Many coral reefs worldwide have undergone phase shifts to alternate, degraded assemblages because of the combined effects of over-fishing, declining water quality, and the direct and indirect impacts of climate change. Here, we experimentally manipulated the density of large herbivorous fishes to test their influence on the resilience of coral assemblages in the aftermath of regional-scale bleaching in 1998, the largest coral mortality event recorded to date. The experiment was undertaken on the Great Barrier Reef, within a no-fishing reserve where coral abundances and diversity had been sharply reduced by bleaching. In control areas, where fishes were abundant, algal abundance remained low, whereas coral cover almost doubled (to 20%) over a 3 year period, primarily because of recruitment of species that had been locally extirpated by bleaching. In contrast, exclusion of large herbivorous fishes caused a dramatic explosion of macroalgae, which suppressed the fecundity, recruitment, and survival of corals. Consequently, management of fish stocks is a key component in preventing phase shifts and managing reef resilience. Importantly, local stewardship of fishing effort is a tractable goal for conservation of reefs, and this local action can also provide some insurance against larger-scale disturbances such as mass bleaching, which are impractical to manage directly.

No abstract

A diversificação de uso de porta-enxertos de citros é importante no Brasil devido à presença de diversos estresses abióticos e bióticos, além da busca por atributos horticulturais desejáveis como nanismo, alta eficiência de produção e indução de boa qualidade aos frutos. Para a seleção de um genótipo com potencial de uso como porta-enxerto, porém, o desempenho na fase de propagação também é relevante. Assim, caracterizaram-se os frutos e avaliou-se a propagação em ambiente protegido de porta-enxertos híbridos de citros obtidos ou selecionados pelo Programa de Melhoramento Genético de Citros da Embrapa: citrandarins ‘Indio’, ‘Riverside’ e ‘San Diego’, híbridos HTR-051, TSKC x (LCR x TR)-040 e 059, LVK x LCR-010 e 038, TSKC x CTTR-002, TSKC x CTSW-041 e LCR x TR-001, além das variedades comerciais citrumelo ‘Swingle 4475’, trifoliata ‘Flying Dragon’, limoeiro ‘Cravo Santa Cruz’ e tangerineira ‘Sunki Tropical’. Foram avaliados variáveis biométricas, fisiológicas e coeficientes técnicos. O delineamento experimental foi em blocos ao acaso, com quatro repetições e 50 plantas na parcela ou 20 frutos por genótipo, conforme a avaliação. Citrumelo ‘Swingle’ e LVK x LCR-010 apresentaram alta produção de sementes por fruto, enquanto HTR-051 e LCR x TR-001 produziram as menores quantidades. A poliembrionia foi superior para TSKC x CTTR-002, TSKC x (LCR x TR)–040, LCR x TR-001, citrandarins ‘Indio’, ‘Riverside’ e ‘San Diego’ e tangerineira ‘Sunki Tropical’, tendo trifoliata ‘Flying Dragon’ e LVK x LCR-010 apenas 45% de poliembrionia média. A emergência de citrandarin ‘Riverside’ foi mais rápida e uniforme em relação aos demais genótipos. O crescimento vegetativo da parte aérea e do sistema radicular foi superior para citrandarin ‘Riverside’, TSKC x (LCR x TR)-059, tangerineira ‘Sunki Tropical’, citrumelo ‘Swingle’ e limoeiro ‘Cravo’ e seus híbridos. Todos os híbridos de citros avaliados apresentam potencial de uso como porta-enxertos.

