Stenocereus Pruinosus Research Articles

Redox imbalance accompanies loss of viability in seeds of two cacti species buried in situ

Abstract This work provides insights into the deterioration of cacti seeds of Escontria chiotilla (F.A.C. Weber ex K. Schum) and Stenocereus pruinosus (Otto ex Pfeiff.) Buxbaum stored ex situ at 25 °C, under dry and dark conditions or buried in situ conditions in a xerophytic shrubland. Viability, germination speed, electrolyte leakage and indicators of the redox balance including glutathione content, glutathione half-cell reduction potential (EGSSG/2GSH) and malondialdehyde (MDA), oxidized protein content, together with water-soluble antioxidant enzyme activity were assessed. Over a period of two years of storage, viability was maintained when seeds were stored ex situ at 7–9% water content compared to seeds buried in the soil. A second burial experiment showed that seeds of E. chiotilla maintained viability during a year of storage that included a rainy season followed by a dry season. Thereafter, they died rapidly during the second rainy season. In contrast, those of S. pruinosus started to lose viability after 6 months of burial at the end of the rainy season and were mostly dead at the end of the dry season. This difference in persistence between species was related to a difference in the glutathione content and antioxidant enzyme activities. In both storage experiments, the loss of viability of both species was associated to a EGSSG/2GSH shift to a more oxidative state during burial. Yet, contents in MDA and oxidized soluble proteins were not related to redox imbalance and loss of viability, indicating that these compounds are not good markers of oxidative stress in cacti seeds during storage.

Characterization of the damage and its effect on the production of pitayas Stenocereus pruinosus and S. stellatus under different forms of management in Central Mexico

The use of several columnar cacti stretches back several thousand years and is still going at the present. In many of them, their populations within their range of distribution, are subject to three forms of management, including wild, in situ, and cultivated, each of one exposed to different types of damage, biological or physical. This study attempted to characterize the types of damage affecting pitayas (Stenocereus pruinosus and S. stellatus) in central and southern Mexico, and to analyze the relationship between some types of damage under different forms of management, and its effect on reproductive success. The two species were sampled in three populations with different forms of management. The branches (167-180) were selected and measured the amount of damage, characterized the types of damage, and a percentage of the total damage together with the number of fruits that were produced throughout their annual fruiting season were estimated. A x2 test was used to determine the variations in the characterized damage, and the effects of the damage on fruit production in populations with different forms of management was assessed using linear regressions. The eight different types of damage were listed, its frequency, and the effect of damage on fruit production varies in populations. Depending on human management, populations managed demonstrate acceptance of some types of damage by pitaya farmers: bird nests and external black scar, which do not affect the production of fruits; and reduction of others, branch rot and ant herbivory, the latter of which does affect the production of fruits. The fisheye disease, anthropogenic, gray scab and sooty mold and branch rot damage should be addressed in plant health activities in all populations, and the exchange of knowledge with pitaya farmers should be developed to propose measures to attend to these damages. This will support the sustainable use of the species.

Microencapsulates of Stenocereus pruinosus Fermented Juice and Their Bioactive Compounds Using Maltodextrin, Gum Arabic, and Mesquite Gum as Carrier Agents

Pitaya (Stenocereus pruinosus) is a Mexican endemic and highly nutritive fruit, but it is very perishable. Juice contains high amounts of beneficial compounds, especially betalains; however, the viscosity, due to the mucilage, limits its use as pigment in foods. In order to obtain the pitaya pigments to be encapsulated, a simplex-lattice-design was used. Pitaya fermented juices were mixed with mesquite gum (MG), gum arabic (GA), maltodextrin (MDX) or their combinations (5% w/v) and then encapsulated by spray drying at an inner temperature of 160℃. Microcapsules were analyzed in color, bioactive compounds and some physicochemical characteristics. The results showed that three single agents and their combinations (binary and ternary) allowed the obtention of powders. The use of the simplex lattice design revealed the differences in the combination of carrier agents for encapsulation. All yields varied in the range of 64-84%. All powders had moisture content below 6% and water activity around 0.208. Powders showed a pale-red color (Hue and Chroma around 16 and 32, respectively). Powders with MG and GA had the highest red index values. The MG-GA combination retained the higher amount of betalains (3.28± 0.09 mg of total betalains/g powder, particularly betaxanthins). The phenolic compounds content of powders ranged from 8.01-10.77 mg Gallic acid equivalents/g powder and a maximum antioxidant activity of 15.05 mg Trolox equivalents/g powder, particularly the ternary blend (MG-GA-MDX). The antioxidant activity was dominated by other phenolic compounds rather than betalains. Microencapsulated pigments from red pitaya could be used as natural colorants in the food industry. However, further studies should be performed to estimate the potential use of powders as colorants in food systems.

