Chemometric discrimination of Hylocereus undulatus from different geographical origins via their metabolic profiling and antidiabetic activity.

Hylocereus spp. known as dragon fruit is an exotic fruit that belongs to the Cactaceae family. LC-QTOF-MS and multivariate statistical tools were established to analyze differences in the composition of dragon fruit peel and pulp from Egypt, Germany, Philippines, and China. The α-glucosidase inhibitory effects of different extracts were carried out along with the anti-glycation end products (AGE) using BSA-fructose, BSA-methylglyoxal, and arginine-methylglyoxal assays. In addition, the total antioxidant capacity was investigated as a complementary mechanism to AGE formation. Principal component analysis revealed that dragon fruits from China and Egypt were the most distinct among all samples due to betalains content. Orthogonal projection to latent structures-discriminant analysis identified 16 compounds highly correlated to the antiglycation activity such as betanin, γ-aminobutyric acid, neobetanin, and portulacaxanthin II. Pulp extracts were more active than peels as inhibitors of α-glucosidase. While peels were more active as AGE formation inhibitors and as antioxidants.

Discovery of Hyperstable Noncanonical Plant-Derived Epidermal Growth Factor Receptor Agonist and Analogs.

Here, we report the discovery of the first plant-derived and noncanonical epidermal growth factor receptor (EGFR) agonist, the 36-residue bleogen pB1 from Pereskia bleo of the Cactaceae family. We show that bleogen pB1 is a low-affinity EGFR agonist using a suite of chemical, biochemical, cellular, and animal experiments which include incisor eruption and wound-healing mouse models. A focused positional scanning pB1 library of Ala- and d-amino acid scans yielded a high-affinity pB1 analog, [K29k]pB1, with a 60-fold-improved EGFR affinity and mitogenicity. We show that the potency of [K29k]pB1 and the epidermal growth factor (EGF) is comparable in a diabetic mouse wound-healing model. We also show that both bleogen pB1 and [K29k]pB1 are hyperstable, being >100-fold more stable than EGF against proteolytic degradation. Overall, our discovery of a noncanonical proteolytic-resistant EGFR agonist scaffold could open new avenues for developing wound healing and skin regeneration therapeutics and biomaterials.

Comparative Metabolic Profiling in Pulp and Peel of Green and Red Pitayas (Hylocereus polyrhizus and Hylocereus undatus) Reveals Potential Valorization in the Pharmaceutical and Food Industries.

Pitaya (Hylocereus genus) is a popular plant with exotic and nutritious fruit, which has widespread uses as a source of nutrients and raw materials in the pharmaceutical industry. However, the potential of pitaya peel as a natural source of bioactive compounds has not yet fully been explored. Recent advances in metabolomics have paved the way for understanding and evaluating the presence of diverse sets of metabolites in different plant parts. This study is aimed at exploring the diversity of primary and secondary metabolites in two commercial varieties of pitaya, i.e., green pitaya (Hylocereus undatus) and red pitaya (Hylocereus polyrhizus). A total of 433 metabolites were identified using a widely targeted metabolomic approach and classified into nine known diverse classes of metabolites, including flavonoids, amino acids and its derivatives, alkaloids, tannins, phenolic acids, organic acids, nucleotides and derivatives, lipids, and lignans. Red pitaya peel and pulp showed relatively high accumulation of metabolites viz. alkaloids, amino acids and its derivatives, and lipids. Differential metabolite landscape of pitaya fruit indicated the presence of key bioactive compounds, i.e., L-tyrosine, L-valine, DL-norvaline, tryptophan, γ-linolenic acid, and isorhamnetin 3-O-neohesperidoside. The findings in this study provide new insight into the broad spectrum of bioactive compounds of red and green pitaya, emphasizing the valorization of the biowaste pitaya peel as raw material for the pharmaceutical and food industries.

Biochemical and nutritional characterization of dragon fruit (Hylocereus species).

