RESUMO
Pinus eldarica, P. halepensis and P. radiata are important conifer species native to Mediterranean regions that are cultivated in the southwestern United States for landscaping (Phillips and Gladfelter, 1991; Chambel et al., 2013). Among them, Monterey pine (P. radiata) is native to restricted areas of California and Mexico, but it is extensively grown for timber production in other countries, especially in the Southern Hemisphere (Rogers, 2004). From 2018 to 2022, severe dieback and cankers have been detected on more than 30 mature pines of the three species within a 40-ha urban forest in Orange County, Southern California. Symptoms initiate on the lower portion of the canopy and advance into the crown, leading to quick dieback and, in some cases, to tree death. Cross sections of affected branches revealed wedged cankers with irregular, indistinct margins, and cryptic discoloration (i.e., "ghost cankers"). Pycnidia were observed on the surface of each bark scale of branches with advanced infections. Two morphotypes of Botryosphaeriaceae colonies (n = 34 isolates) were recovered consistently from more than 90% of the symptomatic pines. Two isolates per morphotype were grown on pistachio leaf agar (Chen et al., 2014) for 14 days to induce pycnidia formation. Conidia (n = 50) were hyaline, thin-walled and fusoid to ellipsoidal in shape, ranging from 16.1 to 27.9 (22.6) × 5.4 to 8.2 (6.8) µm for the first morphotype and 11.5 to 20.4 (16.3) × 4.8 to 8.6 (6.3) µm for the second morphotype. The rDNA internal transcribed spacer (ITS), beta-tubulin (tub2), and translation elongation factor 1-alpha (tef1-α) partial gene regions were amplified and sequenced using the primers ITS5/ITS4 (White et al., 1990), Bt2a/Bt2b (Glass and Donaldson, 1995), and EF1-728F/EF1-986R (Carbone and Kohn, 1999), respectively. A multi-locus phylogenetic analysis revealed that isolates UCD9433 and UCD10439 clustered with the ex-type strain of Neofusicoccum mediterraneum (CBS:113083), and isolates UCD9161 and UCD9434 grouped with N. parvum (CMW:9081). Sequences were submitted to GenBank (nos. OP535391 to OP535394 for ITS, OP561946 to OP561949 for tef1-α, and OP561950 to OP561953 for tub2). Pathogenicity tests were performed with above-mentioned isolates on 20-mm-diameter healthy branches of mature Monterey pines (n = 10, 14 years old) located in a research field at UC Davis. Isolates were grown for 7 days on potato dextrose agar and inoculated in the internode area by removing a 5-mm-diameter disk of the bark with a sterile cork borer and placing a 5-mm-diameter mycelial plug. Controls were mock-inoculated with sterile agar plugs, and the experiment was performed twice. After three months, inoculations resulted in vascular lesions that ranged from 20.6 to 49.7 (32.7) mm with N. mediterraneum and from 13.5 to 71.0 (33.6) mm with N. parvum, and the same pathogens were reisolated (70 to 100% recovery). Controls remained symptomless and no botryosphaeriaceous colonies were recovered. Both N. mediterraneum and N. parvum are polyphagous pathogens associated with multiple woody plant hosts (Phillips et al., 2013). Previously, only N. parvum has been associated with pine cankers in Iran, however, the pine species was not indicated (Abdollahzadeh et al., 2013). The detection of these pathogens in urban forests raises concerns of potential spillover events to other forest and agricultural hosts in Southern California. To our knowledge, this is the first report of N. mediterraneum and N. parvum causing Pine Ghost Canker on P. eldarica, P. halepensis and P. radiata.
RESUMO
Central Mexico is characterized by a complex topography that is the result of historic and contemporary tectonic and climatic factors. These events have influenced the evolutionary history of numerous freshwater fishes in the region. Nonetheless, recent studies have shown that life-history traits and ecological characteristics of species may influence dispersal capabilities and the degree of genetic connectivity. Goodea (Cyprinodontiformes: Goodeidae) is one of the most widely distributed and environmentally tolerant genera of goodeids. In this study, the authors analysed variation in the mitochondrial cytochrome b gene to evaluate the phylogeographic relationships, genetic structure, genetic diversity and demographic history of Goodea from across its distribution range. They found low genetic differentiation and identified shared haplotypes among several regions. Geographic segregation was found in samples southwest and northeast of the Lower Lerma region, with some internal isolated groups showing phylogeographic differentiation and unique haplotypes. The AMOVA best explained genetic structure when grouped by haplogroups rather than when grouped by recognized biogeographic regions. Several regions showed null genetic diversity, raising the possibility of dispersal mediated by humans. Finally, Bayesian Skyline Plot analysis showed a population expansion for the Southwest haplogroup, except for the Armería population and sub-group II of the Northeast haplogroup. All this suggests a recent colonization of Goodea atripinnis throughout some of the biogeographic regions currently inhabited by this species.