Biofunctional properties of the bioactive peptide from protein isolates of jiotilla (Escontria chiotilla) and pitaya (Stenocereus pruinosus) seeds

In recent years, there has been considerable interest in bioactive peptides derived from food proteins, which might benefit human health. Pitaya and jiotilla are fruits with demonstrated biological functions in its stem, peel, and pulp. However, no studies have been conducted to evaluate the peptides. The aim of this study was to determine biofunctional properties (antioxidant, antihypertensive, and antidiabetic activities) of peptides from cacti seed protein. Antioxidant activity by ABTS, ACE inhibition activity, and α-amylase inhibition activity was carried out in the peptides. Based on the obtained results, hydrolyzed total protein isolate of pitaya showed high antioxidant activity (1328.40 ± 63.50 μM Trolox equivalents/mg protein). Moreover, hydrolyzed glutelin fraction of pitaya has a high α-amylase inhibition activity (76.74 ± 2.15%). On the other hand, hydrolyzed total protein isolate of jiotilla had a good ACE inhibition activity (47.64 ± 3.16). These results demonstrated that pitaya and jiotilla seeds protein hydrolysates had excellent in vitro nutraceutical potential.

Evaluation of three methods for betanin quantification in fruits from cacti

In México, production of cacti fruits has increased. These fruits have high concentration of betalains (pigments), and market has increased interest in food with natural ingredients. In the near future, a sustainable method for betanin quantification in cacti fruits for rural communities will be necessary. Betanin in pulp of garambullo (Myrtillocactus geometrizan), chico fruit (Pachycereus weber), jiotilla (Escontria chiotilla) and pitaya de mayo (Stenocereus pruinosus) were quantified using three different analytical methods. The techniques were of Spectrophotometry UV-Vis (SCC), High-Performance Liquid Chromatography (HPLC) and Spectrophotometry technique using Molar Extinction Coefficient (SEC). The accuracy and intermediate precision were evaluated in SEC, SCC, and HPLC with the four cacti´s fruit. The means betanin concentration in the pulps were 0.68±0.05 (mg/g dry weight) garambullo, 1.28±0.06 (mg/g dry weight) chico fruit, 1.84±0.34 jiotilla and 2.0±0.25 pitaya de mayo (mg/g dry weight). The concentration of betanin in garambullo pulp measured by the three methods did not differ significantly (P >0.05). In this case, SEC method represents the best option to reduce costs, time and solvents in this way this method is aligned with green chemistry. In the three methods, coefficient of variation between measurements obtained are below 15%.•Robust method to quantify betanin and evaluate intermediate precision•Validation parameters such as LOD, LOQ, accuracy, intermediate precision, and HorRat were considered•The developed method enriches the valorization of underutilized national agricultural sources of Mexico

Absence of Fruit Mexican Fly (<i>Anastrepha ludens</i>) in Pitaya de Mayo (<i>Stenocereus pruinosus</i>)

Pitaya de mayo (Stenocereus pruinosus) exportation is considered feasible especially to the United States of America (USA) using the adequate preservation and transportation techniques. One of the exportation requirements is that pitayas, as well as any other tropical fruits, have to be free from Mexican fruit fly contamination and certified by the Food National Sanitary, Iniquity, and Quality Service. This review proved that this fruit is not attacked by the Mexican fruit fly A. ludens or any other Anastrepha species. The fruit fly may be found in some States of Mexican Republic such as some tropical regions but not in the semi-arid regions where cacti fruits are grown.

Shelf life of pitaya [ Stenocereus pruinosus Otto ex Pfeiff.) Buxb.] fruit affected by temperature and guar gum, beeswax, oleic acid, and thyme essential oil coatings

Pitaya [Stenocereus pruinosus Otto ex Pfeiff.) Buxb.] produces fruit with high commercialization potential, but its shelf life is limited to few days. The objective of this study was to apply biopolymeric coatings to extend the shelf life of pitaya fruits at 25 °C and under refrigeration at 12 °C. The following variables were handled at each temperature: fruits without any treatment (Control), fruits coated with 1,000 ppm emulsion of thyme essential oil, and fruits coated with 1% emulsion of guar gum, 7.5% beeswax, and 7.5% oleic acid, without essential oil, and with 1,000 ppm of thyme essential oil. Shelf life was 6 d at 25 °C, without the beneficial effect of coatings, but increased to 15 d with refrigeration and coatings based on guar gum, beeswax, and oleic acid, since fungal growth was delayed, and weight loss was reduced. This allowed fresh appearance without significant modification of color, firmness, pH, total soluble solids, titratable acidity, contents of soluble phenols and betalains, and antioxidant capacity.

