Cereus Jamacaru DC Research Articles

Cereus jamacaru DC. (mandacaru) fruit as a source of lactic acid bacteria with in vitro probiotic-related characteristics and its protective effects on Pediococcus pentosaceus during lyophilization and refrigeration storage

This study isolated and identified autochthonous lactic acid bacteria (LAB) from mandacaru fruit and evaluated their potential probiotic and technological aptitudes in vitro, as well as the protective effects of freeze-dried mandacaru fruit on the most promising LAB isolate during lyophilization and refrigeration storage. Initially, 212 colonies were isolated from mandacaru fruit, and 34 were preliminarily identified as LAB. Thirteen isolates identified by 16S-rRNA sequencing as Pediococcus pentosaceus were negative for DNase, gelatinase, hemolytic, and biogenic amine production. The selected isolates showed proteolytic activity, diacetyl and exopolysaccharide production, and good tolerance to different NaCl concentrations while having low cellular hydrophobicity and antagonistic activity against pathogens. The survival of isolates sharply decreased after 3 h of exposure to pH 2 and had a good tolerance to 1 % bile salt. A principal component analysis selected P. pentosaceus 57 as the most promising isolate based on the examined technological and probiotic-related physiological properties. This isolate was lyophilized with mandacaru fruit and stored under refrigeration for 90 days. P. pentosaceus 57 lyophilized with mandacaru fruit had high viable cell counts (9.69 ± 0.03 log CFU/mL) and >50 % of physiologically active cells at 90 days of refrigeration storage. The results indicate that mandacaru fruit is a source of P. pentosaceus with aptitudes to be explored as potential probiotic and technological characteristics of interest for the food industry, besides being a good candidate for use in lyophilization processes and refrigeration storage of LAB due to its cryoprotective effects.

Germination responses of the invasive hedge cactus (Cereus uruguayanus) to environmental factors

AbstractHedge cactus (Cereus uruguayanus R. Kiesling; syn.: Cereus hildmannianus K. Schum.) is a columnar cactus that was introduced to Australia as an ornamental plant and has since become invasive in subhumid regions of Queensland and New South Wales. Compared with its congener, queen of the night (Cereus jamacaru DC.), which is currently invasive in both eastern and southern Africa, information on seed biology of C. uruguayanus is lacking. Experiments were conducted to study the effects of alternating day/night temperature, salt stress, water stress, and burial depth on germination and seedling emergence of four seed accessions of C. uruguayanus. Seeds were also subjected to a controlled aging test (CAT) to obtain an estimate of potential persistence under field conditions. The optimum temperature regime for germination of all accessions was 30/20 C. Germination decreased with an increase in sodium chloride (NaCl) concentration, but germination of all accessions (range 26% to 81%) occurred at 160 mM NaCl, indicating very high salt tolerance. Seed germination gradually decreased with an increase in water stress, but germination in all accessions (range 19% to 47%) occurred at −0.8 MPa. Seed viability and dormancy status were unaffected by exposure to salt level (320 mM NaCl) and water (−1.6 MPa) stress under which germination did not occur. Germination responses to all three factors were generally similar to those documented for C. jamacaru. The emergence of C. uruguayanus decreased with an increase in seed burial depth. The highest emergence (43%) was recorded for surface-sown seeds, and emergence was reduced to 0 at a burial depth of 2 cm. CAT results for two seed accessions indicated that seeds of C. uruguayanus are likely to demonstrate extended (>3 yr) persistence under field conditions, a prediction that is supported by evidence that germination of its small (2-mm) seeds is markedly reduced by burial.

Mapping ethnobotanical aspects of the iconic Mandacaru cactus, Cereus jamacaru DC. in Brazil: a scientometric review.

