been demonstrated that Cre2, Cre7, H27 and H30 are major single dominant genes and not allelic of other previously described RGs. Biochemical and molecular-biology studies of the defense mechanism triggered by Cre2 and Cre7 have revealed specific induction of peroxidase and other antioxidant enzymes. In parallel to these basic studies advanced lines carrying resistance genes for CNN and/or HF have been developed. Selection was done using molecular markers for eventually «pyramiding» resistance genes. Several isozyme and RAPD markers have been described and, currently, new markers based on transposable elements and NBS-LRR sequences are being developed. At present, two advanced lines have already been included at the Spanish Catalogue of Commercial Plant Varieties.

Consumer resistance to mobile commerce services

Oheinen opinnäytetyö on kvalitatiivinen tutkimus kuluttajavastarinnasta mobiilin kaupankäynnin palveluja kohtaan. Tutkimus kohdistuu läntisiin kulttuureihin, joissa kyseisen innovatiivisen palveluryhmän leviämistä tukevat monet aikaisemmat innovaatiot kuten matkapuhelin, Internet, digitaaliset pankkipalvelut. Tutkimus esittelee innovaatioiden vastarintatekijöitä ihmisen luonnollisena reaktiona tämän vakiintuneita elämäntapoja mullistavia keksintöjä kohtaan nimenomaan läntisissä kulttuureissa, joissa kuluttajat ovat perinteisesti hyvin teknologiamyönteisiä. Toisaalta tutkimusalueella on havaittavissa sosiaalisten ryhmien pirstoutuminen yhä pienemmiksi alaryhmiksi, mikä voi hidastaa sosiaalista oppimista. Tutkimus vastaa todelliseen tutkimusaukkoon. Aihe on samalla sekä ajankohtainen että relevantti vastatessaan nykyisin käytävään utopistiseen keskusteluun digitaalisen informaatioyhteiskunnan kehittymisestä ja merkityksestä modernille ihmiskunnalle. Tutkimuksen teoreettinen eksploratiivinen viitekehys rakentuu valikoiduista uusien tuotteiden ja palvelujen kehittämisen, palvelumarkkinoinnin ja sosiaalisen oppimisen teorioista sekä innovaatio- kommunikaatioteorioista. Empiirisen osan muodostavat kansainvälisten markkinatutkimuslaitosten ja haastateltujen asiantuntijoiden näkemykset alan kehityksestä. Tutkimus osoittaa, että kuluttajat eivät ole valmiita vastaanottamaan kehittyvien teknologioiden mahdollistamia mobiilin kaupankäynnin palveluita ennen kuin ne vastaavat kuluttajien perustarpeisiin ja rakenteelliset vastarintatekijät (alhainen käytettävyys, matala lisäarvo, koetut riskit, perinnevastarinta, palveluryhmän huono mielikuva) on poistettu. Tutkimus esittää, että mobiilin kaupankäynnin alalla toimivien yritysten tulisi työskennellä yhteistyössä keskenään ja kuluttajien kanssa luodakseen kuluttajien tarpeita ja toiveita vastaavia turvallisiksi koettuja mobiilin kaupankäynnin palveluita. Tutkimus ehdottaa, että kyselytutkimusten ohella käytettäisiin havaintomenetelmiä, jotta teknologiat voitaisiin valjastaa kuluttajien tarpeita ja kulutustottumuksia vastaaviksi.

Clopidogrel Pharmacogenetics, resistance to antiplatelet therapy in ischemic stroke by Epigenome Wide Association Study (EWAS).

Clopidogrel is a widely used antiplatelet drug used in preventing vascular events after suffering a first stoke. Genome-wide association studies (GWAS) has not been able to establish a clear association between polymorphisms and recurrence. Therefore in the present final master project an epigenetic approach is proposed. Using an array based technology, 450.000 CpG sites across all genome were assessed in 48 individuals (21 cases and 21 controls). Looking at differentially methylated levels between cases and controls, 58 CpG sites (DMGs) were found. Although, no clear locus was observed. Looking individually to each 49 genes, two appeared to be important to our study. TRAF3 and ADAMTS2 are gens highly related to platelet aggregation. In orther to confirm these result, a new DNA methylation study will be done in a larger cohort, using Sequenom technology.