Amyloid β aggregation inhibitory activity of triterpene saponins from the cactus Stenocereus pruinosus.

Six new triterpene saponins (1–5,7) and 3 known saponins (6,8,9) were isolated from MeOH extracts of the cactus Stenocereus pruinosus. The structures of the isolated saponins were elucidated using MS, IR, and comprehensive NMR measurements. To develop drugs for treating Alzheimer’s disease (AD) on the basis of the amyloid cascade hypothesis, the isolated saponins were evaluated for inhibition of BACE1 activity and amyloid beta (Aβ) aggregation using thioflavin-T assay, and triterpenes as an aglycone moiety and an alkaline hydrolysate of the saponins were also evaluated. One saponin, stenoside A (7), exhibited inhibitory activity related to Aβ aggregation and its degree of Aβ aggregation was 40.6% at 100 μM.Graphic abstract Electronic supplementary materialThe online version of this article (10.1007/s11418-020-01463-0) contains supplementary material, which is available to authorized users.

Low-sugar content betaxanthins extracts from yellow pitaya (Stenocereus pruinosus)

Consumer preferences, and potential health risks associated with the consumption of synthetic food colors, explain the commercial interest in alternatives from natural sources. Betaxanthins from cactus fruit have been used to color food products, but sugars are not usually removed from these extracts leading to processing and formulation challenges. In this study, low-sugar betaxanthin preparations were obtained from a crude yellow pitaya Stenocereus pruinosus extract using aqueous two-phase systems (ATPS). This study focuses on the effect of the salts and polymer choice (polyethylene glycol (MW 1000; PEG1000) or polyalkylene glycol copolymer (MW 3930, UCON), tie line length (TLL), phase volume ratio (Vr), and crude extract percentage on the partitioning of betaxanthins and sugars in the crude extract. PEG1000-phosphates were more suitable than UCON-salts for the extraction of betaxanthin. Multivariate analysis of variance (MANOVA, α = 0.05) showed that TLL, Vr and crude extract concentration effects were statistically significant (P < 0.05). The correlation with Vr, crude extract concentration, and TLL was determined by multiple linear regression. The desirability function was used to identify an ATPS (TLL = 37.7 %, Vr = 0.3, and 7 % crude extract) yielding a top phase with minimum total sugar (2.8 %) and maximum betaxanthin content (52.3 %).

Ozone-high hydrostatic pressure synergy for the stabilization of refrigerated pitaya (Stenocereus pruinosus) juice

Abstract The synergistic effect of ozone (24 mg/O3/L/min) and high hydrostatic pressure (HHP, 179–321 MPa) combination was evaluated with regard to individual effects of these over the microbial population in pitaya juice by using a response surface methodology and a repeated measures design with Tukey test. Treatment with 300 MPa/5 min reduced 6.89-log10 and 0.89-log10 CFU/mL of Saccharomyces cerevisiae and Listeria innocua population, respectively; and treatment with 9.6 min of ozonation time reduced 0.47-log10 and 2.51-log10 CFU/mL of S. cerevisiae and L. innocua population respectively; however, L. innocua was reduced 5.1-log10 CFU/mL with exposure to ozone for 7 min followed by 316 MPa/5 min. Likewise, these treatment conditions kept native microbiota of the juice at non-detectable levels and achieved the highest sensory preference (79%) as compared to untreated juice at 30 d (5 ± 2 °C). Ozone-HHP reduced bacterial counts suggesting a microbiologically safe pitaya juice, contrary to what was obtained with individual application of these technologies.

Cross-Linking Chitosan into Hydroxypropylmethylcellulose for the Preparation of Neem Oil Coating for Postharvest Storage of Pitaya (Stenocereus pruinosus).