Assuntos
Evolução Biológica , Ciprinodontiformes/classificação , Ciprinodontiformes/genética , Variação Genética , Distribuição Animal , Animais , Teorema de Bayes , Citocromos b/genética , Água Doce , Genes Mitocondriais/genética , Deriva Genética , Genética Populacional , Haplótipos , México , FilogeografiaRESUMO
The effects of invasive species on native ecosystems are varied, and these have been linked to the disappearance or decline of native fauna, changes in community structure, modification of ecosystems and as vectors of new diseases and parasites. Besides, the development of trade in species for ornamental use has contributed significantly to the import and introduction of invasive fish in some important areas for biodiversity conservation in Mexico, but the presence of these species is poorly documented. In this study we analyzed the fish community in the Biosphere Reserve Sierra de Huautla by looking at diversity changes in the last 100 years. For this, we used databases of historical records and recent collections for five sites in the Amacuzac river, along the Biosphere Reserve area. We compared the values of similarity (Jaccard index) between five times series (1898-1901, 1945-1953, 1971-1980, 1994-1995 and 2008-2009), and we obtained values of similarity (Bray-Curtis) between the five sites analyzed. In our results we recognized a total of 19 species for the area, nine non-native and ten native, three of which were eliminated for the area. Similarity values between the early days and current records were very low (.27); the major changes in the composition of the fauna occurred in the past 20 years. The values of abundance, diversity and similarity among the sampling sites, indicate the dominance of non-native species. We discuss the role of the ornamental fish trade in the region as the leading cause of invasive introduction in the ecosystem and the possible negative effects that at least four non-native species have had on native fauna and the ecosystem (Oreochromis mossambicus, Amatitlania nigrofasciata, Pterygoplichthys disjunctivus and P pardalis). There is an urgent need of programs for registration, control and eradication of invasive species in the Sierra de Huautla Biosphere Reserve and biodiversity protection areas in Mexico.
Assuntos
Peixes/classificação , Espécies Introduzidas/estatística & dados numéricos , Animais , Biodiversidade , Ecossistema , México , Densidade Demográfica , Dinâmica Populacional , Análise de Componente Principal , Estações do AnoRESUMO
Resumen Introducción: La diversidad de una comunidad biológica es el resultado de procesos ecológicos e históricos, los cuales, analizados en conjunto, producen una mejor comprensión de las causas que la generan. Objetivo: Actualizamos y analizamos la diversidad específica y taxonómica de la ictiofauna del río Amacuzac, México. Métodos: Durante cinco temporadas de muestreo (2019-2020), recolectamos peces de diez sitios en el río y aplicamos un análisis de conglomerados a las variables del hábitat. Resultados: Recolectamos 7 638 individuos, siete de especies nativas y nueve no nativas, incluyendo Copadichromis borleyi, un nuevo registro para el Amacuzac. La riqueza por sitio osciló entre ocho y 13 especies. Las variables del hábitat definieron cuatro grupos. Las especies más abundantes fueron: Poeciliopsis gracilis, Poecilia maylandi y Amatitlania nigrofasciata. Las especies menos abundantes fueron: Pterygoplichtys pardalis, Ilyodon whitei, Copadichromis borleyi e Ictalurus punctatus. Las especies más relevantes fueron: A. nigrofasciata, Amphilophus istlanus, Andinoacara rivulatus, Notropis boucardi, Oreochormis sp., P. maylandi, P. gracilis y Thorichthys maculipinis. Las especies más restringidas fueron: Atherinella balsana, C. borleyi e I. punctatus. Conclusiones: Las especies en peligro de extinción, A. istlanus y N. boucardi, aun prevalecen en el río. Además, se muestra un aumento en el número de especies no nativas. Analizar la diversidad desde dos perspectivas, aporta una visión más completa de los cambios que se dan en el Río Amacuzac como consecuencia del establecimiento de especies, información que es importante para futuras estrategias de conservación.
