Maria Valnice de Souza Silveira

The ornamental potential of Portulaca umbraticola Kunth. stems from variation in phenotypic characteristics, enabling the selection of genotypes with desirable characters for breeding. In this context, the aim of this work was to study the ornamental potential in purslane Kunth. and to select genotypes collected across the states of Ceará, Rio Grande do Norte, and Paraíba, using the multi-characteristic genotype–ideotype distance index for simultaneous selection, comparing it with the Smith–Hazel index. The experiment was carried out in a greenhouse using a completely randomized design, comprising 22 treatments with three replications. Evaluations were performed 40 days after planting, at full flowering stage, and ten quantitative traits were measured. The dataset was then submitted to multivariate analysis to emphasize distinctions among the genotypes. The P. umbraticola genotypes were classified into three distinct groups, indicating genetic variability for the phenotypic traits assessed. Accessions AC16 and AC19 combined favorable traits associated with ornamental value, making them promising candidates for further selection and evaluation. Future studies should evaluate their combining ability and hybrid performance to support the development of superior ornamental cultivars. The genotypes AC16 and AC19 exhibited ornamental potential and are recommended for selection based on multivariate criteria to support the ongoing purslane breeding program.

Water scarcity is one of the main challenges for agricultural production in semiarid regions, compromising the development of crops such as upland cotton ( Gossypium hirsutum L.). Using starch-based biodegradable hydrogels emerge as a sustainable alternative to synthetic polymers to improve soil water retention. Our working hypothesis was that biodegradable cassava starch-based hydrogels alleviate drought damage in cotton plants associated with improved physiological coordination. Two parallels trials were conducted in greenhouse and field, in a randomized complete block design, 2 × 2 factorial scheme, combining two water regimes [well-irrigated at 90% field capacity (FC), and drought at 50% FC] and two hydrogel levels (0 and 1.0 g per plant). Drought modulated the physiological responses and significantly decreased the biometric data and biomass accumulation in both environments. The data revealed that the agronomic effectiveness of cassava starch-based hydrogel is strongly dependent on the environment. In the greenhouse, hydrogel partially mitigated drought-induced reductions in stomatal conductance and instantaneous water use efficiency without result in biomass improvement. In contrast, under field conditions, hydrogel-treated stressed plants preserved the photosynthetic pigments, a response associated with enhanced water use efficiency and shoot dry mass, resulting in an increased relative drought tolerance. In conclusion, hydrogel polymers alleviate drought damages on cotton performance under field conditions, highlighting potential of biopolymer incorporation into sustainable water management practices.

Cowpea is a crop of great economic and nutritional importance, used for human and animal consumption, particularly in semi-arid regions. Its growth and development depend on adequate conditions for the expansion of the root system and the establishment. Therefore, the objective of this study was to determine the effect of pot size on the shoot and root development of cowpea. The experiment was conducted in a greenhouse at the Department of Plant Science, Federal University of Ceará, in Fortaleza, Ceará, Brazil. Seeds of the Setentão variety were used in a completely randomized experimental design with five replications. The plants were grown in pots with volumes of 5, 11, 18, and 25 dm³, and shoot and root system traits were evaluated, including stem, leaves, pods, dry seeds, and roots. The data were subjected to analysis of variance and mean comparison tests, as well as correlation and principal component analyses. Pot size significantly influenced plant development and the most of the evaluated traits showed strong positive correlations, indicating a close interdependence between shoot and root system variables. Principal component analysis explained 65.7% of the total observed variation. Among the evaluated pot volumes, the 18 dm³ pot showed the best overall performance, considering vegetative, productive, and root traits, and is therefore recommended for cowpea studies and production under pot conditions.

Enzymatic browning represents one of the main challenges in the postharvest conservation of minimally processed sweet potatoes, as it affects appearance and reduces consumer acceptance. This study aimed to evaluate the effectiveness of different packaging types and alternative enzymatic inactivation techniques using natural antioxidants (citric acid and apple cider vinegar) and thermal treatment applied to off-grade sweet potato roots. Samples were stored in two types of packaging (expanded polystyrene trays wrapped with PVC film and sealed textured plastic bags) under controlled conditions of 18 °C for up to 12 days. Parameters such as pH, soluble solids, and enzymatic browning were analyzed. The results indicated that treatment with citric acid combined with textured packaging was the most effective in preserving physicochemical quality and reducing enzymatic browning during storage. Although thermal treatment promoted an increase in soluble sugar content, it resulted in greater enzymatic browning, especially when combined with trays covered with PVC film. It is concluded that the use of natural antioxidants along with appropriate packaging constitutes a viable strategy for adding value to off-grade sweet potatoes, extending shelf life, and reducing postharvest losses. Keywords: Ipomoea batatas; minimal processing; enzymatic oxidation; postharvest preservation.

