Phytophthora ipomoeae sp. nov., a new homothallic species causing leaf blight on Ipomoea longipedunculata in the Toluca Valley of central Mexico

2002 ◽  
Vol 106 (7) ◽  
pp. 848-856 ◽  
Author(s):  
Wilbert G. Flier ◽  
Niklaus J. Grünwald ◽  
Laurens P.N.M. Kroon ◽  
Trudy B.M. Van Den Bosch ◽  
Edith Garay-Serrano ◽  
...  
Keyword(s):  
Leaf Blight ◽  
Central Mexico ◽  
Toluca Valley

The Sixteenth-Century Zinacantepec Census: Between Ethnohistory and Historical Demography

Ethnohistory ◽  
2020 ◽  
Vol 67 (2) ◽  
pp. 289-315
Author(s):  
Amos Megged
Keyword(s):  
Sixteenth Century ◽  
Population Data ◽  
Central Mexico ◽  
Population Movements ◽  
Migration Patterns ◽  
Spanish Conquest ◽  
Before And After ◽  
Toluca Valley ◽  
And Migration ◽  
The Town

Abstract While earlier census studies yielded population data mainly for the Tepetlaoztoc and Morelos regions of central Mexico during the 1530s and 1540s, this ethnohistoric study, based on a newly discovered manuscript, sheds light on household types and population density in the town of Zinacantepec by 1574. By comparing population figures, household types, and migration patterns, this article reconsiders how Aztec invasion, and thereafter the Spanish conquest, affected population movements and stability in the Valley of Toluca, a former Aztec stronghold in central Mexico. Furthermore, the nature of Toluca Valley habitats may prompt us to rethink about how we interpret the nature of indigenous demographic layouts before and after the Spanish conquest, whether its features be urban or rural.

scholarly journals Parasites in feces of the endemic rattlesnake, Crotalus triseriatus (Serpentes: Viperidae), from Mexican highlands

2019 ◽  
Vol 36 ◽  
pp. 1-6
Author(s):  
Leroy Soria-Díaz ◽  
Jaime Luis Rábago-Castro ◽  
Hublester Domínguez-Vega ◽  
Yuriana Gómez-Ortíz ◽  
Javier Manjarrez ◽  
...  
Keyword(s):  
Population Health ◽  
Wildlife Conservation ◽  
Parasitic Infections ◽  
Central Mexico ◽  
Fecal Samples ◽  
Reptile Species ◽  
Flotation Technique ◽  
Toluca Valley

There are few studies about parasitic infections in Crotalus triseriatus (Wagler, 1830), an endemic rattlesnake from the highlands of central Mexico. This species occupies several habitats, from conserved forested regions to heavily impacted landscapes. To increase the parasitological knowledge of this reptile species without impacting populations, we obtained fecal samples of 16 rattlesnakes between 2012 and 2014 from Toluca Valley, Mexico. By using flotation technique, we found oocysts of Eimeria sp. and eggs of Capillariidae sp. The most frequent parasite was Eimeria sp. (62.5%). This study provides the first records of occurrence of parasites in reptilian feces from Mexico. Our results may be important for wildlife conservation purposes, for example, they could indicate of the population health of this species during processes of translocation.

Formation, production and viability of oospores of Phytophthora infestans from potato and Solanum demissum in the Toluca Valley, central Mexico

2001 ◽  
Vol 105 (8) ◽  
pp. 998-1006 ◽  
Author(s):  
Wilbert G. Flier ◽  
Niklaus J. Grünwald ◽  
William E. Fry ◽  
Lodewijk J. Turkensteen
Keyword(s):  
Phytophthora Infestans ◽  
Central Mexico ◽  
Solanum Demissum ◽  
Toluca Valley

scholarly journals Radiocarbon Dating of Underwater Archaeological Objects from the Nevado de Toluca, Mexico

Radiocarbon ◽  
2017 ◽  
Vol 59 (6) ◽  
pp. 1705-1712 ◽  
Author(s):  
M A Martínez-Carrillo ◽  
C Solís ◽  
I Hernández Bautista ◽  
R Junco Sánchez ◽  
M Rodríguez-Ceja ◽  
...  
Keyword(s):  
Radiocarbon Dating ◽  
Central Mexico ◽  
Crater Lakes ◽  
Spanish Conquest ◽  
Long Duration ◽  
Toluca Valley ◽  
Nevado De Toluca ◽  
Archaeological Objects ◽  
La Luna

ABSTRACTThe Nevado de Toluca is a stratovolcano located in the southwest of the Toluca Valley in central Mexico. At a height of around 4200 m there are two crater lakes: El Sol and La Luna. Since Precolumbian times, people in the surrounding valleys carried out rituals and deposited offerings into the lakes. After the Spanish conquest, these rituals were kept alive clandestinely. Currently, reminiscent of Mesoamerican rituals subsist. Due to the long duration of the ritual at the Nevado de Toluca, it is important to date the materials recovered in the underwater and terrestrial archaeological explorations. This article proposes a chronology of Prehispanic ritual activities performed in the Nevado de Toluca based on the characterization and radiocarbon (14C) dating performed to materials from the volcano’s lakes.

scholarly journals Potato Late-Blight Management in the Toluca Valley: Forecasts and Resistant Cultivars

Plant Disease ◽  
2000 ◽  
Vol 84 (4) ◽  
pp. 410-416 ◽  
Author(s):  
Niklaus J. Grünwald ◽  
Oswaldo A. Rubio-Covarrubias ◽  
William E. Fry
Keyword(s):  
Low Temperature ◽  
Late Blight ◽  
Host Resistance ◽  
Integrated Management ◽  
Temperature Response ◽  
Central Mexico ◽  
Susceptible Cultivar ◽  
Toluca Valley ◽  
High Level ◽  
Late Blight Management

