Plants have been used for centuries as therapeutic resources for various pathological conditions and are occasionally considered as the only resource available to some communities. However, knowledge on the potential of traditional medicinal plants have been lost over the years. Strategies that can guarantee the prospection of popular knowledge regarding medicinal plants to stimulate the spread of information between generations are therefore of enormous value. Thus, the present study aimed to investigate the use and knowledge on medicinal plants of students from a public school in Vila Velha (Brazil) and their associated community, including parents. In this urban locality, data were obtained by the application of a semi-structured questionnaire to 206 people from the school community. Although homegrown cultivation seems to be an uncommon practice in urban contexts, the use of medicinal plants by the sampled population was significant (80%), as well as the interviewees’ confidence on its therapeutic action (90%). It is worth mentioning that more than 70% of the respondents presented their parents and/or grandparents as their main source of information, highlighting the importance of popular knowledge valorization.

ABSTRACT Mango wilt, caused by the fungus Ceratocystis fimbriata, is an important disease affecting mango production. In view of the beneficial effects of potassium (K) in other profitable crops and the lack of information about the effect of macronutrients on mango wilt development, the present study aimed to evaluate how mango plants supplied with K respond physiologically when infected by C. fimbriata. Mango plants (» 3 years old) from cultivar Ubá were grown in plastic pots containing 58 mg of K·dm−3 (original K level based on the chemical analysis of the substrate) or in plastic pots with substrate amended with a solution of 0.5 M potassium chloride (KCl) to achieve the rate of 240 mg K·dm−3. Disease symptoms were more pronounced in inoculated plants grown at the lower K level. Substantial declines in stomatal conductance, in line with decreases in the internal-to-ambient CO2 concentration ratio and the absence of detectable changes in the chlorophyll a fluorescence parameters, suggest that the decrease in the net carbon assimilation rate is due, at least initially, to stomatal limitations. High concentrations of K and manganese were found in the stem tissues of inoculated plants and supplied with the highest K rate, most likely due to the involvement of these tissues in the local development of defense mechanisms. The results of this study suggest that the supply of K favored the physiological performance of mango plants and their resistance against C. fimbriata infection.

ABSTRACT Mango wilt, caused by Ceratocystis fimbriata, is one of the most important diseases affecting mango yields in Brazil. Information regarding the biochemical mechanisms involved in mango resistance against C. fimbriata is absent in the literature. Thus, the present study determined and quantified alkaloids and phenolics in the stem tissue of mango plants from Palmer (susceptible) and Ubá (resistant) cultivars. Furthermore, it was examined the effect of these secondary metabolites against C. fimbriata growth in vitro. The high-performance liquid chromatography revealed that the concentration of two alkaloids (theobromine and 7-methylxanthine) and six phenolic compounds (caffeic acid, p-coumaric acid, gallic acid, protocatechuic acid, catechin and epicatechin) in the inoculated plants from cv. Ubá was higher in comparison with inoculated plants from cv. Palmer. The concentration of the secondary metabolites was higher in the non-inoculated plants from cv. Palmer than in the inoculated ones, while the opposite was observed for plants of cv. Ubá. Peaks in the concentrations of secondary metabolites in the inoculated plants from both cultivars occurred at 7 and 14 days after inoculation. The different concentrations (10 to 30 mg∙mL−1) of secondary metabolites added to the Petri dishes greatly inhibited C. fimbriata growth over time. These results suggest that secondary metabolites played an important role in the resistance of mango plants against C. fimbriata infection.

ABSTRACT Caused by the vascular fungus Ceratocystis fimbriata, mango wilt is considered to be one of the most serious threats in mango-producing regions worldwide. However, changes in leaf gas exchange level and the mechanisms underlying host responses to this fungal infection remain poorly described. This study aimed to evaluate potential changes in the leaf gas exchange of different mango cultivars (Ubá, Espada, Haden and Tommy Atkins) in response to two Brazilian isolates of C. fimbriata (CEBS15 and MSAK16) to non-invasively assess cultivar variability in relation to the basal level of resistance to mango wilt. Both isolates, regardless of the cultivar, caused reductions in stomatal conductance and, thus, a reduction in CO2 assimilation via diffusive limitations. Taking into account the full length of the internal lesion and the radial colonization of the stem tissues, both isolates showed equivalent aggressiveness when inoculated into the Haden and Tommy Atkins cultivars. Conversely, when compared to the CEBS15 isolate of C. fimbriata, the MSAK16 isolate was more aggressive in cv. Espada and less aggressive in cv. Ubá.