Cereus jamacaru DC. occurs in the central-eastern region of Brazil and is among the best-known cacti in the country. Its phytochemical properties and fruits hold great significance to the local communities. We examined published ethnobotanical studies regarding C. jamacaru (mandacaru) undertaken between 2000 to 2024, to better understand its traditional uses and relationships with human communities in Brazil. The literature review was carried out by consulting the databases Google Scholar (166 articles), Scopus (1 article) and Web of Science (2 articles), and followed the PRISMA 2020 protocol. A total of 169 articles were identified, of which 45 were deemed relevant. The most frequent uses of C. jamacaru include medicinal (cited in 32 articles), human consumption as a non-conventional food (22), and forage (18). C. jamacaru is often cited to treat health conditions such as kidney problems, flu and inflammations, but it's also used for construction and crafts. Our results highlight the diverse and vital uses of C. jamacaru for human communities. Furthermore, we demonstrate the pattern of knowledge production regarding the ethnobotany of this species and the challenges for its conservation and the preservation of associated traditional knowledge.

Physiological and biochemical alterations driven by light quality during germination and initial growth of the mandacaru cactus (Cereus jamacaru DC.)

Physiological and biochemical alterations driven by light quality during germination and initial growth of the mandacaru cactus (Cereus jamacaru DC.)

Management practices of Cereus jamacaru DC in the Caatinga dry forest differentially affect its reproductive phenology, fruit set and nectar availability

The management of plants and landscapes can affect the reproductive cycle of species through changes in morphology, temporal distribution of resources, and productivity, with ecological implications. In this study, we investigated the influence of management practices on the reproductive phenology and nectar availability of Cereus jamacaru DC, a columnar cactus native to Brazil managed by local people in the Caatinga dry forest. Our results reveal that the traditional management practices alter the quantitative and spatiotemporal distribution of resources (flowers, fruits, and nectar) of individuals of C. jamacaru in the studied Caatinga. All populations exhibited annual patterns of flowering and fruiting. However, individuals of the ex situ managed population showed a distinct temporal distribution pattern of flowering, with flower buds and flowers more regularly distributed throughout the reproductive period, compared to individuals of the in situ and unmanaged populations. Management practices differentially affected the production of flower buds, flowers, and fruits with a positive effect on fruit set in the in situ managed population. In addition, individuals of managed populations presented anticipation in the average date of the emission peaks of flower buds and ripe fruits. Individuals from the in situ managed population had available a greater volume of nectar with a higher sugar concentration per flower (twice as high) compared to the ex situ managed population and unmanaged population. The management practices seem to provide advantageous conditions for individuals of C. jamacaru since they allow higher availability of resources (flowers, nectar, and fruits) for a longer period in the Caatinga dry forest. Thus, management practices can prolong the temporal distribution of flowers and fruits, providing more resources for specialized pollinators (Sphingids) and dispersers (birds, reptiles), which are groups vulnerable to anthropic disturbances and climate changes in the Caatinga dry forest. These practices ultimately contribute to the maintenance of key ecological interactions of other species dependent on these vectors, benefiting the whole plant and animal community in the Caatinga dry forest.

Irrigation level and substrate type on the acclimatization and development of mandacaru (Cereus jamacaru DC.): an emblematic cactus from Brazilian semiarid region

Mandacaru is a cactus with great socioeconomic potential, but lack of information about its cultivation hinders its domestication. Here, we aimed to evaluate the acclimatization and vegetative development of mandacaru under different substrates and irrigation levels. For this, seeds inoculated in vitro were grown for 120 days, being transplanted to pots containing four types of substrate (S1—caatinga soil + gravel; S2—washed sand + organic matter + soil + charcoal; S3—washed sand + cattle manure + soil + sand; S4—commercial organic substrate). Pots were irrigated with 100% of the field capacity (FC) once-a-week, or with 50% FC twice-a-week, and kept in a greenhouse for six months. The experimental design was completely randomized, in a 4 × 2 factorial scheme, with six replications. Plant height and diameter, axial and radial growth rate, fresh and dry mass of stem and root, water content, and photosynthetic pigments were determined. Growth was affected mainly by the substrate, with S4 resulting in higher growth and pigment content, while S1 was impaired and S2 and S3 resulted in intermediate growth. The use of S4 and 100% FC once per week was the best condition for mandacaru.

