ABSTRACT The search for bioherbicides has been encouraged, and plants used in food or with bioactivity have been studied. Therefore, this article aimed to investigate the bioherbicidal potential of essential oils from Psidium cauliflorum and P. acidum through a plant toxicity bioassay using Lactuca sativa and Sorghum bicolor. The seeds were treated with essential oils of both species, along with control groups treated with distilled water, dichloromethane, and glyphosate. Germination percentage (GP), germination speed index (GSI), root growth (RG), shoot length (SL), mitotic index (MI), chromosomal alterations (CA), and nuclear alterations (NA) were evaluated. The major compound of the essential oil of P. cauliflorum was α-pinene, and of P. acidum were trans-caryophyllene, β-elemene, germacrene A, and α-copaene. The essential oils from both species exhibited phytotoxic effects. P. acidum oil inhibited sorghum RG and lettuce SL, while P. cauliflorum oil reduced GP, GSI, RG, and SL in both plants, indicating higher phytotoxicity than P. acidum and non-selective behavior. Cytotoxic investigations showed that both oils inhibited the MI. CA analysis revealed that P. cauliflorum oil exhibited aneugenic and clastogenic action mechanisms. The results demonstrate the bioherbicidal potential of P. cauliflorum essential oil, in addition to being non-selective and displaying a similar inhibition rate to glyphosate.

Resumo As características anatômicas foliares são amplamente utilizadas para melhor compreender a taxonomia entre as angiospermas. No entanto, tais informação são escassas para a família Myrtaceae. Com o objetivo de preencher esta lacuna de conhecimento, estudamos a anatomia foliar de dez espécies do gênero Psidium: P. cattleyanum, P. cauliflorum, P. corynanthum, P. guajava, P. guineense, P. macahense, P. myrtoides, P. oligospermum, P. ovale e P. sartorianum. A epiderme unisseriada, os estômatos paracíticos, as cavidades secretoras e a hipoderme adaxial são comuns entre as espécies estudadas e são características típicas de Myrtaceae. A presença de três ou mais camadas de parênquima paliçádico e a ausência de esclerênquima são caracteres diagnósticos de P. guajava. A epiderme abaxial de Psidium cattleyanum e P. macahense possuem paredes curvas. Psidium corynanthum e P. macahense são as únicas espécies com paredes anticlinais sinuosas em ambos os lados da epiderme, sendo que todas as outras espécies têm paredes retas ou curvas. Os feixes vasculares bicolaterais abertos estão presentes em todas as espécies estudadas, exceto em P. guineense. Com exceção de P. cauliflorum, todas as espécies estudadas possuem drusas. A ausência de colênquima na face adaxial é exclusiva de P. ovale. A anatomia foliar de P. macahense, P. corynanthum, P. oligospermum e P. ovale é descrita pela primeira vez neste trabalho. angiospermas entanto Myrtaceae conhecimento P cauliflorum guajava guineense myrtoides sartorianum unisseriada paracíticos curvas drusas trabalho

Abstract Leaf anatomical features are widely used to better understand angiosperm taxonomy. However, such information is scarce for the family Myrtaceae. Aiming to fill this knowledge gap, we studied anatomical and micromorphological leaf characters of ten species of Psidium: P. cattleyanum, P. cauliflorum, P. corynanthum, P. guajava, P. guineense, P. macahense, P. myrtoides, P. oligospermum, P. ovale and P. sartorianum. Uniseriate epidermis, paracytic stomata, secretory cavities, and adaxial hypodermis are common among the studied species and are typical characteristics of Myrtaceae. The presence of three or more layers of palisade parenchyma and the absence of sclerenchyma are diagnostic characters of P. guajava. The abaxial epidermis of Psidium cattleyanum and P. macahense possess curved walls. Psidium corynanthum and P. macahense are the only species with sinuous anticlinal walls on both sides of the epidermis, with all other species having straight or curved walls. Open bicollateral vascular bundles are present in all the studied species except P. guineense. With the exception of P. cauliflorum, all the studied species possess druses. The absence of collenchyma in the adaxial face is exclusive to P. ovale. The leaf anatomy of P. macahense, P. corynanthum, P. oligospermum and P. ovale are described for the first time here. taxonomy However Myrtaceae gap P cauliflorum guajava guineense myrtoides sartorianum stomata cavities druses here

Abstract We investigated whether essential oil and aqueous and ethanolic extracts from M. vittoriana leaves have phytotoxic effects on the germination and initial development, and cytogenotoxic effects on the cell cycle, of model plants. The essential oil and extracts of M. vittoriana were characterized and used as treatments in phytotoxicity and cytotoxicity tests. The results indicated a reduction in germinative parameters and plant growth, with the higher concentrations of extracts and essential oil having the most evident effects. The cell cycle was also affected with a reduction of the mitotic index and the presence of chromosomal and nuclear alterations. All treatments showed clastogenic and aneugenic modes of action. The results can be associated with the synergistic effects of metabolites found in the extracts and essential oil, mainly the presence of the sesquiterpene germacrene D in the essential oil and of catechins, saponins, and tannins in the extracts. These substances inhibit plant germination and growth, confirming the phytotoxic effects of M. vittoriana in plant models, which should now be tested under field conditions.

Resumo Com mais de 46.000 espécies de plantas, o Brasil tem uma das maiores diversidades biológicas do mundo. Essa imensa riqueza ainda é pouco conhecida e sua utilização como alimento tem sido negligenciada. O uso da biodiversidade local na alimentação contribui para a ampliação das fontes de nutrientes disponíveis à população e para a promoção da soberania e segurança alimentar. O presente estudo analisou o conhecimento e o uso de plantas alimentícias não convencionais (PANC) na comunidade rural de São José da Figueira, Durandé, Minas Gerais, Brasil. A pesquisa foi conduzida utilizando a técnica “bola de neve” com entrevistas semi-estruturadas. As famílias botânicas foram classificadas e a frequência relativa de citação das espécies (Fr) foi avaliada. Foram registradas 56 espécies de PANC, distribuídas em 29 famílias botânicas. As famílias Asteraceae e Lamiaceae se destacaram pela riqueza de espécies, contribuindo com 9 e 6 espécies, respectivamente. Sonchus oleraceus e Xanthosoma sagittifolium obtiveram as maiores frequências relativas de citação (32,1). A maior parte das plantas citadas como alimentícias é nativa (38,2%). Os resultados encontrados demonstram o grande conhecimento da comunidade acerca da diversidade local e a importância dessas espécies na alimentação da comunidade.

Abstract With more than 46.000 species of plants, Brazil has one of the largest biological diversity in the world. This biodiversity is still little known and its use as food has been neglected. The use of local biodiversity in diet contributes to the expansion of the sources of nutrients available to the population and to the promotion of food sovereignty and security. The present study analyzed the knowledge and the use of unconventional food plants (UFP) in the rural community of São José da Figueira, Durandé, Minas Gerais, Brazil. The research was conducted using the Snowball Sampling with semi-structured interviews. The relative frequency of species citation (Fr) was evaluated. There were 56 species of UFP distributed in 29 botanical families. Asteraceae and Lamiaceae were distinguished by the richness of food species, contributing with 9 and 6 species, respectively. Sonchus oleraceus (Asteraceae) and Xanthosoma sagittifolium (Araceae) had the highest relative frequencies of citation (32.1). Most of the plants cited are native (38.2%). The results show the great knowledge of the community about the local diversity, and the importance of these species in the feeding of families. The results show the great knowledge of the community about the local diversity, and the importance of these species in the community alimentation.