Snail blocks the cell cycle and confers resistance to cell death

The Snail zinc-finger transcription factors trigger epithelial-mesenchymal transitions (EMTs), endowing epithelial cells with migratory and invasive properties during both embryonic development and tumor progression. During EMT, Snail provokes the loss of epithelial markers, as well as changes in cell shape and the expression of mesenchymal markers. Here, we show that in addition to inducing dramatic phenotypic alterations, Snail attenuates the cell cycle and confers resistance to cell death induced by the withdrawal of survival factors and by pro-apoptotic signals. Hence, Snail favors changes in cell shape versus cell division, indicating that with respect to oncogenesis, although a deregulation/increase in proliferation is crucial for tumor formation and growth, this may not be so for tumor malignization. Finally, the resistance to cell death conferred by Snail provides a selective advantage to embryonic cells to migrate and colonize distant territories, and to malignant cells to separate from the primary tumor, invade, and form metastasis.

Genetic linkage map of Phaseolus vulgaris and identification of QTLs responsible for resistance to Xanthomonas axonopodis pv. phaseoli

Common bean (Phaseolus vulgaris) cultivars with a high degree of resistance to Xanthomonas axonopodis pv. phaseoli (Xap) are not available in Brazil. Despite many studies, a low degree of resistance to Xap continues to exist due to its complex genetic inheritance, which is not well known. The objectives of this research were to complement a common bean genetic map based on the cross between a susceptible genotype 'HAB-52' and a resistant genotype 'BAC-6', and to map and analyze genomic regions (quantitative trait loci – QTLs) related to Xap resistance. Eleven linkage groups were determined using 143 RAPD markers, covering 1,234.5 cM of the genome. This map was used to detect QTLs associated with Xap resistance on leaves and pods. The averages of disease severity on leaves (represented by the transformed disease index – TDI) and pods (represented by the diameter of lesion on pods – DLP) were added to the data of the linkage map. Five TDI QTLs and only one LDP QTL were detected. The TDI QTLs were placed in the A, B, G and J linkage groups, with phenotypic variations ranging from 12.7 to 71.6%. The DLP QTL explained 12.9% of the phenotypic variation and was mapped in a distinct linkage group. These results indicate that there are different genes involved in the control of resistance on leaves and pods.

Resistance to Meloidogyne mayaguensis in Psidium spp. Accessions and their grafting compatibility with P. guajava cv. Paluma

Meloidogyne mayaguensis has been reported in some states of Brazil causing severe damage on commercial guava (Psidium guajava L.). Accessions of Psidium spp. were selected from a collection maintained in Embrapa Clima Temperado (Pelotas, Rio Grande do Sul State). Plants of different accessions were grown from seed in plastic bags and, when they reached 15-20 cm in height, were inoculated with 10,000 eggs/plant of M. mayaguensis. Eight months after inoculation, the different accessions were evaluated for resistance to M. mayaguensis. Three accessions of P. guajava were highly susceptible (RF=59.2) to this nematode. Psidium friedrichsthalianium was considered to be moderately resistant (RF=1.9). Three accessions of P. cattleyanum were immune to M. mayaguensis (RF = 0). When used as rootstocks P. cattleyanum and P. friedrichsthalianium were compatible with P. guajava cv. Paluma. Considering these results, the use of resistant rootstocks provides a promising control method for M. mayaguensis in commercial guava crop.

Evaluation of phenotypic stability of resistance to Phytophthora spp. in cacao clones

Resistance of fourteen Theobroma cacao clones to Phytophthora spp. was evaluated using stem inoculations on grafted seedlings. Concepts of phenotypic stability were used to interpret the results and to express horizontality of the resistance. The linear regression coefficient 'b', the determination coefficient (R²) and average lesion size were used to determine the level of horizontal resistance, the phenotypic stability and the predictability of all clones. The results indicated that clones P 7 and MA 15 present highest levels of horizontal resistance and stability, but with moderate predictability. Clones CAS 1 and CEPEC 13 were classified as those with high horizontal resistance, stability and predictability, while clones PA 30, UF 650 and SIAL 88 and EET 59 showed intermediate resistance and stability and high predictability. Clones SPA 17, OC 61, PA 150, SIAL 505, ICS 1 and R 41 presented high susceptibility and intermediate or low stability and moderate or high predictability.