Biosorption process using Cereus jamacaru DC, Cactaceae for Pb2+ removal from aqueous systems

ABSTRACT Lead is a highly toxic metal associated with many human health diseases that can be caused by several environmental changes. Innovative sustainable solutions for water remediation have been recently encouraged by using renewable, low-cost and earth-abundant biomass materials to ensure public health conditions. In this article, Cereus jamacaru DC (popularly known as Mandacaru) was investigated as a biosorbent in the Pb2+ removal from aqueous solution using a two-level factorial design. The analysis of variance suggested a significant and predictive model (R 2 = 0.9037). The maximum efficacy of Pb2+ removal in the experimental design was 97.26%, being the optimized conditions: pH 5.0, contact time 4 h without adding NaCl. The Mandacaru was divided into three types according to the plant structure and this parameter did not present a significant interference in the biosorption process. This result corroborates with slight differences in the total soluble proteins, carbohydrates and phenolic compounds found in the Mandacaru types investigated. FT-IR analysis revealed the presence of O–H, C–O and C = O groups that were responsible for the ion biosorption process. The optimized procedure was capable to remove 97.28% of the Pb2+ added in the Taborda river water sample. The kinetic adsorption results show the pseudo-second-order model, suggesting chemisorption process. Thus the treated water sample can be considered in accordance with technical standards issued by CONAMA Resolution Num. 430/2011 and Ordinance GM/MS Num.888/2021 of WHO. In this way, the Mandacaru proved to be an efficient, fast and easy-to-apply bioadsorbent in Pb2+ removal and has great environmental application potential.

Mandacaru cactus as a source of nanofibrillated cellulose for nanopaper production

In this work, nanofibrillated cellulose (NFC) was extracted from cactus Cereus jamacaru DC. (mandacaru) for nanopaper production. The technique adopted includes alkaline treatment, bleaching, and grinding treatment. The NFC was characterized according to its properties and scored based on a quality index. Particle homogeneity, turbidity, and microstructure of the suspensions were evaluated. Correspondingly, the optical and physical-mechanical properties of the nanopapers were investigated. The chemical constituents of the material were analyzed. The sedimentation test and the zeta potential analyzed the stability of the NFC suspension. The morphological investigation was performed using environmental scanning electron microscopy (ESEM) and transmission electron microscopy (TEM). X-ray diffraction (XRD) analysis revealed that Mandacaru NFC has high crystallinity. Thermogravimetric analysis (TGA) and mechanical analysis were also used and revealed good thermal stability and good mechanical properties of the material. Therefore, the application of mandacaru is interesting in sectors such as packaging and electronic device development, as well as in composite materials. Given its score of 72 points on a quality index, this material was presented as an attractive, facile, and innovative source for obtaining NFC.

Pressurized n-propane extraction improves bioactive compounds content, fatty acid profile, and biological activity of Mandacaru (Cereus jamacaru DC.) seed oil

This work aimed to evaluate the bioactive compounds content, fatty acid profile, and biological activity of Mandacaru seed oil obtained using n-propane at different pressures (45, 75, or 105 Bar, 40 °C) or conventional technique (Soxhlet method). The oil yield was similar among the treatments (17.78–20.45 %) but using n-propane resulted in shorter processing times (50 min vs. 8 h) and solvent consumption (25 % less). Furthermore, the oil obtained with pressurized n-propane, mainly at 105 Bar, showed a better fatty acid profile (higher polyunsaturated fatty acid contents and lowered saturated fatty acid), a higher concentration of bioactive compounds (γ-sitosterol and γ-tocopherol), and lower free fatty acid content than that obtained by conventional technique. Furthermore, it showed superior health indices (lower hypercholesterolemic saturated fatty acid, thrombogenic, and atherogenic, and higher desirable fatty acid indices). Finally, it presented higher antidiabetic properties (13.87 % higher inhibition of α-glucosidase). In conclusion, pressurized n-propane extraction improved the bioactive compound content, fatty acid profile, and biological activity of mandacaru seed oil, mainly at 105 Bar. Our results demonstrate that mandacaru seeds can be an important source of oils with essential chemical composition and biological activity, which can stimulate the production of this fruit and its utilization.

