Pachycereus Pecten-aboriginum Research Articles

Fruit Juices of Etcho (Pachycereus pecten-aboriginum) and Giant Cardon (Pachycereus pringlei) are Sources of Health-Promoting Ingredients with Potential Anticancer Properties.

Mexico is one of the main diversification centers of cacti in the world, with more than 500 endemic species, most of which remain nutritionally and functionally uncharacterized. The columnar cacti of the genus Pachycereus comprise five underutilized endemic Mexican species, whose nutraceutical properties have only been studied in the P. weberi species. Therefore, this study aimed to evaluate the nutritional quality and bioactive properties of etcho (P. pecten-aboriginum) and giant cardon (P. pringlei) fruit. The physical, chemical, and nutritional composition of etcho and giant cardon fruits were characterized, as well as the profile and content of bioactive compounds, antioxidant activity (ABTS•+ and DPPH•), and antiproliferative capacity in cervical (HeLa) and breast cancer (MDA-MB-231, MCF-7, and T-47D) cell lines. Our results suggest that etcho and giant cardon fruits are rich sources of essential nutrients and bioactive phytochemicals (including K, Mg, P, dietary fiber, polyphenolic compounds, vitamin C, betalains, and myo-inositol) with antioxidant and anticancer potential by inhibiting the proliferation of all evaluated cell lines with IC50 values in the range of 198 to 287µg of gallic acid equivalents/mL. Therefore, etcho and giant cardon fruits could be used for nutraceutical purposes, and their consumption could promote health benefits.

Composición y estructura florística de una porción de selva baja caducifolia en Tecomán, Colima, México

A floristic list and an estimate of the community descriptors of a voluntary conservation area located in Tecoman, Colima, are presented to contribute to the knowledge of the vegetation of the dry forests of the Mexican Pacific. The floristic list was built with transects done between 2017-2019. For the community descriptors, the study area was divided into three zones according to their time without management: east slope (LE; without management), central area (AC; 16 years), and west plain (LO; five years); two transects were established in each zone and were sampled during the 2018 dry season. Community and structural descriptors were estimated, and comparisons between the transects were made using an analysis of similarities (ANOSIM); vegetation profiles were based on a transect per area. We found 147 species in 52 families; the richest in species were Fabaceae and Malvaceae with 19 and 14 species, respectively. The descriptors show that the LE is the most diverse (Ds = 0.94 and H’ = 3.00) and equitable (J = 0.93). The most important species were Pachycereus pecten-aboriginum (8.81%) in LE, Acrostichum danaeifolium (14.59%) in AC, and Poaceae family in LO (24.96%). The comparison between the areas suggests that there is an important turnover of species (60% – 80% of the species) and the ANOSIM suggests that there are qualitative differences between them (R = 1.00 and P = 0.07), so the structure and composition of the areas seem to reflect a succession in time and space: LE > AC > LO.

Phytotoxic and dissuasive activity of Chihuahua desert plants

With the purpose of finding plant compounds with the potential use as herbicides and insecticides, a research was realized with the objective of evaluate the phytotoxic and dissuasive activity of four Chihuahua desert plants. The phytotoxic activity evaluation was tested on Lactuca sativa and Lolium perenne, while the dissuasive activity was realized on three species of phytophagous insects: Myzus persicae, Rhopalosiphum padi and Spodoptera littoralis. Raw extracts were used, the solvents hexane, methanol and ethanol of different plants’ organs (root, steam, leaf and flower) of four species: Fouquieria splendens (ocotillo), Larrea tridentate (governor), Astragalus mollissimus (wild grass) and Pachycereus pecten-aboriginum (echo), by the establishment of in vitro bioassays at a concentration of 10 mg/ml extract/solvent. In the toxicity bioassay, the percentage of germination, root and leaf length were measured. The results showed that the leaf extract of L. tridentata had phytotoxic activity for L. sativa, while for L. perenne the phytotoxicity was observed within the ocotillo, governor and echo extracts. In the dissuasive bioassay, each treatment had 20 repetitions with 10 adult insects per repetition. The methanolic extracts of F. splendens leaf and root, ethanolic extract of A. mollisimus sheet and the ethanolic extract of P. pecten-aboriginum stems showed moderate dissuasive response of feeding against M. persicae, presenting a settlement inhibition index of 53.53, 54.35, 60.00 and 48.84% respectively. Nevertheless, the results indicated that none of the 10 extracts tested on S. littoralis showed significant dissuasive properties for this Lepidoptera, while for R. padi all the tested extracts presented dissuasive properties. The treatments of the four vegetable species evaluated showed defensive or dissuasive properties of moderate to strong feeding against the insects M. persicae and R. padi, presenting interesting potential for being used as insecticides, while the tested extracts that presented phytotoxicity for both lettuce and ryegrass present possibilities for the realization of herbicides.

