Avaliação da resistência de cultivares de feijoeiro (Phaseolus spp.) a Meloidogyne javanica, para uso como porta-enxerto

Das diversas pragas e doenças que afetam o feijoeiro (Phaseolus spp.), encontram-se os nemátodes-das-galhas-radiculares (NGR), Meloidogyne spp., sendo amplamente conhecido o seu efeito devastador em culturas hortícolas. A principal estratégia de controlo assenta na aplicação de nematodicidas, que têm sido progressivamente restringidos. Têm sido consideradas técnicas de controlo alternativas, como a enxertia de hortícolas em porta-enxertos resistentes. Os objetivos do estudo foram: 1) conhecer a reação de cultivares de feijoeiro (Phaseolus vulgaris e P. coccineus) a Meloidogyne javanica, considerando o seu grau de suscetibilidade ou resistência; 2) avaliar a severidade dos danos causados nas raízes; e 3) inferir sobre a potencial utilização destas cultivares como porta-enxerto comercial de feijoeiro. Foi realizado um ensaio em vaso, com cinco repetições de cada uma de nove cultivares testadas, que decorreu numa sala de culturas com condições controladas. As plantas foram inoculadas com 5000 ovos e jovens de M. javanica; plantas não inoculadas serviram de testemunha negativa, sendo a testemunha positiva plantas de tomateiro cv. Tiny Tim reconhecidamente suscetível a M. javanica. Sessenta dias após a inoculação, procedeu-se à determinação do número de galhas e de massas de ovos nas raízes. Nenhuma das cultivares testadas foi completamente resistente ao nemátode. No entanto, através de uma análise comparativa, foi detetado um potencial de resistência nas cultivares Bencanta e Oriente, em que foram registados níveis do número de galhas, de massas de ovos e de reprodução dos nemátodes comparáveis aos de cultivares classificadas como resistentes. As cultivares Bencanta e Oriente revelaram resultados promissores relativamente à sua utilização como porta-enxertos resistentes a NGR, justificando-se uma investigação mais aprofundada para testar e avaliar a viabilidade da sua utilização na enxertia de feijoeiro, em condições controladas e no campo, e na presença de outras espécies de NGR.Evaluation of the resistance of common bean (Phaseolus spp.) to Meloidogyne javanica, for use as rootstocks. Among the numerous pests and diseases that affect common bean (Phaseolus spp.), root-knot nematodes (RKN), Meloidogyne spp., are the ones that stand out for their devastating effects on horticultural crops. The main control strategy is based on the application of nematicides, which have been 1 progressively restricted. Alternative nematode management methods have been considered, such as vegetable grafting using resistant cultivars. The objectives of this study were: 1) to know the reaction of nine cultivars of common bean (Phaseolus vulgaris and P. coccineus) to Meloidogyne javanica, considering their degree of susceptibility and resistance; 2) to assess the severity of damage to the roots; and 3) to infer on the potential use of these cultivars as commercial bean rootstocks. A pot experiment was done under controlled conditions in a culture room, and each treatment consisted of five replicates. Plants were inoculated with 5000 eggs and second stage juveniles of M. javanica, with uninoculated plants serving as negative control and susceptible tomato plants cv. Tiny Tim being used as positive control. Sixty days after inoculation, roots were observed to determine the number of galls and egg masses. None of the tested cultivars was completely resistant to the nematode. However, through a comparative analysis, a potential for resistance was detected in Bencanta and Oriente cultivars, with levels of nematode-induced galls and egg masses comparable to those of cultivars classified as resistant. The Bencanta and Oriente cultivars showed promising results regarding their use as resistant rootstocks to RKN, justifying further research to test and assess the feasibility of their use in bean grafting, under controlled conditions and in the field, and in the presence of other species of RKN.Programa Estratégico UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569), financiado por fundos nacionais através da Fundação para a Ciência e a Tecnologia, e pelo Fundo Europeu de Desenvolvimento Regional (FEDER), através do COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI)Empresa Alípio Dias & Irmão LdaEmpresa Tozer Iberica SLEscola Superior Agrária de Ponte de LimaLaboratório de Nematologia da Universidade de Coimbrainfo:eu-repo/semantics/publishedVersio