Physical, Nutritional, and Bioactive Properties of Mandacaru Cladode Flour (Cereus jamacaru DC.): An Unconventional Food Plant from the Semi-Arid Brazilian Northeast.

In this study, we evaluated the physical, nutritional, and bioactive properties of mandacaru cladode flour (Cereus jamacaru DC.). The granulometric profile revealed particles with non-uniform geometry, flakiness, a rectangular tendency, and a non-homogeneous surface, with particle sizes ranging from 20 to 60 µm. The flour presented low water activity (0.423), a moisture content of 8.24 g/100 g, high ash (2.82 g/100 g), protein (5.18 g/100 g), and total carbohydrate contents (74.48 g/100 g), and low lipid contents (1.88 g/100 g). Mandacaru flour is an excellent source of insoluble dietary fiber (48.08 g/100 g), calcium (76.33%), magnesium (15.21%), and potassium (5.94%). Notably, 1H NMR analysis revealed the presence of N-methyltyramine. Using HPLC chromatography, glucose was identified as the predominant sugar (1.33 g/100 g), followed by four organic acids, especially malic acid (9.41 g/100 g) and citric acid (3.96 g/100 g). Eighteen phenolic compounds were detected, with relevant amounts of kaempferol (99.40 mg/100 g), myricetin (72.30 mg/100 g), and resveratrol (17.84 mg/100 g). The total phenolic compounds and flavonoids were 1285.47 mg GAE/100 g and 15.19 mg CE/100 g, respectively. The mean in vitro antioxidant activity values were higher using the FRAP method (249.45 µmol Trolox TEAC/100 g) compared to the ABTS•+ method (0.39 µmol Trolox TEAC/g). Finally, the ascorbic acid had a content of 35.22 mg/100 g. The results demonstrate the value of mandacaru as a little-explored species and an excellent matrix for the development of flours presenting good nutritional value and bioactive constituents with excellent antioxidant potential.

First Report of the Cactus Cyst Nematode, Cactodera cacti, Infecting Cereus jamacaru (Cactaceae) in Brazil.

