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Genetic diversity of Xylella fastidiosa in citrus producing regions in the state of Bahia, BrazilAbstract -The objective of this work was to evaluate, by SSR markers, the genetic diversity of Xylella fastidiosa in the state of Bahia, Brazil. Two of the main citrus producing regions of the state were evaluated, Litoral Norte and Recôncavo Sul. Ten samples from the state of São Paulo, Brazil, were used for comparison. The following primers were used: ASSR20, OSSR9, OSSR17, CSSR4, CSSR12, and CSSR20, of which the last four allowed the identification of 22 polymorphic loci. The citrus populations of X. fastidiosa in the state of Bahia have high genetic diversity, based on SSR markers, with distinct gene pools and geographical grouping. In Litoral Norte, the populations of the isolate show higher genetic diversity than those in the Recôncavo Sul region of Bahia.

Inadequate quantity and quality of pollen reaching the stigmas decreases the sexual reproductive output of plants, compromising yield. Still, the current extent of pollen limitation affecting yield (i.e., pollination deficits) is poorly quantified. This study is aimed at quantifying pollination deficits in kiwifruit orchards, a dioecious plant with a fruit caliber and market value largely dependent on pollination services. For that, we set up a pollination experiment and quantified services and yield provided by current pollination vectors, and under optimal pollination, over two years in a total of twenty-three orchards covering the kiwifruit production range in Portugal. We characterized nine fruit traits and used: (1) fruit weight to calculate pollination deficits and relate them with pollinator diversity and abundance, and environmental variables; and (2) production values, fruit caliber, and market values to calculate economic impact of pollination deficits. Results showed that pollination deficits were variable in time and space and were significantly and negatively correlated with pollinator abundance, while the opposite pattern was obtained for production, supporting the notion that a higher pollinator’s abundance is related to lower pollination deficits and higher yields. Understanding the factors affecting pollination deficits is crucial to depict the need for nature-based solutions promoting pollinators and to resort to management practices assisting pollination.

Arbutus unedo L. is a resilient tree with a circum-Mediterranean distribution. Besides its ecological relevance, it is vital for local economies as a fruit tree. Several microorganisms are responsible for strawberry tree diseases, leading to production constrictions. Thus, the development of alternative plant protection strategies is necessary, such as bacterial endophytes, which may increase their host’s overall fitness and productivity. As agricultural practices are a driving factor of microbiota, this paper aimed to isolate, identify and characterize endophytic bacteria from strawberry tree leaves from plants growing spontaneously in a natural environment as well as from plants growing in orchards. A total of 62 endophytes were isolated from leaves and identified as Bacillus, Paenibacillus, Pseudomonas, Sphingomonas and Staphylococcus. Although a slightly higher number of species was found in wild plants, no differences in terms of diversity indexes were found. Sixteen isolates were tested in vitro for their antagonistic effect against A. unedo mycopathogens. B. cereus was the most effective antagonist causing a growth reduction of 20% in Glomerella cingulata and 40% in Phytophthora cinnamomi and Mycosphaerella aurantia. Several endophytic isolates also exhibited plant growth-promoting potential. This study provides insights into the diversity of endophytic bacteria in A. unedo leaves and their potential role as growth promoters and pathogen antagonists.

A destinação ambientalmente adequada dos resíduos sólidos orgânicos gerados nos centros urbanos é um grande desafio, sendo a compostagem uma via eficiente para promover essa destinação. Algumas técnicas estão disponíveis para essa finalidade, mas adoção da técnica mais viável para um determinado sistema envolve avaliações multicritérios. Além disso, o perfil físico-químico desses compostos pode impactar em sua qualidade contribuindo na tomada de decisão quanto a sua destinação final. Nesse trabalho, propõe-se a análise de critérios relacionados à logística empregada e gastos associados às diferentes técnicas de compostagem empregadas no Instituto Federal de Educação, Ciência e tecnologia da Bahia, Campus de Salvador, além do perfil físico-químico dos compostos gerados. Utilizamos a vermicompostagem, compostagem convencional, além de compostagens aceleradas (com fungos e térmica com bactérias extremófilas). Foram processados cerca de 300 Kg de resíduo orgânico através dos quatro métodos em um período de seis meses, sendo o método convencional o que deteve o maior volume processado. Identificamos que os métodos são complementares em termos de eficiência quando avaliamos numa perspectiva multi-parâmetros e que a adoção de um sistema misto pode ser o mais adequado quando pensamos na compostagem não apenas como uma forma de conduzir uma destinação ambientalmente adequada dos resíduos sólidos. O uso do composto gerado pelas quatro técnicas adotadas em hortas e jardins se constitui como uma forma promissora de integrar a gestão de resíduos com a ressignificação dos espaços verdes dentro da instituição.

Arbutus unedo L. is a resilient tree with a circum-Mediterranean distribution. Besides its ecological relevance, it is vital for local economies as a fruit tree. Several microorganisms are responsible for strawberry tree diseases leading to production constrictions. Thus, the development of alternative plant protection strategies is necessary and bacteria endophytes may increase their host overall fitness and productivity. As agricultural practices are a driving factor of microbiota, this paper aimed to isolate, identify and characterize endophytic bacteria from strawberry tree leaves from plants growing spontaneously in a natural environment as well as from plants growing on orchards. 62 endophytes were isolated from leaves and identified as Bacillus, Paenibacillus, Pseudomonas, Sphingomonas and Staphylococcus. Although a slightly higher number of species was found in wild plants, no differences in terms of diversity indexes were found. Sixteen isolates were tested in vitro for their antagonistic effect against A. unedo mycopathogens. B. cereus was the most effective antagonist causing a growth reduction of 20% in Glomerella cingulata and 40% in Phytophthora cinnamomi and Mycosphaerella aurantia. Also, several endophytic isolates exhibited plant growth-promoting potential. This study provides insights into the diversity of endophytic bacteria in A. unedo leaves and their potential role as growth-promoters and pathogen antagonists.

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