Abstract Introduction: The diversity of a biological community is the result of ecological and historical processes, which, when analyzed jointly, produce a better understanding of the causes that generate it. Objective: We update and analyze the specific and taxonomic diversity of the ichthyofauna of the Amacuzac River, Mexico. Methods: During five sampling seasons (2019-2020) we collected fishes from ten sites in the river and applied a cluster analysis to habitat variables. Results: We collected 7 638 individuals; seven were native species and nine were non-native, including Copadichromis borleyi, a new record for the Amacuzac. Richness per site ranged from eight to 13 species. Habitat variables defined four groups. The most abundant species were Poeciliopsis gracilis, Poecilia maylandi and Amatitlania nigrofasciata. The least abundant species were: Pterygoplichtys pardalis, Ilyodon whitei, Copadichromis borleyi and Ictalurus punctatus. The most prevalent species were: A. nigrofasciata, Amphilophus istlanus, Andinoacara rivulatus, Notropis boucardi, Oreochormis sp., P. maylandi, P., gracilis and Thorichthys maculipinis. The most restricted species were: Atherinella balsana, C. borleyi and I. punctatus. Conclusions: Endangered species such as A. istlanus and N. boucardi are still prevalent in the river, but non-native species continue to increase. Analyzing the diversity from two perspectives provides a more complete view of the changes taking place in the Amacuzac River as a consequence of species establishment, information that is important for future conservation strategies.
Assuntos
Animais , Fauna Aquática , Rios , Biodiversidade , MéxicoRESUMO
Historical presence of invasive fish in the Biosphere Reserve Sierra de Huautla, Mexico. The effects of invasive species on native ecosystems are varied, and these have been linked to the disappearance or decline of native fauna, changes in community structure, modification of ecosystems and as vectors of new diseases and parasites. Besides, the development of trade in species for ornamental use has contributed significantly to the import and introduction of invasive fish in some important areas for biodiversity conservation in Mexico, but the presence of these species is poorly documented. In this study we analyzed the fish community in the Biosphere Reserve Sierra de Huautla by looking at diversity changes in the last 100 years. For this, we used databases of historical records and recent collections for five sites in the Amacuzac river, along the Biosphere Reserve area. We compared the values of similarity (Jaccard index) between five times series (1898-1901, 1945-1953, 1971-1980, 1994-1995 and 2008-2009), and we obtained values of similarity (Bray-Curtis) between the five sites analyzed. In our results we recognized a total of 19 species for the area, nine non-native and ten native, three of which were eliminated for the area. Similarity values between the early days and current records were very low (.27); the major changes in the composition of the fauna occurred in the past 20 years. The values of abundance, diversity and similarity among the sampling sites, indicate the dominance of non-native species. We discuss the role of the ornamental fish trade in the region as the leading cause of invasive introduction in the ecosystem and the possible negative effects that at least four non-native species have had on native fauna and the ecosystem (Oreochromis mossambicus, Amatitlania nigrofasciata, Pterygoplichthys disjunctivus and P. pardalis). There is an urgent need of programs for registration, control and eradication of invasive species in the Sierra de Huautla Biosphere Reserve and biodiversity protection areas in Mexico. Rev. Biol. Trop. 60 (2): 669-681. Epub 2012 June 01.
Los efectos de las especies invasoras en los ecosistemas nativos son variados, y estos se han vinculado con la desaparición o disminución de la fauna nativa, cambios en la estructura de la comunidad, modificación de los ecosistemas y como vectores de nuevas enfermedades y parásitos. El desarrollo del comercio de especies para uso ornamental ha contribuido significativamente a la importación e introducción de peces invasores en algunas áreas importantes para la conservación de la biodiversidad en México, pero la presencia de estas especies está escasamente documentada. En este estudio se analiza la comunidad de peces en la reserva de Biosfera Sierra de Huautla, registrando los cambios en la diversidad en los últimos 100 años. Con bases de datos de registros históricos y recientes colecciones para cinco sitios en el río Amacuzac, que cruza la zona de reserva de la Biosfera, se comparan los valores de similitud (índice de Jaccard) entre cinco series de tiempo (1898-1901, 1945-1953, 1971-1980, 1994-1995 y 2008-2009), así mismo, obtuvimos los valores de similitud (Bray-Curtis) entre los cinco sitios analizados. En total hemos reconocido 19 especies para el área, diez nativas y nueve no nativas, de las cuales tres están extirpadas para el área, los valores de similitud entre los primeros registros y los actuales son muy bajos (0.27), los principales cambios en la composición de la fauna se han producido en los últimos 20 años. Los valores de abundancia, diversidad y similitud entre los sitios de muestreo, indican el predominio de especies no nativas. Discutimos el papel del comercio de peces ornamentales de la región como la principal causa de introducción de invasoras en el ecosistema, y los posibles efectos negativos que han tenido al menos cuatro especies en la fauna nativa y el ecosistema (Oreochromis mossambicus, Amatitlania nigrofasciata, Pterygoplichthys disjunctivus y P. pardalis), se hace notar la ausencia de programas de registro, ...