During a survey in 2018 for plant nematodes associated with roots and soil in cactus cultivation areas in Ceará State (3°44'48"S, 38°34'29"W), cysts were found on roots of mandacaru, Cereus jamacaru DC. This cactus is native to Brazil, can grow to 6-10 meters in height, and is widely distributed in the Northeast region (Romeiro-Brito et al. 2016) where it is used in construction, in disease remedies, as forage, and as an ornamental (Sales et al. 2014). Several cysts, second-stage juveniles (J2) and eggs extracted from the soil and roots, using sucrose centrifugation, were examined by scanning electron microscopy (SEM) and light microscopy (LM) to determine morphological and morphometric characteristics. Molecular characteristics were determined by DNA extraction from J2 and embryonated eggs using a protocol specific for Heteroderidae (Subbotin et al., 2018). The internal transcribed spacer sequence (ITS) region of the rDNA and D2-D3 regions of the 28S rDNA were amplified using the universal primers TW81 (5'-GTTTCCGTAGGTGAACCTGC-3') and AB28 (5'-ATATGCTTAAGTTCAGCGGGT-3'), D2A(5'-ACAAGTACCGTGAGGGAAAGTTG-3') and D3B(5'-TCGGAAGGAACCAGCTACTA-3'), respectively. To confirm that mandacaru is a host for C. cacti, six plantlets of mandacaru were inoculated with 1,800 eggs of the nematode, and kept in a greenhouse at 31 ± 3 ºC and irrigated daily. Six non inoculated mandacaru plantlets served as control treatment. Morphometric characteristics of cysts (n=35) were body length, excluding neck, 555.8 ± 87.8 (354,9 - 727,6) μm, body width 392.1 ± 63.4 (297.9 - 553.7) μm, neck length 63.5 ± 25.8 (49.8-105.0) μm, length to width ratio 1.4 ± 0.2 (1.0-1.8) μm and vulval cone length 48.4 ± 15.2 (40.7 -53.6) μm. Cysts had a rough surface, were lemon-shaped to rounded and had a zigzag cuticular pattern with a protruding vulval cone. They were circumfenestrate without underbridge and bullae, but with the presence of vulval denticles. Measurements of second-stage juveniles (n = 13) included the body length 511.2 ± 33.7 (452.7 - 551.5) μm, stylet length 28.0 ± 2.8 (25.4 - 34.0) μm, tail length 50.7 ± 5.1 (40.6 - 57.4) μm, tail hyaline region 22.7 ± 2.2 (18.9 - 27.1), with a = 20.9 ± 2.2 (17.7-24.3) μm, b = 5.4 ± 0.4 (5.1-5.8) μm, b'= 3.4 ± 0.4 (3.1-3.9) μm, c = 10.2 ± 1.3 (8.9-13.3) μm and c' = 3.8 ± 0.4 (3.0-4.5) μm. The observations of essential morphological characteristics for identification indicated that the species found on C. jamacaru was Cactodera cacti (Filipjev & Schuurmans-Stekhoven, 1941) Krall & Krall, 1978. The sequences of the studied rDNA regions were submitted to GenBank (ITS: MW562829 and D2-D3 regions of 28S: MW562830). The samples used for molecular analysis showed a high degree of sequence identity (99.59%) with C. cacti, from China, Iran and USA for the ITS region. The identity of the D2-D3 regions of 28S sequence was 99.54% with C. cacti isolates from Germany and 99.41% with isolates from USA. Phylogenetic analyses were performed using Maximum likelihood (ML) method for both individual loci, confirming the species as Cactodera cacti. All inoculated mandacaru plantlets showed C. cacti cysts on the roots after 60 days, confirming that mandacaru is a host for C. cacti. This species was reported in São Paulo State, in 2001, associated with ornamental cactus cultivated in pots, but plant species were not identified (Santos et al., 2001). The second report in Brazil was to Schlumbergera sp., an ornamental plant (Oliveira et al. 2007). In both studies, the nematode was not morphologically nor molecularly characterized. Cactodera cacti has been commonly associated with cactus worldwide (Esser, 1992). It has been reported in association with C. jamacaru was first reported in 2011 in China (Duan et al. 2012). This is the first report of the occurrence of C. cacti on C. jamacaru in field conditions in Brazil, and its presence in cactus cultivation areas with agricultural importance represents a threat to cactus production in the country.

Nutritional Potential and Bioactive Compounds in Cereus jamacaru DC: An Multifaceted Cactus From Brazilian Semiarid

Cereus jamacaru DC. is an endemic cactus of the Brazilian semiarid region empirically used by humans for forage, food and medicinal purposes. In this paper, we characterize the physicochemical and phytochemical profile of the C. jamacaru cladode and fruits, outlining their nutritional implications. We evaluate the basic physicochemical characteristic of the fruits and the main classes of chemical compounds present in aqueous and ethanolic extracts from cladode, peel, and pulp of ripe and semi-ripe fruits through qualitatively and quantitatively methods. We analyze the data through descriptive statistics and variance analysis. The fruits have appropriate pH, acidity, and total soluble solid levels for the fruit processing industry and fresh consumption. We identified the presence of saponins, tannins, flavones, flavonols, and xanthones in all samples, but alkaloids and steroids were both detected in cladodes exclusively. The phenolic compound and flavonoid contents vary according to the extraction method and sample class. The cladodes and pulp of ripe fruits have the highest flavonoid levels, while the content of phenolic compounds had a high level in peels of ripe and semi-ripe fruits. The presence of these bioactive compounds implies that C. jamacaru products have relevant pharmacological interest and functionality for human (fruits) and domestic ruminant (cladodes) food. These applications can boost the agricultural-economic exploration of C. jamacaru and contribute to income generation, and improve human and animal nutrition.