Nutritional and biochemical composition of dragon fruit (Hylocereus) species H. undatus (fruits with white pulp and pink skin), and H. polyrhizus (fruits with red pulp and pink skin) were investigated to develop the nutritional composition data for dragon fruit and compare the difference between H. undatus and H. polyrhizus. The pH, TSS, total sugar, moisture, ash, protein, and dietary fibre content varied between 4.8 and 5.4, 8-12%, 5.13-7.06%, 82-85%, 0.7-0.85%, 0.90-1.1% and 0.8-1.0%, respectively. Total phenolics and flavonoids content varied between 25 and 55 mg GAE and 15-35 mg CE per 100 g, respectively. H. polyrhizus have a significantly high quantum of phenolics and antioxidant potential than H. undatus. 100 g fruit contained about 120-200 mg K, 30-45 mg Mg, 20-45 mg Ca, 20-35 mg P, 0.70-1.5 mg Fe, and 0.20-0.40 mg Zn. Vitamin C was found maximum (6 mg/100 g), followed by vitamin E (150 µg), pantothenic acid (50 µg), and vitamin K1 (25 µg). It is an ideal fruit for maintaining good health as it has low calories.

In vitro gastrointestinal stability, bioaccessibility and potential biological activities of betalains and phenolic compounds in cactus berry fruits (Myrtillocactus geometrizans).

Cactus berry (Myrtillocactus geometrizans) is a scarcely studied Mexican wild fruit. These fruits could contribute to reduce the risk of degenerative chronic diseases due to their bioactive profile. The aim of this work was to study the betalains and phenolic profile in cactus berry, their in vitro biological activities and gastrointestinal digestive stability and bioaccessibility. 43 metabolites were identified by HPLC-DAD-ESI-QTOF (8 betaxanthins, 8 betacyanins, 13 flavonoids, 6 phenolic acids). Phyllocactin and Isorhamnetin rhamnosyl-rutinoside (IG2) were the most abundant metabolites (5876 and 396 µg/g dw) which were also bioaccessible (16 and 21%, respectively). Pulps showed higher (p ≤ 0.05) antioxidant activity by the Oxygen Radical Absorbance Capacity (27 mM Trolox equivalents). The anti-hyperglycemic activity was highest (p ≤ 0.05) in peel and pulp tissues (85% α-glucosidase and 8% α-amylase inhibition). An 83% inhibition of hyaluronidase showed high anti-inflammatory activity. Cactus berry fruit should be considered a promising fruit candidate for a sustainable healthy diet.

Self-Repair in Cacti Branches: Comparative Analyses of Their Morphology, Anatomy, and Biomechanics.

Damage-repair is particularly important for the maintenance of the water-storing abilities of succulent plants such as cacti. Comparative morphological, anatomical, and biomechanical analyses of self-repair were performed on artificially wounded branches of Opuntia ficus-indica and Cylindropuntia bigelovii. Macroscopic observations, contrast staining, and lignin-proof staining were used to investigate morphological and anatomical responses after wounding at various time intervals. Two-point bending tests were repeatedly performed on the same branches under unwounded, freshly wounded, and healed conditions by using customized 3D-printed clamping jaws. Morphologically, both species showed a rolling-in of the wound edges, but no mucilage discharge. Anatomically, ligno-suberized peridermal layers developed that covered the wound region, and new parenchyma cells formed, especially in O. ficus-indica. In all samples, the wounding effect directly after damage caused a decrease between 18% and 37% in all the tested mechanical parameters, whereas a positive healing effect after 21 days was only found for C. bigelovii. Based on our data, we hypothesize a high selection pressure on the restoration of structural integrity in the wound area, with a focus on the development of efficient water-retaining mechanisms, whereas the concept of "sufficient is good enough" seems to apply for the restoration of the mechanical properties.

Microfiltered red-purple pitaya colorant: UPLC-ESI-QTOF-MSE-based metabolic profile and its potential application as a natural food ingredient.