Wood density, deposits and mineral inclusions of successional tropical dry forest species

Wood water content, wood dry mass fraction, wood deposits and mineral inclusions separately affect wood mechanical properties, as well as plant survival and growth rates. Tree species occurring in recovering vegetation from deforestation face water stress, which is a particularly strong environmental filter in tropical dry forest regions. In this study, we analyze wood density and its associated variables of tree species present in early and late successional communities. We assessed and compared their wood density, wood water content, wood dry mass fraction, as well as wood cellular deposits, secretory elements and mineral inclusions which were described through anatomical sections. Wood density ranged from 0.10 g/cm3 (Jacaratia mexicana in late successional community) to 0.92 g/cm3 (Lysiloma divaricatum in early successional community). Successional species showed low intraspecific variability, despite large differences in the environmental conditions in the communities where they grow. Species with high wood water content were restricted to late successional communities, and pioneers showed higher wood density than non-pioneer species, which supports the linkage between high wood density and harsh environmental filtering through hydraulic safety. Wood density did not differ between columnar cacti (Pachycereus pecten-aboriginum and Pilosocereus collinsii) and tree species such as Bursera simaruba. Starch, tannins and crystals were abundant in most successional species and some species had gums; these deposits could potentially influence wood density and hydraulic, defense and storage plant functions. Our results suggest that modifications in the life cycle of successional tropical dry forest tree species due to anthropogenic activities may not be an important source of wood density variation.

The effect of treefall gaps on the understorey structure and composition of the tropical dry forest of Nizanda, Oaxaca, Mexico: implications for forest regeneration

Abstract:The role of canopy gaps in tropical dry forest (TDF) dynamics remains unclear. Here, 75 canopy gaps, mostly formed by the fall of Bursera spp. and Pachycereus pecten-aboriginum individuals, are described, and their potential consequences for forest regeneration are analysed in a Mexican TDF. In 50 randomly selected gaps, understorey vegetation was sampled with a paired design (inside and outside gaps) and by distinguishing two plant height categories. In total, 1940 plants were recorded (63% in gaps and 37% in non-gap plots). Community attributes (density, community cover, taxonomic richness and Shannon diversity) were significantly higher for both height categories in gap plots. Conversely, neither an NMDS ordination nor a multinomial classification of 187 species by habitat affinities revealed floristic segregation between gaps and non-gaps; almost all species were classified as habitat generalists, with only a few opportunistic forbs (but no single tree species) being classified as gap specialists. The most important effects of gap formation are significant increases in plant abundance and species richness, but not a different species composition. Against earlier views that gap-phase dynamics is inconsequential for TDF dynamics, these results suggest a more active, albeit modest, role of treefall gaps in TDF, through promoting an abundant establishment.

Salinity effects on germination and seedlings biomass of Pachycereus pecten-aboriginum: an endangered species

Cacti are particularly sensitive to habitat disturbance since they have slow growth and a longlife cycle. Their development and establishment depend on several factors, includingenvironmental requirements for germination and establishment of seedlings. Two of the mostinfluential factors are soil and water salinity. The objective of this study was to quantify seedsgermination and seedling biomass production of the Aborigine’s comb cactus (Pachyceruspecten-aboriginum) in salt stress using sodium chloride (NaCl) as the main salt source. Theexperiment was arranged in a completely randomized design using six salt levels (0.11, 2.03,4.00, 6.03, 8.03 and 10.07 dS m-1) with five replicates of 20 seeds each one. The seeds werecollected in a wild population of P. pecten-aboriginum in Ejido Álvaro Obregón, BajaCalifornia Sur, Mexico in June 2011. The results showed that germination and seedlingbiomass were significantly affected by salt stress, which was higher at 2.03 and 0.11 dS m-1,followed by 6.03 and 4.00 dS m-1, lower at 8.03 dS m-1, and no growth at 10.07 dS m-1. It isconcluded that saline levels using sodium chloride as the main source of salt, affect seedgermination and seedling biomass production of P. pecten-aboriginum significantly.