Simulation of air temperature and their influence on the potential distribution of Myracrodruon urundeuva, Copernicia prunifera and Cereus jamacaru in the Caatinga

Areas in the process of aridification in Caatinga phytogeographic domain in northeastern Brazil increase every year due to human intervention and increase in air temperature. The identification of long-term patterns and air temperature trends in the phytogeographic domain can express climate variability as well as a new phase of adaptation to some plant species. The temperature series from 1951 to 2018 obtained from the National Centers for Environmental Prediction data sets in four conservation areas with native vegetation, located in the North (A1), East (A2), South (A3) and West (A4) regions of this phytogeographic domain, show an increase in temperature between 0.5 and 1.4 °C over the 68-year period with the highest warming occurring in the months of March, April and May. The Maxent model is used to identify the influence of this increase on the presence potential of three species in the Caatinga, Myracrodruon urundeuva (aroeira), Copernicia prunifera (palmeira) and Cereus jamacaru DC (cactus) in the future time interval of 2041 to 2060, considering IPCC projected climate changes. The results show that climate change can lead to a reduction as well as redistribution of the potential areas of occurrence of the three species. Notable changes are: in the case of Carnauba, the high potential area reduces from 25.3% in the present state to 19.6% in 2050, and potential area for Aroeira diminishes in central Bahia and increases in Rio Grande do Norte. The projected changes for all three species are discussed.

Water restriction in seeds of Cereus jamacaru DC.

Mandacaru (Cereus jamacaru DC.) is a cactus widely found in the Caatinga, with its seeds usually subjected to adverse conditions. Therefore, the objective of this study was to evaluate the effect of water restriction on germination and vigor of mandacaru seeds by using different salts and osmotic potentials. To that end, we used saline solutions of NaCl, KCl, CaCl2 and MgCl2 prepared at the osmotic potentials of 0.0; -0.2; -0.4; -0.6; -0.8; -1.0 and -1.2 MPa. Four replicates of 50 seeds per treatment were used, distributed in “gerbox” boxes between blotter paper and under temperature of 25 °C. Counts of the number of germinated seeds were performed daily for 21 days after root protrusion. The variables analyzed were the following: water content (%), germination (%), mean germination time and normal seedlings (%). A completely randomized following the factorial scheme 4 × 7 (salts × osmotic potentials) was employed. Results obtained suggest that mandacaru seeds show the ability to germinate in saline soils, a characteristic found in arid and semi-arid areas. Decreased osmotic potential promoted reductions in germination (%) and vigor of Cereus jamacaru DC seeds. The MgCl2 salt was the one that most negatively affected the germination and initial seedling development.

English

Mandacaru (Cereus jamacaru DC. Subsp. Jamacaru) is native to the Brazilian Caatinga and is part of the Cactaceae family. Mandacaru fruits are attractive in taste and flavour, although they are not widely commercialised. However, there is limited scientific literature on the composition of this fruit. Therefore, the present work was aimed at analysing the physicochemical composition, as well as in vitro antioxidant activity, phytochemical profile, and cytotoxicity of mandacaru fruit from three different locations in the Brazilian State of Sergipe. The pulp and peel of mandacaru fruit used in this study presented low Vitamin C concentration, mean values between batches 18.2 mg. 100 g-1 (pulp) and 27.5 mg. 100 g-1 (peel). The pulp of mandacaru fruit from the region of Monte Alegre presented the highest concentration of apparent phenolic compounds (117.2 mg. EAG g-1) and antioxidant activity evaluated by the inhibition of the ABTS radical (22.4 μmol. trolox g-1). The chemical profile of mandacaru fruit consisted of o-coumaric and p-coumaric acids, but they were not considered to be cytotoxic; thus, this native fruit is suitable for consumption, exhibiting relevant amounts of apparent phenolic compounds and antioxidant activity. Further studies are needed to prolong the shelf life of the fruit for commercialisation. Key words: Cereus jamacaru, antioxidant activity, phytochemical profile, Caatinga.