The market trend for pitaya is increasing, although the preservation of the quality of this fruit after the harvest is challenging due to microbial decay, dehydration, and oxidation. In this work, the application of antimicrobial chitosan-based coatings achieved successful postharvest preservation of pitaya (Stenocereus pruinosus) during storage at 10 ± 2 °C with a relative humidity of 80 ± 5%. The solution of cross-linked chitosan with hydroxypropylmethylcellulose with entrapped Neem oil (16 g·L−1) displayed the best postharvest fruit characteristics. The reduction of physiological weight loss and fungal contamination, with an increased redness index and release of azadirachtin from the microencapsulated oil, resulted in up to a 15 day shelf life for this fruit. This postharvest procedure has the potential to increase commercial exploitation of fresh pitaya, owing to its good taste and high content of antioxidants.

Flower-Inhabiting Sap Beetles (Coleoptera: Nitidulidae: Carpophilinae) in Guatemala

We report three species of Nitops Murray (Nitidulidae: Carpophilinae) sampled from fallen and freshly withered flowers of the columnar cactus Stenocereus pruinosus (Otto) Buxb. (Cactaceae) in a subtropical dry forest in Guatemala. Our observations suggest that adults of these species oviposit inside the flowers during or prior to the blooming period, and the larvae feed on floral tissues. Larval feeding likely occurs without damaging floral ovaries due to flower abscission.

High hydrostatic pressure inactivation and recovery study of Listeria innocua and Saccharomyces cerevisiae in pitaya (Stenocereus pruinosus) juice

Abstract The high hydrostatic pressure (HHP) inactivation of Listeria innocua and Saccharomyces cerevisiae was investigated in pitaya juice subsequently stored 15 d under refrigeration to assess recovery. Juice inoculated to 7.6 ± 0.4 or 7.3 ± 0.3 log10 (CFU mL−1) of L. innocua or S. cerevisiae, respectively, was treated at 400 to 600 MPa for 7.6 to 15 min (Tinitial = 19.5 ± 2.8 °C and Tmax = 34.6 ± 2.0 °C) following a Response Surface Design. Come-up time (CUT), defined as pressure release 1 s after reaching pressure set-point, was also evaluated. After a 400 MPa CUT treatment, no viable S. cerevisiae survivors were observed. Treatments at 550 and 600 MPa for 16 and 12 min, respectively, achieved L. innocua reductions exceeding 5-log10. No viable S. cerevisiae were observed when treated juice was stored at 4 ± 1 °C for up to 15 d. HHP appears a viable nonthermal alternative to produce a microbiologically safe and stable pitaya juice.

Encapsulation and pigmenting potential of betalains of pitaya (Stenocereus pruinosus) fruit.

Betalains of pitaya (Stenocereus pruinosus) fruit can be used as natural pigment, but they are susceptible to deterioration by temperature, pH, and presence of sugars. In this work, a refined extract (Er) of betalains was obtained through aqueous two-phase extraction, which reduced significantly sugar and mucilage contents. In order to favor stability, the encapsulation of the refined extract was evaluated, with native potato starch that was modified through phosphorylation or succinylation and reactive extrusion. Starches were evaluated in terms of degree of substitution, Fourier transform infrared spectroscopy, scanning electron microscopy, and viscous behavior. Microcapsules were formed by spray drying and their stability was evaluated at 40°C for 39days and by using them as pigmenting agent of yogurt at 4°C during 32days. The behavior of modified starches during encapsulation was superior to that of commercial N-Lok® starch. Microcapsules based on modified starches showed better pigmenting potential and higher stability than Er and microcapsules based on N-Lok® starch. The separation of betalains from pitaya fruit may be a good alternative for adding value to this plant genetic resource.

Betaxanthins and antioxidant capacity in Stenocereus pruinosus: Stability and use in food

Betalains are important pigments for the food, pharmaceutical, and cosmetics industry. In the yellow Stenocereus pruinosus fruits (pitayas), total betalain concentration, Folin-Ciocalteu reduction capacity, and antiradical capacity per dry weight were 2345.9μgg−1, 7.3mg gallic acid equivalentsg−1, and 48.8μmol Trolox equivalentg−1, respectively. The stability of betaxanthins, which represent 89% of total betalains in yellow pitayas, was evaluated over a range of pH, temperature, as well as in the presence of food additives. Maximum stability was observed at pH6.6, and addition of ascorbic acid increased the half-life 1.8 times. Thermal stability at pH6.48±0.05 was also evaluated from 50°C to 80°C, over which the activation energy for betaxanthin degradation was determined to be 66.2kJmol−1. Model gelatin gummies and beverages were then prepared with pitaya juice or pulp, and pigment retention and color parameters were investigated during storage under various conditions. To match the yellow color of commercial products, gummies were supplemented with 4.6% w/w juice or pulp, and beverages were supplemented with 5% w/v juice, achieving H° values of 69.0–86.2° and 64.6–87.1°, respectively. Results indicate that betaxanthins were more stable in gummies than in beverages, and that pigment retention increased when products were stored in the dark or at low temperatures. Also, different changes in color during storage were observed between gummies and beverages.