We evaluated host resistance and fungicide forecasting as components of integrated management in the Toluca Valley of central Mexico. Potato cvs. Rosita and Norteña showed high levels of resistance (20 and 4% final disease severity, respectively) in the no-spray controls, whereas susceptible cv. Alpha was at 90% defoliation well before the end of the season. Disease on Alpha was well managed with a weekly spray of chlorothalonil. None of three published forecast systems was entirely appropriate for this pathosystem. SIM-CAST accurately allocated fungicide for a susceptible cultivar but needs to be adapted for the high level of resistance of Rosita and Norteña. TOM-CAST and BLITECAST did not recommend the initial fungicide application until after disease was well established in the plots. We believe that the low-temperature response of Phytophthora infestans needs to be reevaluated for the highland tropics.

scholarly journals Formation of Phytophthora infestans Oospores in Nature on Tubers in Central Mexico

Plant Disease ◽  
2002 ◽  
Vol 86 (1) ◽  
pp. 73-73 ◽  
Author(s):  
S. P. Fernández-Pavía ◽  
N. J. Grünwald ◽  
W. E. Fry
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Field Conditions ◽  
Central Mexico ◽  
Potato Tubers ◽  
Dry Rot ◽  
Pink Rot ◽  
Phytophthora Erythroseptica ◽  
Oospore Formation ◽  
Toluca Valley

Oospore formation by Phytophthora infestans in nature has been detected on potato leaflets in central Mexico (1), but there are no reports of oospore formation on tubers. A severe late blight epidemic occurred in Calimaya, Mexico, in fields where potato cv. Alpha was planted during the summer of 2000. Yield was reduced despite numerous applications of fungicide. Four hundred potato tubers left in the field were collected from the upper 10 cm of soil and examined for late blight symptoms. Tubers with soft and dry rot symptoms were observed, but symptoms of pink rot (Phytophthora erythroseptica) were not found. Four percent of the tubers showed late blight symptoms. Sections of 10 tubers with late blight symptoms were air-dried for 2 weeks in the laboratory and homogenized with a mortar and pestle. Glycerol was added to the homogenized tissue and observed microscopically. Aplerotic oospores (10 to 15 oospores per tuber) with amphyginous antheridia typical of P. infestans were observed. P. mirabilis morphologically similar to P. infestans is present in the area but it does not infect potato tubers. The number of oospores observed in our tuber sample was much lower than the number reported on leaflets (>1,000 oospores per leaflet) in the Toluca Valley. Low numbers of oospores have been reported on tubers artificially inoculated with P. infestans under field conditions (2). Infected tubers left in the field may act as a source of primary inoculum. To our knowledge, this is the first report of oospores of P. infestans found on tubers in Mexico under natural field conditions. References: (1) M. E. Gallegly and J. Galindo. Phytopathology 48:274, 1958. (2) A. Levin et al. Phytopathology 91:579, 2001.

scholarly journals The Population Structure of Phytophthora infestans from the Toluca Valley of Central Mexico Suggests Genetic Differentiation Between Populations from Cultivated Potato and Wild Solanum spp.

2003 ◽  
Vol 93 (4) ◽  
pp. 382-390 ◽  
Author(s):  
Wilbert G. Flier ◽  
Niklaus J. Grünwald ◽  
Laurens P. N. M. Kroon ◽  
Anne K. Sturbaum ◽  
Trudy B. M. van den Bosch ◽  
...  
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Phytophthora Infestans ◽  
Central Mexico ◽  
Commercial Potato ◽  
Cultivated Potatoes ◽  
Toluca Valley ◽  
Solanum Spp ◽  
Mtdna Haplotype ◽  
Wild Solanum

The population structure of Phytophthora infestans in the Toluca Valley of central Mexico was assessed using 170 isolates collected from cultivated potatoes and the native wild Solanum spp., S. demissum and S. xendinense. All isolates were analyzed for mitochondrial DNA (mtDNA) haplotype and amplified fragment length polymorphism (AFLP) multi-locus fingerprint genotype. Isolate samples were monomorphic for mtDNA haplotype because all isolates tested were of the Ia haplotype. A total of 158 multilocus AFLP genotypes were identified among the 170 P. infestans isolates included in this study. P. infestans populations sampled in the Toluca Valley in 1997 were highly variable and almost every single isolate represented a unique genotype based on the analysis of 165 AFLP marker loci. Populations of P. infestans collected from the commercial potato-growing region in the valley, the subsistence potato production area along the slopes of the Nevado de Toluca, and the native Solanum spp. on the forested slopes of the volcano showed a high degree of genetic diversity. The number of polymorphic loci varied from 20.0 to 62.4% for isolates collected from the field station and wild Solanum spp. On average, 81.8% (135) of the AFLP loci were polymorphic. Hetero-zygosity varied between 7.7 and 19.4%. Significant differentiation was found at the population level between strains originating from cultivated potatoes and wild Solanum spp. (P = 0.001 to 0.022). Private alleles were observed in individual isolates collected from all three populations, with numbers of unique dominant alleles varying from 9 to 16 for isolates collected from commercial potato crops and native Solanum spp., respectively. Four AFLP markers were exclusively found present in isolates collected from S. demissum. Indirect estimation of gene flow between populations indicated restricted gene flow between both P. infestans populations from cultivated potatoes and wild Solanum hosts. There was no evidence found for the presence of substructuring at the subpopulation (field) level. We hypothesize that population differentiation and genetic isolation of P. infestans in the Toluca Valley is driven by host-specific factors (i.e., R-genes) widely distributed in wild Solanum spp. and random genetic drift.

Sign in / Sign up

Export Citation Format

Share Document