Dynamics of river plumes in the South Brazilian Bight and South Brazil

Research articleThe plumes from the rivers of the South Brazilian Bight (SBB) and South Brazil (SB) were studied using a realistic model configuration. River plume variability on continental shelves is driven by the input of river runoff into the shelf, by wind variability, and also by ambient currents and its seasonal variability, especially the Brazil Current, which are realistically modelled in this study. It is presented a simulation of 4 years using a nested configuration, which allows resolving the region around Florianópolis with very high resolution (∼150 m). The dispersion of river plumes was assessed not only with the hydrodynamical model results but also by using passive tracers whose dynamics was analyzed seasonally. Several dyes were released together with the river discharges. This approach allowed calculating the depths of the riverine freshwater, and the resulting regions affected by the plumes. Northward intrusions of waters from the southern region, under the potential influence of the distant La Plata river plume, were evaluated with a Lagrangian approach. The local river plumes are confined to the inner shelf, except south of 30°S where discharges from Lagoa dos Patos disperse over the shelf in the spring and summer. The Brazil Current flowing southward over the slope prevents the river plumes from interaction with oceanic mesoscale dynamics. The river plumes are, thus, mainly controlled by the wind forcing. The plumes from SBB are able to disperse until SB following the southward wind regime typical of the summer. And both the SB and La Plata river plumes are also able to reach SBB, forced by the northward wind typical of the winter season, until the latitude of 25.5°S. A low salinity belt (below 35) is present along the coastal region of SB and SBB year-round, supported by contributions from both the large and small rivers. The interaction between the different plumes influences the dispersion patterns, shielding the Florianṕolis coastal region from plumes of distant rivers, and dispersing the plume of SBB rivers away from Santa Catarina Island as it disperses southward during the summer months.Versión del edito

Daily parental knowledge of youth activities is linked to youth physical symptoms and HPA functioning.

Considerable evidence documents linkages between parental knowledge of youth activities and youth risky behavior. We extended this research to determine whether parental knowledge was associated with youth physical health, including reports of physical symptoms (e.g., headaches, stomachaches) and a biomarker of hypothalamic pituitary adrenocortical (HPA) axis functioning (i.e., salivary cortisol levels). Participants were children of employees in the Information Technology division of a Fortune 500 company (N = 132, Mean Age Youth = 13.39 years, 55% female) who participated in a daily diary study. Data were collected via telephone calls on eight consecutive evenings. On four study days, cortisol samples were collected at 4 time points (waking, 30 min after waking, before dinner, bedtime). Multi-level models revealed that, at the between-person level, youth whose parents had higher average knowledge about their activities, exhibited lower bedtime cortisol levels. Furthermore, at the within-person level, on days when parents displayed more knowledge than usual (relative to their own eight-day average), youth had lower before-dinner cortisol than usual. Linkages between average parental knowledge and physical health symptoms were moderated by youth age: Younger but not older adolescents whose parents were more knowledgeable had fewer physical health symptoms, on average. A next step is to identify the processes that underlie these associations

Daily stressor reactivity during adolescence: The buffering role of parental warmth.

This study examined youth stressor reactivity in the form of links between daily stressors and adolescents’ negative affect, physical health symptoms, and cortisol patterns. We also tested whether youth gender and parental warmth moderated these linkages

Neighborhood Features and Physiological Risk: An Examination of Allostatic Load

Poor neighborhoods may represent a situation of chronic stress, and may therefore be associated with health-related correlates of stress. We examined whether lower neighborhood income would relate to higher allostatic load, or physiological well-being, through psychological, affective, and behavioral pathways. Using data from the Biomarker Project of the Midlife in the United States (MIDUS) study and the 2000 Census, we demonstrated that people living in lower income neighborhoods have higher allostatic load net of individual income. Moreover, findings indicate that this relation is partially accounted for by anxious arousal symptoms, fast food consumption, smoking, and exercise habits

Neighborhood Cohesion and Daily Well-Being: Results from a Diary Study

Neighborly cohesiveness has documented benefits for health. Furthermore, high perceived neighborhood cohesion offsets the adverse health effects of neighborhood socioeconomic adversity. One potential way neighborhood cohesion influences health is through daily stress processes. The current study uses participants (n = 2022, age 30–84 years) from The Midlife in the United States II and the National Study of Daily Experiences II, collected between 2004 and 2006, to examine this hypothesis using a within-person, daily diary design. We predicted that people who perceive high neighborhood cohesion are exposed to fewer daily stressors, such as interpersonal arguments, lower daily physical symptoms and negative affect, and higher daily positive affect. We also hypothesized that perceptions of neighborhood cohesion buffer decline in affective and physical well-being on days when daily stressors do occur. Results indicate that higher perceived neighborhood cohesion predicts fewer self-reported daily stressors, higher positive affect, lower negative affect, and fewer physical health symptoms. High perceived neighborhood cohesion also buffers the effects of daily stressors on negative affect, even after adjusting for other sources of social support. Results from the present study suggest interventions focusing on neighborhood cohesion may result in improved well-being and may minimize the adverse effect of daily stressors