Complete characterization of microfiltered red-purple pitaya colorant (MRPPC) and its potential applications in foods is described. Using sensorial analysis, products that use carmine or beetroot dye as a food colorant in their formulations were compared. The effect of storage under refrigeration on the microbiological, physicochemical, and chemical changes of MRPPC were evaluated. The results showed that UPLC-ESI-QTOF-MSE was effective for the simultaneous determination of twenty metabolites, putatively identified as carbohydrates, flavonoids, and betalains. The MRPPC was shown to have microbiological and physicochemical stability through twelve weeks of storage, and chemometric analyses efficiently distinguished the metabolic profile in each storage period. Sensory analysis revealed that the MRPPC was useful as a food colorant in yogurt, where it improved color quality without affecting aroma and other characteristics. These results indicate that MRPPC is promising food ingredient as a natural red-purple colorant.

Phytochemical profile and biological activities of 'Ora-pro-nobis' leaves (Pereskia aculeata Miller), an underexploited superfood from the Brazilian Atlantic Forest.

Pereskia aculeata Miller, known worldwide as ora-pro-nobis, is a highly nutritive species of the Cactaceae family from the Brazilian Atlantic Forest. In this work, we report inedited information on the phenolic profile of P. aculeata leaves, besides a broad study of their antioxidant potential using a set of five different methods. A total of ten phenolic compounds were identified, such as two phenolic acids (caffeic acid derivatives) and eight flavonoids (quercetin, kaempferol and isorhamnetin glycoside derivatives). Caftaric acid was the extract's major phenolic constituent, accounting for more than 49% of the phenolic content, followed by quercetin-3-O-rutinoside (14.99%) and isorhamnetin-O-pentoside-O-rutinoside (9.56%). Overall, the ora-pro-nobis leaf extract showed relevant values of antioxidant capacity, with higher activities than the Trolox in the DPPH and ABTS trials. The antimicrobial activity exhibited by the extract against both Gram-positive and Gram-negative bacteria suggests the presence of a broad spectrum of phytochemicals with antibiotic activity.

Phytochemical Profiling of Coryphantha macromeris (Cactaceae) Growing in Greenhouse Conditions Using Ultra-High-Performance Liquid Chromatography⁻Tandem Mass Spectrometry.

Chromatographic separation combined with mass spectrometry is a powerful tool for the characterization of plant metabolites because of its high sensitivity and selectivity. In this work, the phytochemical profile of aerial and radicular parts of Coryphantha macromeris (Engelm.) Britton & Rose growing under greenhouse conditions was qualitatively investigated for the first time by means of modern ultra-high-performance liquid chromatography⁻tandem mass spectrometry (UHPLC-PDA-HESI-Orbitrap-MS/MS). The UHPLC-PDA-HESI-Orbitrap-MS/MS analysis indicated a high complexity in phenolic metabolites. In our investigation, 69 compounds were detected and 60 of them were identified. Among detected compounds, several phenolic acids, phenolic glycosides, and organic acids were found. Within this diversity, 26 metabolites were exclusively detected in the aerial part, and 19 in the roots. Twenty-four metabolites occurred in both plant parts. According to the relative abundance of peaks in the chromatogram, ferulic and piscidic acids and their derivatives may correspond to one of the main phenolic compounds of C. macromeris. Our results contribute to the phytochemical knowledge regarding C. macromeris and its potential applications in the pharmaceutical and cosmetic industries. Besides, some metabolites and their fragmentation patterns are reported here for the first time for cacti species.

Spray drying microencapsulation of betalain rich extracts from Escontria chiotilla and Stenocereus queretaroensis fruits using cactus mucilage.

In this work the capacity of Opuntia ficus indica mucilage as a wall agent in the microencapsulation of Escontria chiotilla and Stenocereus queretaroensis pulp and skin pigments through a spray drying process was studied. The acidified mucilage was used as an extracting medium for betalains present in the skin of these fruits. The shear-thinning behavior of the mucilage-betalain solutions was suitable for spray drying, wherein microcapsules with smooth and spherical morphologies were observed by SEM and characterized by FTIR. Additionally, microcapsules of mucilage achieved the retention of betalains at more than 90% after three months of storage. The colors obtained from the redissolution of the powders from skin and pulp samples do not present significant differences; therefore, the use of skin fruits can be a source of colorants, taking advantage of waste from other processes, promoting a culture of the use of environmentally-friendly technologies.

Comparative volatile compounds and primary metabolites profiling of pitaya fruit peel after ozone treatment.