Traditional management of Cactaceae: Cereus jamacaru DC as the native cactus most managed by rural communities in areas of Caatinga in Brazil

Background: Studies on management practices reflect the quality of the actions regarding the managed resource by people and allow us to identify possible selective pressures over time.Methods: Was investigated how have been carrying out management practices using native cacti species in two communities. Data collection was through the ethnobotanical (semi-structured interviews) and morphometric approach (botanical measurements). It was aimed to interview residents who used and/or cultivated some native species. For morphometric analysis were recorded total height from the highest branch and the maximum number of stem ribs per plant, ground-level and chest level diameter. Managed and unmanaged plants were comparatively analyzed. Was created a distribution map with gathering and cultivation areas indicated by the residents through QGIS software. The Kruskal-Wallis test was applied to investigate the differences between the specimens managed and unmanaged, and the Pearson linear correlation test to test the correlation between the diameter x height.Results: People mentioned the management of six native species, through the collection, non-selective incipient management, and ex situ cultivation. Low complexity activities were the most frequent; also, there was little variation between the forms of management. Cereus jamacaru DC. was the most locally managed species and by a higher number of people, and it was observed that specimens from the Area of Direct Use (ADU) had greater variation.Conclusions: Intra-specific variants were identified by people and they said to prefer the larger and healthier branches and younger (green) cladodes, suggesting human selection that can favor particular phenotypes where these plants are propagated.Keywords: dry forest, ethnobotany, phenotypic variation, artificial selection

UTILIZAÇÃO DO CACTO MANDACARU (Cereus jamacaru DC) COMBINADO À RADIAÇÃO SOLAR COMO ALTERNATIVA PARA TRATAMENTO DE ÁGUA

Water is a limited resource and indispensable for human survival, but also increasingly scarce, especially in the semiarid regions of Brazil. In this sense, the present work seeks to analyze the effectiveness of a simplified water treatment using Cereus jamacaru DC cactus combined with solar disinfection (SODIS). For that, a differentiated methodology was developed where the variables studied were the amount of cactus fragments used and the time of exposure to solar radiation, obtaining results in terms of turbidity, thermotolerant coliforms and pH of the sample. It was observed that the Cereus jamacaru DC was efficient in the treatment of water, reducing turbidity and biological contamination, with the application of SODIS potentializing the performance of the treatment. Better results were obtained for the treatment in which a greater amount of the cactus was used combined with 18 hours of SODIS. The findings allow us to conclude that the use of the Cereus jamacaru DC cactus for water treatment is possible and must be explored and better studied in order to standardize methodologies and optimize results.

Resposta germinativa de sementes de cactáceas colunares sob diferentes regimes de temperatura e de potencial hídrico

O mandacaru (Cereus jamacaru DC. subsp. jamacaru) e o facheiro (Pilosocereus pachycladus F.Ritter subsp. pernambucoensis (F.Ritter) Zappi) são duas cactáceas colunares endêmicas do semiárido brasileiro, região caracterizada por apresentar áreas em que ocorre déficit hídrico. Assim sendo, este estudo objetivou avaliar o efeito do estresse hídrico sobre a germinação e o vigor de sementes dessas duas espécies sob diferentes temperaturas e potenciais hídricos. Para simular o estresse hídrico foram utilizadas soluções de polietilenoglicol (PEG 6000) nos seguintes potenciais hídricos: 0,0 (controle); -0,2; -0,4; -0,6 e -0,8 MPa. As sementes foram distribuídas em caixas tipo “gerbox” entre papel “mata borrão”, sob as temperaturas de 25 e 30 °C. A contagem do número de sementes germinadas foi realizada diariamente durante 21 dias após a protrusão radicular. As variáveis analisadas foram: teor de água (%), germinação (%), índice de velocidade de germinação (IVG) e tempo médio de germinação (TMG). O delineamento foi inteiramente casualizado seguindo o esquema fatorial de 2 × 5 (temperatura × potencial hídrico) para cada espécie. Os resultados obtidos neste estudo sugerem que o C. jamacaru subsp. jamacaru e o P. pachycladus subsp. pernambucoensis são capazes de germinar em solos com baixa disponibilidade hídrica e que a redução dos níveis osmóticos das soluções de PEG 6000 no meio germinativo provoca decréscimos na viabilidade e vigor das sementes de mandacaru e facheiro. A 30 °C há menor tolerância das sementes ao estresse hídrico.