No abstract

To estimate the quality of coastal waters, European Union Directive 2006/7/EC provides guidelines to assess levels of faecal bacteria, including Escherichia coli and intestinal enterococci. These microbiological criteria are based on studies that determine the risk of bathers having diseases caused by enteric bacteria, not necessarily measuring the potential danger associated with the presence of nonenteric pathogens. The association between the presence of faecal contaminant indicators and nonenteric pathogenic microorganisms has not been well defined yet. The purpose of this study is to establish a relationship between Pseudomonas aeruginosa and microbiological indicators of faecal contamination. Presence of microbiological contamination in the coastal waters near the sewage treatment plant (STP) of Peniche (Portugal) was confirmed (P. aeruginosa 135.8 Colony Forming Unit/100 mL, Escherichia coli 1100.1 Most Probable Number/100 mL, intestinal enterococci 2685.9 MPN/100 mL) with much lower levels in the areas located south of the STP, along the main water coastal current (beach 1: 0.7 CFU/100 mL, 16.5 MPN/100 mL, 100.5 MPN/100 mL; beach 2: 0.3 CFU/100 mL, 74.0 MPN/100 mL, 145.9 MPN/100 mL, respectively). Analysis of Pearson's correlation revealed a strong positive correlation between E. coli and P. aeruginosa, suggesting E. coli as an indicator of P. aeruginosa presence.Pathogens 2020, 9, 13 2 of 10 throat diseases [11]. These indicators were based on conclusions from epidemiological studies that implicate the enteric bacteria E. coli and enterococci in cases of gastroenteritis associated with swimming. However, the majority of recently reported cases of infectious diseases linked with coastal bathing waters are of nonenteric origin [12], creating a requirement for nonenteric indicator organisms that must be additionally evaluated. Opportunistic bacteria, such as Pseudomonas aeruginosa [13], might better serve to indicate the occurrence of some of the nonfaecal pathogens [12], especially in bathing waters [14]. Taking into account the results found in a study from Mariño and coworkers, where a positive correlation was found between skin infections and the presence of P. aeruginosa in seawater [14], this opportunistic bacteria [13] might better serve to indicate the occurrence of some nonfaecal pathogens in bathing waters [12].Being rod-shaped, gram-negative, facultative aerobic bacterium, P. aeruginosa has minimal survival requirements [15,16] and a remarkable adaptation ability towards a variety of environmental conditions, being able to thrive in soil, water, animal hosts, hospital settings, soap, and even distilled water [17][18][19][20]. P. aeruginosa, as the origin of an extensive variety of infections, is a main cause of illness in immunocompromised individuals [21]. Some examples are endocarditis, urinary tract infections, pneumonia, gastrointestinal infections, and meningitis, and it is also a leading cause of septicaemia [19]. P. aeruginosa is the pathogen mostly implicated in folliculitis and ear infec...

RESUMO O objetivo deste trabalho foi avaliar a produção de mudas de laranjeiras doces ‘Pera’ e ‘Westin’, tangerineira-tangor ‘Piemonte’ e limeira-ácida ‘Tahiti’ enxertadas em 14 porta-enxertos de citros em viveiro protegido. As mudas de laranjeiras-doces ‘Pera D-6’ e ‘Westin’, tangerineira-tangor ‘Piemonte’ e limeira-ácida ‘Tahiti CNPMF-02’ foram avaliadas em viveiro protegido após a enxertia, em 11 porta-enxertos híbridos: citrandarins ‘Indio’, ‘Riverside’ e ‘San Diego’, citrumelo ‘Swingle 4475’, HTR-051, TSKC x (LCR x TR)-040 e 059, LVK x LCR-010 e 038, TSKC x CTTR-002 e TSKC x CTSW-041, além de trifoliata ‘Flying Dragon’, limoeiro ‘Cravo Santa Cruz’ e tangerineira ‘Sunki Tropical’. Coletaram-se variáveis biométricas e fisiológicas, sendo o delineamento experimental em blocos ao acaso, em parcelas subdivididas, com 56 tratamentos, três repetições e dez plantas na parcela. Independentemente do porta-enxerto, a limeira-ácida ‘Tahiti CNPMF-02’ foi a copa mais vigorosa em viveiro, seguida da tangerineira-tangor ‘Piemonte’ e, por fim, pelas laranjeiras ‘Pera-D6’ e ‘Westin’. A tangerineira ‘Sunki Tropical’ induziu maior crescimento vegetativo e de sistema radicular em combinação com todas as copas estudadas. O trifoliata ‘Flying Dragon’ e o híbrido HTR-051 necessitam de maior período para a formação das mudas em função do menor vigor desses genótipos, em combinação com todas as variedades copas avaliadas. Não se observaram quaisquer sintomas de incompatibilidade entre as variedades no viveiro.