In the flower and ornamental plant sector, species of genus Anthurium stand out, particularly Anthurium plowmanii, known for its lush, wavy, bright green leaves, which create an eye-catching and harmonious display, making it ideal for the foliage market. The species is mainly propagated from seeds, a lengthy process, requiring time for the seedling to reach the commercial stage, and resulting in non-uniform plants that differ from the parents. In this respect, tissue culture is seen as an efficient alternative in the large-scale production of uniform plantlets of high genetic and phytosanitary quality. The aim of this study was to evaluate the in-vitro propagation of A. plowmanii from nodal segments in Pierik culture medium with different concentrations of cytokinin. The experimental design was completely randomised, and included six BAP concentrations (0, 1.11, 2.22, 3.33, 4.44 and 5.55 µM) in five replications, each replication comprising 10 test tubes containing one nodal segment. After 60 days of in-vitro culture, the nodal segment explants were evaluated for the number of shoots and roots, height, fresh and dry matter, number of leaves and length of the longest root. The results show that for shoot formation in A. plowmanii, BAP must be added to the culture medium at a concentration of 3.33 µM. Furthermore, increasing the BAP concentration resulted in a greater number of leaves and an increase in the fresh and dry matter of the explant.

Using reaction norm components instead of traditional phenotypic data in genetic association studies (GWAS) may allow the identification of genomic regions that are more influenced by environmental variables in terms of tolerance and responsiveness to water stress. To test this hypothesis, we used a public genetic diversity panel of tropical maize inbred lines, evaluated in eight environments, four in well‐watered (WW) and four in water stress (WS) conditions. Most SNPs explained at least 40% of the genetic variability, and some reached 67%. The identified genes and genomic regions revealed physiological responses and direct or indirect molecular mechanisms related to water deficit tolerance and responsiveness. This information will enable more assertive selections and subsidize breeding programs aimed at obtaining cultivars for water deficit conditions while reducing the costs of the evaluation processes of reaction standards.

A avaliação multitemporal do uso e cobertura da terra está relacionada com a forma pela qual o espaço está sendo usado pelo homem, ou preenchido pela cobertura natural ao longo dos anos. Esta observação pode ser feita via o sensoriamento remoto, que possibilita identificar os efeitos do uso desordenado dos recursos naturais, podendo ser utilizada como subsídio para tomadas de decisões relacionadas a conservação e preservação do meio ambiente. Neste contexto, este trabalho teve como objetivo analisar o uso e cobertura da terra e o avanço da agropecuária no estado da Paraíba. As informações georreferenciadas relativas à cobertura e uso do solo, foram obtidas a partir da coleção 7.0 da plataforma aberta do Projeto MapBiomas. Para realização dos cálculos e elaboração dos gráficos, os dados foram agrupados em classes, e posteriormente elaborados tabelas e gráficos para visualização dos resultados. O estado da Paraíba apresenta uma cobertura e uso da terra de forma diversa, composta por floresta, formação vegetal não floresta, agropecuária, área não vegetada e corpo d’água. Existe oscilação na cobertura vegetal no estado da Paraíba ao longo dos 35 anos avaliados, com redução da área de floresta e corpo d’água, e avanço na atividade agropecuária.

The root system is an organ that indicates signs of stress when a plant is subjected to water‐deficit conditions. However, its assessment is challenging. An alternative has been to obtain variables through image processing. In this way, it allows the rapid evaluation of genetic diversity panels. It contributes to identifying genomic regions or genes associated with the expression of the root system under water‐deficit conditions. Hence, a public diversity panel of 360 inbred lines of maize was evaluated under well‐watered (WW) and water stress (WS) conditions. Roots were phenotyped through image‐based processing. Then, genome‐wide association studies were conducted in WW and WS for each trait, using the Fixed and random model Circulating Probability Unification method. We found 23 genes or genomic regions with significant associations, of which eleven are exclusive to the WW condition, seven to the WS condition, and four are simultaneously associated with both WW and WS. All genomic regions related to the root system in the WS condition are associated with physiological mechanisms and molecular responses related to tolerance to water‐deficit conditions that can be explored in subsequent studies and by breeding programs to obtain varieties that are more tolerant and water efficient to this condition.

Dracaena reflexa Lam. possui potencial ornamental e medicinal e sua propagação ocorre, preferencialmente, por via assexuada. Os indutores naturais podem incrementar o processo de enraizamento de estacas. Objetivou-se avaliar a eficiência de indutores naturais no enraizamento e desenvolvimento de estacas de D. reflexa, com presença ou ausência de folhas. O experimento foi realizado em delineamento inteiramente casualizado, com esquema fatorial 3x2, (água de coco + polpa de banana; extrato de sementes germinadas de feijão ou água de arroz + polpa de batata-doce) e (presença ou ausência de folhas nas estacas), com quatro repetições. A água de coco + polpa de banana proporcionou aumento do número de folhas, número, comprimento e massa seca de raízes; e da massa seca de parte aérea, quando aplicada em estacas com presença de folhas. A aplicação do indutor natural água de coco + polpa de banana proporciona maior enraizamento e desenvolvimento de estacas de Dracaena reflexa.