RESUMO Apesar de a manga ser uma das frutas tropicais de maior interesse no comércio mundial, a literatura sobre os seus porta-enxertos (características e utilização) é escassa. Este estudo teve como objetivo caracterizar as mangueiras da cv. Imbu, amplamente utilizada como porta-enxerto na região da Zona da Mata de Minas Gerais (MG), Brasil. E, embora frutos dessa cultivar não apresentem características comerciais desejáveis, este estudo permitiu caracterizar parte da morfologia da planta e preencher uma lacuna na literatura, fornecendo subsídios para futuras investigações. Para tal, folhas completamente expandidas da porção mediana de ramos expostos à luz solar e frutos plenamente desenvolvidos foram coletados de plantas da cv. 'Imbu' (˜ 4 anos de idade) da coleção da Universidade Federal de Viçosa, localizada no município de Viçosa - MG. Os descritores foram: (i) divisão lâmina de folha; (ii) a composição da folha; (iii) comprimento do pecíolo em relação à lâmina de folha; (iv) filotaxia, (v) a posição das folhas em relação à inserção do ramo; (vi) a forma de folha; (vii) ângulos do vértice da folha e de base; (viii) categoria margem da folha; (ix) venação; (x) comprimento da folha e espessura; (xi) Relação espessura / comprimento da folha; (xii) textura da folha; (xiii) fragrância da folha; (xix) cor da folha. As folhas foram descritas como lanceoladas, com margens inteiras e ângulos afilados na base e ápice da lâmina de folha. A intensidade da cor verde da lâmina foliar foi considerada intermediária e a coloração da superfície abaxial mostrou menos intensa do que a observada no lado superior. Os frutos foram processados e separados em casca, polpa e sementes, a fim de avaliar a cor da polpa, o peso fresco e percentagem de sementes, casca e polpa. Foi determinado o teor de sólidos solúveis, concentração de amido, coloração da casca e da polpa, a cerosidade, a percentagem de casca, de polpa e de semente e a firmeza da polpa. O número médio de plântulas germinadas por semente foi estimado para 230 sementes semeadas.

ABSTRACT Although mango is one of the tropical fruits of greater interest in the world trade, literature concerning their rootstocks (characteristics and utilization) is scarce. This study aimed to characterize mango plants from cv. Imbú, widely used as rootstock in the Zona da Mata region, State of Minas Gerais (MG), Brazil. Though fruits of this cultivar do not present desirable commercial characteristics, this study allowed us to characterize part of plant morphology and fill a gap in the literature, providing subsidies for future investigations. For such, 'Imbú' plants (˜ 4-years old) from the collection of the Universidade Federal de Viçosa, located in Viçosa -MG were evaluated. The descriptors were: (i) leaf blade division;(ii) leaf composition; (iii) petiole length in relation to leaf blade; (iv) phyllotaxis, (v) leaf position in relation to the branch insertion; (vi) leaf shape; (vii) leaf apex and base angles; (viii) leaf margin category; (ix) venation; (x) leaf length and thickness; (xi) leaf length/thickness ratio; (xii) leaf texture; (xiii) leaf fragrance; (xix) leaf color. The leaves were depicted as lanceolate, with entire margins and sharp angles at the base and apex of the leaf blade. The intensity of the green color of the leaf blade was considered intermediate and the abaxial surface staining showed less intense than that observed in the upper side. The fruits were processed and separated into peel, pulp and seeds in order to evaluate the flesh color, fresh weight and percentage of seeds, peel and pulp. It was determined the soluble solids content, starch concentration, the peel and the pulp color, the cerosity, the percentage evaluation of peel, pulp and seed and the pulp firmness. The average number of germinated seedlings per seed was estimated for 230 sown seeds.

Brown spot (BS), caused by the fungus Bipolaris oryzae, is one of the most important diseases contracted by rice. We investigated the effect of magnesium (Mg) on the development of BS, caused by Bipolaris oryzae, and the effects of disease development on the photosynthetic performance of rice (Oryza sativa L.) plants (cv. Metica-1) grown in nutrient solutions containing 0.25 or 4.0 mM of Mg. Assessments of BS severity, leaf Mg and pigment concentrations (total chlorophylls and carotenoids), were carried out at 120 h after inoculation, in addition to gas exchange parameters,. Higher leaf concentration of Mg was observed in plants supplied with 4.0 mM Mg than in those supplied with 0.25 mM. The increase in leaf Mg was accompanied by a decrease in BS severity, higher concentration of total chlorophyll and better photosynthetic performance. Plants supplied with 4.0 mM Mg had higher average values for carbon assimilation, stomatal conductance and internal leaf CO2 concentration when compared with plants supplied with 0.25 mM Mg. Conversely, the concentration of carotenoids was lower in plants supplied with the higher Mg rate. These results suggest that Mg suppresses disease severity and preserves photosynthetic performance by allowing for better stomatal conductance and, consequently, greater availability of CO2 at the carboxylation sites.