BACKGROUND: Ozone treatment can effectively inhibit fruit decay in many fruits during postharvest storage. However, little information is available for pitaya fruit. RESULTS: Ozone treatment significantly reduced the decay rate and induced the enzyme activities of peroxidase and polyphenol oxidase, and also reduced the levels of reactive oxygen species. In total, 103 metabolites were detected and changed the content after ozone treatment, including 54 primary metabolites and 49 aromatic compounds. After significance and importance analysis, 37 metabolites were important. Some metabolites were induced by peel senescence to respond to senescence stress, including d-fructose, d-glucose, mannose, inositol, galactonic acid, ethanedioic acid and stearic acid. Some metabolic products of peel senescence were reduced by ozone treatment, including d-arabinose, glucaric acid, galacturonic acid, 1-hexanol, 4-ethylcyclohexanol, ß-linalool, palmitoleic acid and 2-hydroxy-cyclopentadecanone. Some metabolites induced by ozone treatment might play a vital role in delaying the senescence and decay, including malic acid, succinic acid, pentenoic acid, eicosanoic acid, 2-hexenal, hexanal, 2-heptenal, 4-heptenal, 2-octenal and nitro m-xylene. CONCLUSION: Ozone treatment significantly reduced decay and prolonged shelf-life without reducing fruit quality. In total, 37 metabolites might play an important role in ozone delayed fruit decay. © 2018 Society of Chemical Industry.

Agronomic Cultivation, Chemical Composition, Functional Activities and Applications of Pereskia Species - A Mini Review.

BACKGROUND: The exploration of the plant biodiversity as a natural source to obtain sustainable food products and new bioactive pharmaceutical compounds has been growing significantly due to their abundance, safety and economy. Natural pharmaceutical and edible compounds present some advantages when compared to synthetic ones, such as being chemically inert and widely available. In this sense, plants of the genus Pereskia belonging to the Cactaceae family, have been studied. It is an unconventional wild edible plant that contains a large amount of protein and minerals. Studies have demonstrated their biological activities and potential application in different areas such as pharmaceutical, medicinal and food. OBJECTIVE: This review is focused on the chemical composition, functional properties, applications on pharmaceutical, nutraceutical and food areas and formulation techniques to enhance the stability and bioavailability of bioactive compounds from the underutilized wild edible plant known as ora-pro-nobis (Pereskia aculeata or Pereskia grandifolia). CONCLUSION: The latest studies involving ora-pro-nobis demonstrated its great potential due to its biological activities, which could stimulate further investigations. The utilization of this plant as a natural source to supplement the diet, or to prepare new food products and pharmaceutical formulations is an attractive approach to explore and fully realize the potential of the rich biodiversity found in Brazil and in other countries.

Callus Induction from Various Organs of Dragon Fruit, Apple and Tomato on some Mediums.

BACKGROUND AND OBJECTIVE: Dragon fruit (Hylocereus spp.), apple (Malus sylvestris Mill.) and tomato (Solanum lycopersicum L.) are high potential sources of antioxidant compounds such as phenolics. The compounds have the capability of protecting cells and tissues against free radicals. Secondary metabolite produced by callus cell culture from plant organs also acts as a source of antioxidants. This study aimed to determine the optimal ratio of sucrose and 2,4-D in Murashige and Skoog (MS) medium for callus induction from different plant organ explants. With all of characteristic, callus can be used further for the development of natural cell regeneration agent. METHODOLOGY: This study was conducted using analytical technique. Suitable explants were obtained. They were developed in various concentrations of combination between MS medium and 2,4-D. Callus growth, including their weight and surface was then measured and analyzed by using one-way analysis of variance (ANOVA). RESULTS: Callus was able to grow from its explants in 5-7 days after induction process. They were clear in color and had friable texture. The highest value of fresh weight of dragon fruit callus was obtained through MS supplemented with 1 µL L-1 2,4-D and 30 g sucrose. However, apple and tomato callus induction and growth maintenance reached optimal medium on MS supplemented with 30 g sucrose and 2 µL L-1 2,4-D. CONCLUSION: Callus of apple, dragon fruit and tomato was maintained upon MS supplemented with 30-40 g sucrose and 1-2 µL L-1 2,4-D for optimum induction and growth. The optimization of growth medium will give advantages for further development of natural cell regeneration agent.

