The present investigation aimed to develop inclusion complexes (ICs) from Psidium gaudichaudianum (GAU) essential oil (EO) and its major compound β-caryophyllene (β-CAR), and to evaluate their herbicidal (against Lolium multiflorum and Bidens pilosa) and cytogenotoxic (on Lactuca sativa) activities. The ICs were obtained using 2-hydroxypropyl-β-cyclodextrin (HPβCD) and they were prepared to avoid or reduce the volatility and degradation of GAU EO and β-CAR. The ICs obtained showed a complexation efficiency of 91.5 and 83.9% for GAU EO and β-CAR, respectively. The IC of GAU EO at a concentration of 3000 µg mL−1 displayed a significant effect against weed species B. pilosa and L. multiflorum. However, the β-CAR IC at a concentration of 3000 µg mL−1 was effective only on L. multiflorum. In addition, the cytogenotoxic activity evaluation revealed that there was a reduction in the mitotic index and an increase in chromosomal abnormalities. The produced ICs were able to protect the EO and β-CAR from volatility and degradation, with a high thermal stability, and they also enabled the solubilization of the EO and β-CAR in water without the addition of an organic solvent. Therefore, it is possible to indicate the obtained products as potential candidates for commercial exploration since the ICs allow the complexed EO to exhibit a more stable chemical constitution than pure EO under storage conditions.
The correct identification of Coffea canephora genotypes into the botanical groups Conilon, Robusta and their hybrids is fundamental for breeding strategies aimed at developing and selecting commercial clones; however, genotype discrimination is challenging when based only on morphological attributes. A total of 121 individuals were evaluated from the Incaper Active Germplasm Bank (BAG): 52 Conilon, 33 Robusta, and 36 hybrids (morphological intermediates showing traits of both groups). DArTseq™ SNPs were filtered, and 1,551 markers were used in the analyses. Cluster analyses revealed three genetic groups: one Robusta (G1) and two Conilon (G2 and G3). AMOVA indicated that 78.49% of the variation occurred among groups and 21.51% within groups. Differentiation was greatest between G1 and G3 (Fst = 0.77), followed by G1 and G2 (Fst = 0.46), whereas G2 and G3 showed lower differentiation (Fst = 0.31). G2 showed high genetic diversity and greater genotypic variability, with three SNP-defined genotypes, suggesting the presence of genetic hybrids. Ten SNPs, located on nine chromosomes and outside genic regions, were validated to discriminate the botanical groups, providing a molecular fingerprinting tool for the characterization of C. canephora germplasm in Brazil.
1 January 2019 in Revista Colombiana de Ciencias Hortícolas
The tomato root-knot nematode is one of the main phytosanitary problems in crops. Chemical control is the phytosanitary method most used by farmers, and the study of alternative management of phytonematodes is crucial. The objective of this study was to evaluate the effect of silicon dioxide (SiO2) on the initial development of tomato plants, as well as to determine the best dose of SiO2 for inducing resistance to parasitism by M. incognita. This experiment was set up under a completely randomized design with ten treatments and five replicates in a 5×2 factorial arrangement consisting of five concentrations of SiO2 (0, 0.15, 0.3, 0.45 and 0.6 g dm-³ of soil) with the presence and absence of M. incognita, under greenhouse conditions. The following variables were evaluated: plant height; number of leaves; fresh and dry weight of shoot; percentage of shoot dry matter; root fresh weight; number of galls; final population of nematodes; and population per gram of root. The M. incognita infection affected plant height, number of leaves and shoot fresh weight, while the application of SiO2 negatively affected the formation of galls in the roots of the inoculated plants and the population per gram of root, reducing the final population of nematodes in the root system. SiO2 also provided greater development in the tomato plants, with a significant effect on plant height. The ideal dose was 0.34 g dm-3 of SiO2.
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.