Effects of land conversion on the regeneration of Pachycereus pecten-aboriginum and its consequences on the population dynamics in northwestern Mexico

Pachycereus pecten-aboriginum is a columnar cactus currently threatened by the conversion of natural vegetation to buffelgrass pasture ( Pennisetum ciliare) in Sonora, Mexico. However, knowledge about its population dynamics is extremely poor, particularly in response to disturbance caused by pasture conversion. We set up experiments to evaluate seed removal, germination, seedling survival and compared demographic patterns on permanent plots from natural vegetation and pasture. Our experiments on regeneration show that seedlings were unable to establish in pasture because of high levels of mortality due to soil drying and cattle trampling. The population growth rate ( λ) was 1.060 and 1.086 for the 2006–2007 and 2007–2008 periods, respectively, in the native thornscrub vegetation. The slight increase in λ in 2007–2008 was a result of increased fecundity and seedling survival. The highest elasticity values correspond to the survival of large/old individuals. Using the average of both matrices, we obtained a mean matrix to perform numerical analyses simulating demographic variation to project the population behavior under buffelgrass pasture conditions. The numerical simulations suggest a decreasing population only when adult survival probabilities were affected. Given these limitations for population growth, our data suggest that adult populations that persist on pastures will be driven into local extinction.

Diet and Cranial Morphology ofMusonycteris harrisoni, a Highly Specialized Nectar-Feeding Bat in Western Mexico

We studied the morphology and diet of Musonycteris harrisoni, an endangered nectar-feeding bat endemic to western Mexico, and explored potential reasons for the cranial specialization of this extraordinarily long-snouted bat. We achieved 28 captures in the wet season and 30 in the dry season, which represents the largest data set in existence for this rare species. We took morphological data and collected pollen from the bats' pelage. Diet analysis revealed the genera Cleome, Pseudobombax, Crataeva, Agave, Helicteres, and the columnar cactus Pachycereus pecten-aboriginum as main food plants. We found no indication for a tight relationship between M. harrisoni and long-tubed flowers that would obligatorily require a long rostrum for exploitation, with the possible exception of the columnar cactus. However, because cacti are common food plants for many less-specialized nectar-feeding bats, the extraordinarily long rostrum might permit M. harrisoni to use the same abundant plant species as larger species while maintaining a smaller body size, therefore having lower absolute energy requirements. This in turn could facilitate a resident lifestyle in a habitat with annual resource bottlenecks. Males have significantly longer snouts (approximately 9%) than females, suggesting that rostrum length also might be influenced by intraspecific interactions or restrictions. Our favored explanation is that the rostrum length of females may be limited by stability issues, because calcium mobilization during pregnancy and lactation can considerably weaken bone structure.

Influence of buffelgrass pasture conversion on the regeneration and reproduction of the columnar cactus, Pachycereus pecten-aboriginum, in northwestern Mexico

Buffelgrass ( Pennisetum ciliare) has been planted in large areas of desert and thornscrub of northwestern Mexico in order to increase forage production. However, no previous study has documented the influence of land conversion on the native species that persist on buffelgrass pastures. In this paper, we describe the influence of buffelgrass conversion on the regeneration and reproduction of the columnar cactus, Pachycereus pecten-aboriginum, in the state of Sonora. We selected three different pastures of different age and adjacent undisturbed thornscrub where we estimated abundance and population structure of this cactus. During the flowering season, we estimated several reproductive parameters. We also set up an experiment to explore whether seedlings are able to establish in the buffelgrass pasture. Our results indicate that land conversion has no significant effect on plant abundance, but a major effect on size distribution. For most reproductive parameters, no statistically significant differences were detected between thornscrub and pastures. Seedlings were able to establish only on thornscrub, as all seedlings that emerged in pasture died within 1 year. Land conversion has apparently a minor effect on plant reproduction, but a significant effect on the regeneration of this columnar cactus. Our data suggest that adult populations that persist on pastures are unable to self-replace and native populations will be driven into local extinction.