Balanço hídrico e excreção renal de metabólitos em ovinos alimentados com palma forrageira (Nopalea cochenillifera Salm Dyck) / Water balance and renal excretion of metabolites in sheep fed forage cactus (Nopalea cochenillifera Salm Dyck)

Objetivou-se avaliar balanço hídrico e excreção renal de metabólitos em borregos sem raça definida, alimentados com diferentes quantidades de palma forrageira (Nopalea cochenillifera Salm Dyck), na forma in natura e em farelo. Foram utilizados 20 borregos, com peso vivo médio inicial de 20 Kg e foram distribuídos no delineamento inteiramente casualizado, sendo cinco tratamentos e quatro repetições. As dietas experimentais consistiram em uma dieta controle à base de feno de tífton, farelo de soja, suplemento mineral e calcário, os demais tratamentos visaram testar níveis diferentes de palma forrageira corrigida com ureia em duas formas: in natura e farelada e em dois níveis de substituição (50 e 100%) da matéria seca do feno de tífton. Amostras de sangue e urina foram coletadas para determinação de diferentes metabólitos e minerais e utilização de equações para obtenção dos índices de excreção urinária destes metabólitos, taxa de depuração endógena de creatinina e reabsorção de água livre de eletrólitos, além do registro de ingestão de água e volume de urina. A ingestão voluntária de água sofreu influência das dietas, sendo que os animais submetidos às dietas contendo farelo de palma e feno e farelo de palma foram superiores aos demais tratamentos. A ingestão de água via alimentos também sofreu influência da dieta, sendo maior nos animais que receberam palma in natura e farelo mais palma in natura. Com relação à ingestão total de água foi maior para os animais alimentados com dietas contendo palma in natura em relação aos demais tratamentos. As dietas experimentais influenciaram na excreção renal de metabólitos derivados purínicos e minerais, sem alterar a função renal. A presença da palma forrageira tanto na condição de farelo como in natura proporciona aumento do volume urinário sem alterar a função renal, além de que deve ser considerado como uma excelente estratégia alimentar no semiárido.

This study aimed to assess fluid balance and renal excretion of metabolites in lambs without defined breed standard, fed different forage cactus (Nopalea cochenillifera Salm Dyck), in natura and bran. 20 lambs were used, with initial body weight of 20 kg and were distributed in a completely randomized design, with five treatments and four repetitions. The experimental diets consisted of a control diet based on Bermuda grass hay, soybean meal, limestone and mineral supplement, other treatments aimed at testing different levels of cactus pear plus urea in two forms: fresh and mash and two levels of substitution (50 and 100%) of dry matter of hay. Blood and urine samples were collected for determination of different metabolites and minerals and use of equations to determine the rates of urinary excretion of these metabolites, rate of endogenous creatinine clearance and electrolyte reabsorption of free water, in addition to recording of water intake and urine volume. The voluntary water intake was influenced by the diets, and the animals subjected to diets containing soybean meal and hay palm and cactus meal were higher than other treatments. Water intake via food was also influenced by diet, being higher in animals fed palm fresh and bran over palm in nature. With respect to total water intake was greater for cows fed diets containing palm in nature compared to the other treatments. The experimental diets influenced the renal excretion of purine metabolites and minerals derived, without changing renal function. The presence of cactus pear both as bran as in nature provides increased urine volume without changing renal function, and to be considered as an excellent food strategy in semiarid.

Quantification of polyphenols and flavonoid content and evaluation of anti-inflammatory and antimicrobial activities of Stenocereus stellatus extracts.