Post-harvest Preservation of Cactus Fruits Produced in Semidesertic Areas of Oaxaca by Biopolymer Coatings

AbstractThe pitaya (Stenocereus pruinosus) and sweet xoconostle (Stenocereus stellatus) are Cactaceae fruits with local distribution, due to their perishability and microbial decay with postharvest life from 3 to 5 days. Thus, the objective of this research was to apply chitosan based coatings: commercial chitosan (CQ), chitosan produced by biological-chemical method (Q) and Q grafted to hydroxypropylmethylcellulose in an emulsion with entrapment neem oil (N) (NMQ-g-H). Application in field was carried out in Santa Gertrudis Cosoltepec, in the Mixteca area of Oaxaca, which is a deforested region with eroded soil. QC, Q and NMQ-g-H at 10±5°C and 75±5% relative humidity extended the postharvest life of fruits by 15 days. Q was obtained by thermochemical heterogeneous deacetylation from chitin extracted from a lactic fermentation of shrimp wastes, therefore there is an additional benefit, due to the decrease of wastes produced in coastal area by obtaining value-added products that served as coatings for prolong postharvest life of fruits produced in Mixteca Region of Oaxaca.

Effects of natural and artificial selection on survival of columnar cacti seedlings: the role of adaptation to xeric and mesic environments.

Escontria chiotilla, Polaskia chichipe, and Stenocereus pruinosus are species of Mexican columnar cacti that are economically important because of their edible fruits. These species are managed by gathering fruits from the wild, silvicultural management in agroforestry systems, and cultivation in home gardens. Previous studies reported that artificial selection favored individuals that produced larger fruits, which indirectly led to the production of larger seeds and seedlings, with possible effects on survival. We hypothesized that seedlings from managed populations would be larger but more susceptible to xeric conditions than those from wild populations. We evaluated the effects of artificial and natural selection on seedling survival of the three species in wild and managed populations, which were managed with low and high intensity, respectively. We tested seedling performance in gradients of shade (0, 40, and 80%) and humidity (low and high). A GLM of seedling survival showed significant differences among species, shade, and humidity treatments, with each species having environmental requirements associated with their particular adaptations. High humidity decreased seedling survival of all species, and high solar radiation decreased survival of S. pruinosus and P. chichipe. The effect of management type was significant only in S. pruinosus. Significant differences in the initial growth of seedlings among species were detected with ANOVA. In optimal conditions, the hypocotyl and the cotyledons decreased in size and the epicotyl grew, whereas under stress, these structures remained unchanged. The optimum conditions of shade and humidity varied among species and management types. The seedlings of S. pruinosus were the largest and the most susceptible, but in all species, seedlings from managed populations were more susceptible to environmental conditions. Thus, artificial selection influenced the susceptibility of these cacti to xeric environments.

Physical, Chemical, and Antioxidant Activity Characterization of Pitaya (Stenocereus pruinosus) Fruits

Fruits with red and orange flesh of the columnar cactus pitaya (Stenocereus pruinosus) were studied to evaluate physical characteristics, total soluble solids, betalains and soluble phenols content, and antioxidant activity. Fruits had, in average, weight of 179.0g, 9.8 °Brix, 9.4% carbohydrates, 1.25% protein, 0.11% ethereal extract, 0.60% crude fiber, and 0.62% ash. Also, fruits resulted rich in Fe (22.8-27.8mg/kg). Hue angle and contents of betacyanins, betaxanthins (μg/g dry sample), and total soluble phenols (mg GAE/g fresh sample) were 19.8°, 2860.0, 3210.0, and 1.6 in the red material, and 28.9°, 470.0, 2670.0, and 1.2, respectively, in the orange fruit. The antioxidant capacity was higher in the red material, since the ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)) technique reported 1090.6 and 735.4μmol of Trolox equivalents/g fresh flesh in red and orange fruits, respectively, while the oxygen radical absorbance capacity (ORAC) assay reported 7.84 and 5.16μmol of Trolox equivalents/g fresh flesh, respectively. The chromatographic profile showed five betalains in red fruits, but only four of them were observed in those orange fleshed.