Geographic differentiation in the pollination system of the columnar cactus Pachycereus pecten ‐aboriginum

The pollination biology of the cactus Pachycereus pecten-aboriginum was studied in a tropical location in western Mexico (ca. 18° N latitude) to compare with data from a northern population (ca. 28° N latitude). Throughout this range, the nectar-feeding bat Leptonycteris curasoae is resident within the tropics but migratory in its northern range. The hypothesis was tested that if a predictable bat presence has been an important force in the evolution of pollination systems in columnar cacti, P. pecten-aboriginum will have a specialized pollination system within the tropics and a generalized pollination system in northern populations. In both areas, pollination experiments showed that P. pecten-aboriginum has a self-incompatible, hermaphroditic breeding system. In the tropical area, flowers open at night and close early in the morning. Nectar is secreted only during the night, and flowers are exclusively pollinated by three species of nectar-feeding bats, indicating a specialized pollination system. In contrast, anthesis and nectar secretion in northern populations occur during the night and day, allowing visitation and effective pollination by both nocturnal and diurnal pollinators. This study provides evidence of divergence mediated by pollinator predictability (resident vs. migrant), through shifts from short to long anthesis and nectar production periods from southern to northern populations.

Pollination biology of the columnar cactus Pachycereus pecten-aboriginum in north-western México

Columnar cacti in tropical deserts depend on nectar-feeding bats for their reproduction while species from extra-tropical deserts show a relatively generalized pollination system with both nocturnal and diurnal pollinators. Pachycereus pecten-aboriginum is a columnar cactus with a broad distribution along the Pacific coast of México, from Oaxaca to Sonora. Along its distribution, the nectar-feeding bat, Leptonycteris curasoae, changes from resident within the tropics to migratory in the Sonoran desert. If bat unpredictability has been an important force in the evolution of pollination systems in columnar cacti, P. pecten-aboriginum is expected to show a relatively generalized system in northern populations. We studied the pollination biology of P. pecten-aboriginum in two northern populations in the state of Sonora. Hand pollination experiments showed that this species has a self-incompatible, hermaphroditic breeding system. Although flowers open at night, they remain open and continue secreting nectar during the morning, allowing visitation by both nocturnal and diurnal pollinators. One population showed evidence of strong pollinator limitation while the results from both populations indicated that diurnal pollinators are more important than nocturnal pollinators. These results are discussed in terms of specialization vs. generalization in the pollination biology of columnar cacti in tropical and extra-tropical deserts.

Proximate Composition, Protein Quality and Oil Composition in Seeds of Columnar Cacti from the Sonoran Desert

Fruits of columnar cacti are an important food resource from the arid lands of México. However, little is known about their nutritional value. In this paper, seeds of five species of columnar cacti from the Sonoran desert were studied to determine their protein and oil composition. The studied species were: Pachycereus pringlei, Pachycereus pecten-aboriginum, Carnegiea gigantea, Stenocereus thurberi and Stenocereus gummosus. Protein content varied from 20.3 to 22.0% among species. These proteins showed a high content of sulfur containing amino acids but were low in lysine. In vitro digestibility ranged from 77 to 86% among species and increased with the thermal treatment. Protein from P. pringlei was assessed in vivo and showed PER values of 2.8% and digestibility of 91.6%. Oil content ranged from 28.4 to 30.7% among species. Most oils showed a high degree of unsaturation. Linoleic (50–53%) and oleic (35–37%) acid were the most important fatty acids present in all oils. The results are compared with other studies on the seeds of columnar cacti. Future studies aimed at evaluating the nutritional value of the fruits are discussed.

Seed Hydration Memory in Sonoran Desert Cacti and Its Ecological Implication

Cactus seeds on the soil surface in the desert are subjected to periods of drought that last for up to a few months, and thus they are typically under discontinuous hydration (or discontinuous dehydration). Apparently, they can tolerate long periods of dehydration after single or multiple hydration events and subsequently germinate in accordance with the previous hydration experience. This was verified in three cactus species from the Sonoran Desert. Seeds of Stenocereus thurberi hydrated for 72 or 80 h followed by a dehydration period lasting for 4, 14, 70, 120 or 181 d germinated 2–3 d earlier and had 1.4–2 times shorter mean germination time (MGT) than untreated seeds. Seeds given shorter hydration periods also began to germinate sooner than the controls. MGT was shorter only when the hydration period was 48 h or longer. Final germination percentages were not affected by these treatments, only the MGT. Except for differences in germination percentages, similar results were found for Pachycereus pecten-aboriginum and Ferocactus peninsulae. When the cycle of 24 h hydration followed by 4 d dehydration was repeated one or two times, the effect was cumulative: MGT was equal to 48 and 72 h hydration, respectively. These results suggest a phenomenon of “seed hydration memory,” the ability of seeds to retain during dehydration periods those physiological changes that result from seed hydration. Thus, treated seeds subsequently germinated earlier then untreated seeds, regardless of the duration of dehydration period. This led to a greater biomass accumulation and thus to higher survival in seedlings from treated than from untreated seeds.