The objective of this work was to select rootstocks, based on the agronomic characters and fruit quality of the 'Valência' orange tree. The evaluated rootstocks were: the 'Cleópatra' mandarin; the TSKFL x CTTR-013, LVK x LCR-038, TSKC x CTQT 1439-004, LVK x LVA-009, TSK x TRENG-256 ('Indio' citrandarin) hybrid genotypes; the 'Santa Cruz' Rangpur lime; and the TSKFL x CTC-25-002, and TSKC x CTSW-038 hybrids. The experiment was installed in 2010 and evaluated from 2013 to 2017. The parameters plant height, canopy volume, yield efficiency, scion:rootstock ratio, survival percentage, and drought tolerance were evaluated in 2017. The yield average of five harvests was estimated, as well as the annual production per plant and the accumulated production. The analyzed fruit traits were: mass, diameter, peel length and thickness, juice yield, soluble solids, acidity, and technological index. 'Valência' shows a lower plant height and canopy volume, besides a higher yield efficiency, when grafted on TSKC x CTSW-038 than on the other rootstocks. LVK x LCR-038, TSKC x CTQT 1439-004, 'Indio' citrandarin, and 'Santa Cruz' Rangpur lime increase the production of the 'Valência' orange. LVK x LCR-038 and the 'Indio' citrandarin induce the scion to produce a better quality fruit.

The aim of this work was to evaluate the effect of mulch on clay loam and sandy loam soils on the start harvest, number of fruits per plant, yield and quality of yellow passion fruits in organic crop. A complete randomized block design with five treatments and four replicates of five plants each was used. Treatments corresponded to different percentages of mulch of the area occupied by the plant (3 x 3 m), extending from the center of the planting line to the planting row in 0% without mulch (T1); 25% (T2); 50% (T3); 75% (T4) and 100% (T5). Mulch anticipated the harvest in comparison to crop in uncovered soil in both types of soil. The number of fruits per plant and yield increased in a quadratic function with maximum point of 38.6 fruits plant -1 and 5,182.0 kg ha -1 with 75.7% and 78.0% of soil cover, respectively. Mulch on clay loam soil did not provide increase in the average fruit mass and did not change the quality of fruits in relation to control fruits. Index terms: Passiflora edulis f. flavicarpa Degener, soil texture, fruit quality, organic fruit crop. Desempenho do maracujazeiro-amarelo em cultivo orgânico sob cobertura mortaResumo -O objetivo deste trabalho foi avaliar o efeito da cobertura morta em solo franco-argiloso e franco-arenoso sobre o tempo necessário para início da produção, número de frutos por planta, produtividade e qualidade dos frutos do maracujazeiro-amarelo em cultivo orgânico. Utilizou-se o delineamento experimental de blocos inteiramente casualizados, com cinco tratamentos e quatro repetições de cinco plantas cada. Os tratamentos corresponderam a diferentes porcentagens de cobertura morta da área ocupada pela planta (3 x 3 m) se estendendo do centro da linha de plantio para a rua em 0% sem cobertura (T1); 25% (T2 ); 50% (T3); 75% (T4) e 100% (T5). A cobertura do solo foi aplicada em faixa contínua na linha de plantio. A cobertura morta antecipou a colheita dos frutos em comparação ao cultivo em solo descoberto, em ambos os solos. O número de frutos por planta e a produtividade aumentaram em função quadrática com ponto de máximo de 38,6 frutos/planta -1 e 5.182,0 kg ha -¹ com 75,7% e 78,0% de cobertura morta no solo, respectivamente. A cobertura morta no solo franco-argiloso não proporcionou incremento na massa média nem alterou a qualidade dos frutos em relação aos frutos provenientes da testemunha. Termos para indexação: Passiflora edulis f. flavicarpa Degener, textura do solo, qualidade do fruto. Fruticultura orgânica.1 Agronomist, Master in Plant Production,Universidade Federal do Acre, Rio Branco-AC.