Cotton resistance to ramulose and variability of Colletotrichum gossypii f. sp. cephalosporioides

Four cultivars and 21 lines of cotton were evaluated for resistance to ramulose (Colletotrichum gossypii f. sp. cephalosporioides) in a field where the disease is endemic. The seeds of each genotype were planted in 5 x 5 m plots with three replications. The lines CNPA 94-101 and 'CNPA Precoce 2'were used as standard susceptible and resistant references, respectively. The disease incidence (DI) was calculated from the proportion of diseased plants in the plot. The disease index (DIn) was calculated from the disease severity using a 1 to 9 scale, and was evaluated at weekly intervals starting 107 days after emergence. The data collected was used to calculate the area under disease progress curve (AUDPC). In general, the DIn increased linearly with time and varied from 20.0 to 57.1 and AUDPC from 567 to 1627 among the genotypes which could be clustered in to two distinct groups. The susceptible group contained two cultivars and nine lines and the resistant group contained one cultivar and 12 lines. The relationship between disease index and evaluation times was linear for the 25 genotypes tested. The line CNPA 94-101, used as susceptible standard, was the most susceptible with an average DI = 83.4, DIn = 57.1 and AUDPC = 1627.7. The line CNPA 96-08 with DI = 37.8, DIn = 20.0 and AUDPC = 567.7 was the most resistant one. Among the commercial cultivars 'IAC 22' was the most susceptible and 'CNPA Precoce 2', used as resistant standard was the most resistant. The variability in virulence of the pathogen was studied by spray inoculating nine genotypes with conidial suspensions (10(5)/mL) of either of the 10 isolates. The disease severity was evaluated 30 days later using a scale of 1 to 5. The virulence of the isolate was expressed by DIn. All the isolates were highly virulent but their virulence avaried for several genotypes and could be clustered in two distinct groups of less and more virulent isolates. The isolate MTRM 14 from Mato Grosso was the least virulent while Minas Gerais was the most virulent, with DIn of 6.36 and 46.47, respectively. In this experiment the line HR 102 and the cultivar 'Antares' were the most resistant ones with DIns of 18.32 and 19.14, respectively.

Net melon resistance to Didymella bryoniae according to grafting and potassium levels

Chemical control of the fungus Didymella bryoniae, the causal agent of the disease gummy stem blight in melon, is frequently inefficient; thus, alternatives such as grafting and nutrition must be studied. Rootstocks and potassium levels were tested aimed at controlling this disease in net melon under protected environment. The melon hybrid 'Bônus II', ungrafted and grafted onto 'Dinero' melon and 'Strong Tosa' pumpkin rootstocks, was cultivated and inoculated by using the toothpick insertion method with 7-mm mycelial disks from the isolate D. bryoniae Dbr 37; for control, only toothpick insertion was used. The plants were subjected to the following potassium levels: 0, 62.5, 125, 187.5, 250 mg L-1. Grafted 'Bônus II' melon plants were resistant to the fungus, whereas ungrafted ones were susceptible. The adopted potassium levels did not influence the stem lesion size or the survival of plants.

Relationship of intestinal histology with the resistance to Trichostrongylus colubriformis infection in three breeds of sheep

The study was carried out to evaluate the relationship of inflammatory intestinal cells with the resistance to Trichostrongylus colubriformis infections in three breeds of sheep (Santa Ines, Suffolk and Ile de France), naturally infected. Mast cells, eosinophils, and globule leucocytes were enumerated in intestinal mucosa. Histamine concentration was estimated in intestinal tissue samples and the length of male and female specimens were determined. The three breeds of sheep showed similar cellular response in the small intestine mucosa (P>0.05). There was extensive variation among sheep in the parasitological and inflammatory cell variables, even in lambs of the same breed. In general, animals presenting less inflammatory cells had a larger worm burden, higher fecal egg counts, and larger T. colubriformis worms. The inflammatory cells possibly impaired the parasite's establishment, development, and survival.