Influence of vesicular-arbuscular mycorrhizae on biomass production by the cactus Pachycereus pecten-aboriginum

This study reports the effect of vesicular-arbuscular mycorrhizal (VAM) fungi on dry matter production by Pachycereus pecten-aboriginum (Engelm.) Britt & Rose, an arborescent cactus of arid and tropical dry forest in Mexico. Seedlings in the presence or absence of VAM fungi were grown in soil between two plates of glass (20 × 30 cm) for 8 months inside growth chambers (30/25° C, 13/11 h day/night and a light intensity of 400 μmol m-2 s-1). VAM seedlings had significantly (P<0.01) higher dry matter production (0.418 versus 0.169 g), root/shoot ratios (0.26 versus 0.14) and specific root length (0.65 versus 1.41 mm mg-1) than non-VAM seedlings, suggesting a more efficient exploitation of soil resources by the VAM cacti. The data point to a role for VAM fungi in the establishment, growth, water relations and nutrition of cacti in the arid tropics.

Distribution and morphology of columnar cacti in tropical deciduous woodland, Jalisco, Mexico

The distribution and branching morphologies of four species of columnar cactus species in tropical deciduous woodland in Jalisco, western Mexico, are examined. Two species, Stenocereus marginatus and especially Pachycereus pecten-aboriginum, are taller and extend through the woodland canopy, and only these two species occupy habitats where the woodland vegetation is taller, on N- and NE-facing aspects where incident radiation levels are lowest. Two species, Stenocereus standleyi and Cephalocereus purpusii, are shorter, subcanopy species, and are more restricted to low-angle slopes and slopes with S- to W-aspects, where the woodland vegetation is shorter and more open, with a greater penetration of radiation into the vegetation. Branching morphology is affected by the vegetation cover in all species, but in different ways between the two taller and the two shorter species. Ecological segregation in these four species is achieved apparently by differences among the light regimes of subhabitats correlated to the morphology of the cacti. This contrasts to segregation in Sonoran Desert columnar cactus species, which segregate by different strategies of water uptake and utilization, and in columnar cacti in woodlands in Oaxaca further south in Mexico, where adult individuals are very similar in branching morphology, but the younger individuals differ in this respect and presumably become established in different sorts of light gaps.

Morphology, Surface Temperatures, and Northern Limits of Columnar Cacti in the Sonoran Desert

Interspecific morphological differences and intraspecific morphological changes with latitude were evaluated to help examine the distributional ranges of Carnegiea gigantea, Lemaireocereus thurberi, Lophocereus schottii, Pachycereus pecten—aboriginum, and P. pringlei in the Sonoran Desert (USA and Mexico). A computer model, which predicted the average surface temperature of the stem within 1°C of that measured hourly throughout a 24—h period, was particularly useful in studying the thermal relations of the stem apex, where the lowest surface temperature occurred. Simulated increases in stem diameter raised the minimum apical temperature for C. gigantea and may help account for the extension of its range to higher latitudes than the other species studied. However, diameter increases led to a slight decrease in minimum apical temperatures for Lophocereus schottii. The immature stems of L. schottii are morphologically distinct from the mature stems which caused minimum apical temperatures to be 1.6°C lower for the immature stems under given environmental conditions; thus, freezing damage to the immature stems could limit the northward extension of the range of this species. As the apical pubescence in the simulations was increased up to the normal amount (10 mm), the minimum apical temperature for the stem of C. gigantea increased 2.4°C. Simulated increases in spine shading of the apex also raised the minimum apical temperatures, again indicating the influence of morphological features on the temperature of the meristematic region. Under the same environmental conditions the minimum apical temperatures were 7.7°C, 5.9°C, and 3.9°C for C. gigantea, Lemaireocereus thurberi, and immature stems of Lophocereus schottii, respectively, which is the same relative order as their northernmost limit (34°56'N, 32°38'N, and 31°55'N respectively). The northern limit for these three species, but not for Pachycereus pectenaboriginum and P. pringlei, may well be determined by the low temperatures occurring at the stem apex.