The hexanic, ethyl acetate and methanolic extracts from branches of Stenocereus stellatus were tested in both the 12-O-tetradecanoylphorbol-13-acetate (TPA) - induced ear oedema model and antimicrobial activity assay. The % of oedema inhibition, the Minimum Inhibitory Concentration (MIC), as well as the polyphenolic and flavonoid content were determined. Also, extracts were analysed by gas chromatography-mass spectrometry (GC-MS). In TPA model, the three extracts showed moderate oedema inhibition. In the antimicrobial activity assay, methanolic extract shows better MIC against all strains. The lowest MICs were for Candida albicans (31 µg/mL) and Rhizopus sp. (15 µg/mL). Also, 50.78 mg eq. of gallic acid/g extract of polyphenol and 115.12 mg eq. of catequine/g extract of flavonoids content were founded in ethyl acetate extract. In the chromatographic analysis, ß-sitosterol, ß-amyrine, betulin and some other molecules were identified. The results show that S. stellatus possess antimicrobial activities against some fungus species.

Antidiabetic and Renal Protective Properties of Berrycactus Fruit (Myrtillocactus geometrizans).

Native plants are exceedingly valuable because they are sources of natural products with applications for the treatment of various diseases. Berrycactus fruit (Myrtillocactus geometrizans) has been consumed in Mexico since ancient times due to its sweetness. The hypoglycemic and antioxidant effects of this fruit were evaluated in streptozotocin-induced diabetic rats by replacing the drinking water with berrycactus juice (2 or 4 g/kg). After 4 weeks of treatment, the diabetic animals showed an improvement in their conditions, as reflected by diminished circulating glucose levels (up to 50%), diminished triglycerides (up to 67%), and diminished total cholesterol (up to 35%) compared with diabetic nontreated controls, and these effects were dose dependent. The dose of 4 g/kg produced the best results. The administration of the juice improved renal function and helped to restore normal levels of glutathione and glutathione S-transferase in the kidney. The expressions of two transcription factors that are relevant to normal functioning of the kidney changed due to the administration of the juice; compared to the diabetic nontreated controls, the level of nuclear factor kappa of B-cells diminished, and the total level of peroxisome proliferator-activated receptor gamma increased. The results of this study highlight the importance of the compounds that are present in berrycactus fruit as adjuvants in the treatment of diabetes and its renal complications.

Accumulation of silicon in cacti native to the United States: characterization of silica bodies and cyclic oligosiloxanes in Stenocereus thurberi, Opuntia littoralis, Opuntia ficus-indica, and Opuntia stricta.

Four different cactus species growing in the United States, Stenocereus thurberi growing in Organ Pipe Cactus National Monument, Arizona, Opuntia littoralis and Opuntia ficus-indica, growing on Santa Catalina Island, California, and Opuntia stricta, growing in northern Alabama, were examined for the presence of silica bodies (opaline phytoliths). Silica bodies were found in all four of these cactus species, parallelepiped-shaped crystals in S. thurberi, and starburst-shaped crystalline structures in the three Opuntia species. In addition, the essential oils of the four cactus species were obtained by hydrodistillation and analyzed by gas chromatography - mass spectrometry. To our surprise, S. thurberi, O. littoralis, and O. ficus-indica (but not O. stricta) essential oils contained cyclic oligosiloxanes. To our knowledge, cyclic oligosiloxanes have not been previously found as essential oil components.

Metabolite profiling of red and white pitayas (Hylocereus polyrhizus and Hylocereus undatus) for comparing betalain biosynthesis and antioxidant activity.

Metabolite profiling of red and white pitayas (Hylocereus polyrhizus and Hylocereus undatus) was performed using gas chromatography-time-of-flight-mass spectrometry and ultraperformance liquid chromatography-quadrupole-time-of-flight-mass spectrometry with multivariate analysis. Different species and parts of pitayas (red peel, RP; white peel, WP; red flesh, RF; and white flesh, WF) were clearly separated by partial least-squares discriminate analysis. Furthermore, betalain-related metabolites, such as betacyanins and betaxanthins, or their precursors were described on the basis of their metabolites. The results of antioxidant activity tests [1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), and ferric reducing ability of plasma (FRAP)], total phenolic contents (TPC), total flavonoid contents (TFC), and total betacyanin contents (TBC) showed the following: RP ≥ WP > RF > WF. TPC, TFC, TBC, and betalain-related metabolites were higher in the peel than in the flesh and suggested to be the main contributors to antioxidant activity in pitayas. Therefore, peels as well as pulp of pitaya could beneficially help in the food industry.