Resistance to β-lactam and tetracycline in Campylobacter spp.isolated from broiler slaughterhouses in southern Brazil

Abstract The study was carried out to screen and analyze the genetic characteristics of antimicrobial resistance in Campylobacter spp. from poultry sources. A total of 141 strains of Campylobacter isolated from samples of broilers of slaughterhouses in southern Brazil was identified by phenotypic and genotypic methods. Campylobacter isolates were evaluated for its antimicrobial susceptibility and the presence of resistance genes. The strains were investigated for antimicrobial susceptibility against two agents (ampicillin and tetracycline) by disk diffusion method. PCR assay was used to confirm the specie and the presence of ampicillin (blaOXA-61), tetracycline tet(O), and the energy-dependent multi-drug efflux pump (cmeB) genes. Campylobacter jejuni was the most ubiquitous; its presence was determined in 140 samples out of 141 (99.3%), whereas Campylobacter coli was found only in one of the contaminated samples (0.70%). The results obtained showed 65% and 35.5% of Campylobacter isolates resistant to β-lactams and tetracyclines, respectively. The cmeB gene responsible for multidrug resistance was detected in 26 isolates out 141 strains (18.5%). Moreover, 36 out of 141 Campylobacter strains (25.6%) were found to be resistant to at least two different antimicrobia resistance markers (β-lactams and tetracyclines).

Resistance to ACCase inhibitors in Eleusine indica from Brazil involves a target site mutation

Eleusine indica (goosegrass) is a diploid grass weed which has developed resistance to ACCase inhibitors during the last ten years due to the intensive and frequent use of sethoxydim to control grass weeds in soybean crops in Brazil. Plant dose-response assays confirmed the resistant behaviour of one biotype obtaining high resistance factor values: 143 (fenoxaprop), 126 (haloxyfop), 84 (sethoxydim) to 58 (fluazifop). ACCase in vitro assays indicated a target site resistance as the main cause of reduced susceptibility to ACCase inhibitors. PCR-generated fragments of the ACCase CT domain of the resistant and sensitive reference biotype were sequenced and compared. A point mutation was detected within the triplet of aspartate at the amino acid position 2078 (referred to EMBL accession no. AJ310767) and resulted in the triplet of glycine. These results constitute the first report on a target site mutation for a Brazilian herbicide resistant grass weed.

Rapid diagnosis of resistance to imidazolinone herbicides in barnyardgrass (Echinochloa crus-galli) and control of resistant biotypes with alternative herbicides

The resistance of barnyardgrass (Echinochloa crus-galli) to imidazolinone herbicides is a worldwide problem in paddy fields. A rapid diagnosis is required for the selection of adequate prevention and control practices. The objectives of this study were to develop expedite bioassays to identify the resistance to imidazolinone herbicides in barnyardgrass and to evaluate the efficacy of alternative herbicides for the post-emergence control of resistant biotypes. Three experiments were conducted to develop methods for diagnosis of resistance to imazethapyr and imazapyr + imazapic in barnyardgrass at the seed, seedling and tiller stages, and to carry out a pot experiment to determine the efficacy of six herbicides applied at post-emergence in 13 biotypes of barnyardgrass resistant to imidazolinones. The seed soaking bioassay was not able to differentiate the resistant and susceptible biotypes. The resistance of barnyardgrass to imidazolinones was effectively discriminated in the seedlings and tiller bioassays seven days after incubation at the concentrations of 0.001 and 0.0001 mM, respectively, for both imazethapyr and imazapyr + imazapic. The biotypes identified as resistant to imidazolinones showed different patterns of susceptibility to penoxsulam, bispyribac-sodium and pyrazosulfuron-ethyl, and were all controlled with profoxydim and cyhalofop-butyl. The seedling and tiller bioassays are effective in the diagnosis of barnyardgrass resistance to imidazolinone herbicides, providing an on-season opportunity to identify the need to use alternative herbicides to be applied at post-emergence for the control of the resistant biotypes.