Distribuição espacial e estrutura populacional de Pilosocereus pachycladus F. Ritter subsp. pernambucoensis (F. Ritter) Zappi e Cereus jamacaru DC. subsp. jamacaru

A família Cactaceae apresenta mais de 1.500 espécies no mundo, ocorrendo espécies endêmicas em todo o território nacional. Em populações naturais, tais elementos sofrem fortes pressões antrópicas, o que aumenta consideravelmente o seu risco de extinção. O objetivo do trabalho foi realizar um estudo sobre a distribuição espacial e estrutura populacional de Pilosocereus pachycladus F. Ritter subsp. pernambucoensis (F. Ritter) Zappi e Cereus jamacaru DC. subsp. jamacaru em duas áreas de Caatinga do Agreste do estado da Paraíba, Brasil. Os ambientes de estudo estão localizados no Instituto Nacional do Semiárido (INSA), Campina Grande-PB, e no Sítio Umburana, Bananeiras-PB. Foram alocadas 10 parcelas amostrais de 400 m² em cada ambiente de estudo, e todos os indivíduos de P. pachycladus subsp. pernambucoensis e C. jamacaru subsp. jamacaru foram contabilizados. A distribuição espacial das espécies, não apresentaram tendência ao agrupamento nas populações localizadas no INSA. Nas populações do Sítio Umburana, a tendência é ao agrupamento. De acordo com índice de agrupamento de Payandeh (Pi) a densidade populacional e absoluta nas populações do Sítio Umburana é maior, se comparado às populações do INSA. Para os padrões espaciais, nas populações de Cactaceae do Sítio Umburana, os indivíduos de ambas as espécies apresentam distribuição agrupada e nas populações do INSA apresentaram a tendência ao não agrupamento. Fatores como distúrbios naturais ou antrópicos, condições ambientais e disponibilidade de recursos, influenciaram a estrutura populacional de P. pachycladus e C. jamacaru.

Evaluation of pre-germinative treatments in seeds of Cereus jamacaru DC subsp. jamacaru (Cactaceae)

Cereus jamacaru DC subsp. jamacaru (mandacaru) is an endemic species in Brazil belonging to Cactaceae of great ecological importance, as it is a pioneer in the colonization of arid and inhospitable environments, and contributes directly to the food chain for its fruits highly appreciated by fauna. Therefore, this work aimed to evaluate, through chemical scarification, the germinative behavior of C. jamacaru subsp. jamacaru. The cactus seeds were collected in May 2016 in the city of Quixelô-CE-Brazil. The acids used in chemical scarification were acetic acid, hydrochloric acid, propionic acid and sulfuric acid for 5, 10 and 15 minutes. The seeds were placed in Petri dishes, and placed to germinate in a B.O.D. with a light/dark cycle of 12 hrs at 30 ºC. Daily readings were performed and analyzed: percentage of germination, Germination Speed ​​Index (GSI) and mean germination time (Tm). The results indicate that acids negatively interfere in seed germination when compared to the control group, mainly acetic and propionic acid, since at the end of the experiment only 8% of the seeds germinated when subjected to acetic acid, and 4% to the propionic. In addition, there was also a significant increase in Tm. Thus, water is the best method of obtaining a higher percentage of germination of C. jamacaru subsp. jamacaru.