Morphological, cytological and metabolic consequences of autopolyploidization in Hylocereus (Cactaceae) species.

BACKGROUND: Genome doubling may have multi-level effects on the morphology, viability and physiology of polyploids compared to diploids. We studied the changes associated with autopolyploidization in two systems of somatic newly induced polyploids, diploid-autotetraploid and triploid-autohexaploid, belonging to the genus Hylocereus (Cactaceae). Stomata, fruits, seeds, embryos, and pollen were studied. Fruit pulp and seeds were subjected to metabolite profiling using established gas chromatography-mass spectrometry (GC-MS) and ultra-performance liquid chromatography (UPLC) Q-TOF-MS/MS (time of flight)-protocols. RESULTS: Autopolyploid lines produced lower numbers of tetrads, larger pollen grains with lower viability, larger stomata with lower density, and smaller fruits with lower seed numbers and decreased seed viability. The abundance of sugars was lower in the fruits and seeds of the two duplicated lines than in their donor lines, accompanied by increased contents of amino acids, tricarboxylic acid (TCA) cycle intermediates, organic acids and flavonoids. Betacyanins, the major fruit pigments in diploid and triploid donors, decreased following genome doubling. Both autopolyploid Hylocereus lines thus exhibited unfavorable changes, with the outcome being more dramatic in the autohexaploid than in the autotetraploid line. CONCLUSION: Induced autotetraploid and autohexaploid lines exhibited morphological and cytological characteristics that differed from those of their donor plants and that were accompanied by significant metabolic alterations. It is suggested that a developmental arrest occurs in the fruits of the autohexaploid line, since their pericarp shows a greater abundance of acids and of reduced sugars. We conclude that genome doubling does not necessarily confer a fitness advantage and that the extent of alterations induced by autopolyploidization depends on the genetic background of the donor genotype.

Digestibilidad del polen de cactáceas columnares en los murciélagos glosofaginos Glossophaga longirostris y Leptonycteris curasoae (Chiroptera: Phyllostomidae) / Digestibility of columnar cacti pollen grains in the glosophagine bats Glossophaga longirostris and Leptonycteris curasoae (Chiroptera: Phyllostomidae)

We examined the protoplasmic assimilation of columnar cacti pollen grains in two species of Venezuelan desert glosophagine bats, Glossophaga longirostris and Leptonycteris curasoae, by determining the amount of empty (digested) pollen grains found in their fecal samples. To determine the amount of empty pollen grains, the fecal samples were stained to differ between empty and full (non-digested) pollen grains. The number of empty and full pollen grains observed in the fecal samples were corrected using the amount of aborted pollens present (before anthesis) in flowers of the columnar cacti species (Subpilocereus repandus, Stenocereus griseus and Pilosocereus tillianus ) used by bats as food in the study site; G. longirostris and L. curasoae digested 64.2% and 71.3% of all the pollens fed, respectively. These high values confirm the importance of pollen in the diet of these bats, given its high nitrogen level

Para estudiar la asimilación protoplasmática de los granos de polen de cactáceas columnares en dos especies de murciélagos glosofaginos, determinamos el porcentaje de granos de polen vacíos (digeridos) en muestras fecales de Glossophaga longirostris y Leptonycteris curasoae , capturados en una zona árida de Venezuela. Para determinar el porcentaje de granos de polen digeridos por los murciélagos, aplicamos un colorante sobre las muestras fecales que permite diferenciar sin dificultad el polen vacio del polen lleno. Después de cuantificar los granos de polen de ambas categorías en las muestras fecales, los valores fueron corregidos tomando en cuenta el porcentaje de polen vacío (previo a la antesis) en las flores maduras de las especies de cactáceas columnares (Subpilocereus repandus, Stenocereus griseus y Pilosocereus tillianus ). G. longirostris asimila el 64.2% de los granos de polen que ingiere y L. curasoae asimila el 71.3%. Estos elevados porcentajes confirman la importancia del polen en la dieta de estos murciélagos, dado su alto contenido de nitrógeno