Water scarcity, intensified by climate change, threatens tomato ( Solanum lycopersicum ) productivity, impacting growth, metabolism and secondary metabolite production. This study evaluated the effects of Azospirillum brasilense and Bacillus amyloliquefaciens inoculation in mitigating water stress in the Ibiza cultivar under 100%, 50% and 25% water replenishment. Severe water deficits significantly reduced morphological parameters, such as height, leaf number and dry mass. However, inoculation with B. amyloliquefaciens , particularly in combination with A. brasilense , enhanced dry mass accumulation, stem diameter and root development. Physiological analyses revealed higher electrolyte leakage and compromised membrane integrity due to water stress. Biochemical responses included increased antioxidant enzyme activity (SOD, CAT and APX) and proline accumulation, both modulated by bacterial inoculation. Interestingly, chlorophyll content increased at 25% water availability, suggesting an adaptive mechanism, while DNA content decreased. Secondary metabolites (flavonoids and phenolics) also responded to the interaction between irrigation levels and bacterial inoculation. The findings demonstrate that inoculation with A. brasilense and B. amyloliquefaciens is an effective approach to enhance tomato tolerance to water deficits by improving agronomic performance, strengthening antioxidant defences and regulating secondary metabolite production. This strategy supports the development of sustainable and adaptive agricultural practices in the face of increasing water scarcity.

INDUÇÃO IN VITRO DE BROTAÇÕES EM EXPLANTES DE PITAIA VERMELHA EM DIFERENTES CONCENTRAÇÕES DE BAP

Since the propagation of forest species is by seeds, the success of population establishment depends on the use of good quality seeds. And the use of alternative controls with essential oils for fungal control is ecologically important. The present work aimed to evaluate the influence of essential oils of Citronella (Cymbopogon winterianus), Palmarosa (Cymbopogon martini), Lemongrass (Cymbopogon citratus), Thyme (Thymus vulgaris), Eucalyptus globulus and Rosemary (Salvia rosmarinus) in reducing the incidence of fungus and physiological quality of painera—Ceiba speciosa seeds. The seeds were treated with the essential oils of Citronella, Palmarosa, Lemongrass, thyme, eucalyptus, and rosemary at a concentration of 2%. Captan fungicide (240 g/100 kg-1) was used as a control treatment. After the treatments, the seeds were evaluated by the sanity test, using the “Blotter test” filter paper method. For physiological quality, germination, first count, germination speed index, and seedling length were evaluated. The following genera of phytopathogenic fungi have been identified on Paineira seeds: Cladosporium sp., Fusarium spp., Penicillium sp., Colletotrichum sp. and Pestalotipsis sp. Treating the seeds with essential oils of Citronella, Palmarosa, Lemongrass, and Thyme controlled the fungi on the Paineira seeds. However, changes in the physiological quality of the seeds were associated with the use of the essential oils, compromising seedling vigor.

Plant tissue culture enables the controlled evaluation of plant responses under in vitro conditions, whereas biospeckle laser analysis (BSL) provides a non-invasive approach for assessing dynamic responses in living tissues. However, its application in plant tissue culture requires methodological standardization, particularly in the selection of the illuminated region. This study aimed to standardize BSL acquisition in in vitro grown A. obesum seedlings by comparing the basal, middle, and tip root regions under two contrasting culture medium conditions. Biospeckle responses were quantified using the Absolute Value of the Differences (AVD) index and graphical AVD (GAVD). A significant culture medium × root region interaction was detected for AVD. In MS medium, the basal region showed the highest AVD values, followed by the middle and tip regions, whereas no significant differences among root regions were observed in the medium without mineral salts. The mean root AVD was positively correlated with dry mass, leaf number, fresh mass, leaf length, leaf width, and root length, indicating an association with seedling performance. These findings support the basal region as a suitable candidate for standardized BSL acquisition in A. obesum under the evaluated conditions and demonstrate that root-region selection should be considered during the methodological optimization.

Com o aumento das áreas cultivadas com palma forrageira (Opuntia spp. e Nopalea spp.) no semiárido brasileiro, problemas fitossanitários têm emergido, especialmente relacionados à cochonilha-de-escama, Diaspis echinocacti. Com isso, esta pesquisa objetivou avaliar aspectos biológicos dessa cochonilha em diferentes espécies de palma forrageira. O experimento foi realizado no Laboratório de Entomologia da Universidade Federal da Paraíba. Cada cladódio foi artificialmente infestado com 25 ovos de D. Echinocacti, totalizando 75 ovos por espécie. Avaliaram-se a viabilidade de ovos, duração do período embrionário, viabilidade de ninfas, duração do período ninfal, número de adultos, período de duração da fase adulta e desenvolvimento de D. echinocacti. Os resultados demonstraram diferenças significativas entre as espécies hospedeiras, com O. tuna apresentando maior viabilidade de ovos e melhor fixação das ninfas de segundo e terceiro ínstares, bem como da fase adulta. Por outro lado, Nopalea spp. mostrou-se menos favorável ao desenvolvimento da cochonilha, indicando potencial resistência a essa praga. Além disso, quanto à duração dos diferentes estágios de desenvolvimento: o período embrionário durou 4 dias, as ninfas de primeiro, segundo e terceiro ínstar completaram seu desenvolvimento em 9, 7 e 10 dias, respectivamente. Conclui-se que O. tuna é mais suscetível à infestação por D. echinocacti, enquanto Nopalea spp. pode representar uma alternativa promissora para estratégias de manejo integrado. Estudos futuros devem explorar a identificação dos compostos ou mecanismos que conferem resistência em espécies menos suscetíveis, contribuindo para o controle sustentável da cochonilha-de-escama.