Frugivory diet of the lesser long-nosed bat (Leptonycteris yerbabuenae), in the Tehuacán Valley of Central Mexico

Resumen The lesser long nosed bat Leptonycteris yerbabuenae (Phyllostomidae: Glossophaginae), is a migratory species highly specialized for nectar and pollen consumption. Although they can consume fruits of columnar cactus (Family Cactaceae, tribes Pachicereeae and Cereeae), this habit has not been studied sufficiently to know the importance of this frugivory. Available information shows that this bat can consume actively fruit of columnar cactus, and indeed seven of these fruits have been cited as part of their diet in North America. Nevertheless, it is unknown whether other cactus fruits are edible for them. In Tehuacan Valley, located in south central Mexico L. yerababuenae co-occur with 21 species of cactus that produce sweet, juicy and soft fruits, with small seeds appropriate to be eaten by the long-nosed bat. We conducted one study to determine the identity of cacti fruits eaten by L. yerababuenae, through the identification of seeds deposited as guano and obtained in the Obispo cave (municipality of Santiago Chazumba, Oaxaca). Seeds of all species of cactus that inhabit Tehuacan Valley were identificated in guano. We recollected 31,895 seeds inside the cave, but more than the 84% corresponded to four species of cacti seeds: Isolatocereus dumortieri, Stenocereus pruinosus, Stenocereus stellatus and Neobuxbaumia macrocephala. The species Escontria chiotilla, Pachicereus hollianus, Hilocereus undatus, Pachicereus fulviceps and Stenocereus treleasei, were rare and they had less than 20 seeds in the sample. So results obtained suggest that L. yerababuenae, may eat fruits as an important part of its diet, and probably serves as an important disperser of columnar cactus in dry environments of South Central Mexico.

Landscape management and domestication of Stenocereus pruinosus (Cactaceae) in the Tehuacán Valley: human guided selection and gene flow.

BackgroundUse of plant resources and ecosystems practiced by indigenous peoples of Mesoamerica commonly involves domestication of plant populations and landscapes. Our study analyzed interactions of coexisting wild and managed populations of the pitaya Stenocereus pruinosus, a columnar cactus used for its edible fruit occurring in natural forests, silviculturally managed in milpa agroforestry systems, and agriculturally managed in homegardens of the Tehuacán Valley, Mexico. We aimed at analyzing criteria of artificial selection and their consequences on phenotypic diversity and differentiation, as well as documenting management of propagules at landscape level and their possible contribution to gene flow among populations.MethodsSemi-structured interviews were conducted to 83 households of the region to document perception of variation, criteria of artificial selection, and patterns of moving propagules among wild and managed populations. Morphological variation of trees from nine wild, silviculturally and agriculturally managed populations was analyzed for 37 characters through univariate and multivariate statistical methods. In addition, indexes of morphological diversity (MD) per population and phenotypic differentiation (PD) among populations were calculated using character states and frequencies.ResultsPeople recognized 15 pitaya varieties based on their pulp color, fruit size, form, flavor, and thorniness. On average, in wild populations we recorded one variety per population, in silviculturally managed populations 1.58 ± 0.77 varieties per parcel, and in agriculturally managed populations 2.19 ± 1.12 varieties per homegarden. Farmers select in favor of sweet flavor (71% of households interviewed) and pulp color (46%) mainly red, orange and yellow. Artificial selection is practiced in homegardens and 65% of people interviewed also do it in agroforestry systems. People obtain fruit and branches from different population types and move propagules from one another. Multivariate analyses showed morphological differentiation of wild and agriculturally managed populations, mainly due to differences in reproductive characters; however, the phenotypic differentiation indexes were relatively low among all populations studied. Morphological diversity of S. pruinosus (average MD = 0.600) is higher than in other columnar cacti species previously analyzed.ConclusionsArtificial selection in favor of high quality fruit promotes morphological variation and divergence because of the continual replacement of plant material propagated and introduction of propagules from other villages and regions. This process is counteracted by high gene flow influenced by natural factors (pollinators and seed dispersers) but also by human management (movement of propagules among populations), all of which determines relatively low phenotypic differentiation among populations. Conservation of genetic resources of S. pruinosus should be based on the traditional forms of germplasm management by local people.