Browsing by Autor "Mario Coca Morante"

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Cercospora Leaf Spots of Wheat in the Lowland Tropics of Santa Cruz, Bolivia
(2024) Mario Coca Morante
The cultivation of wheat (Triticum aestivum L.) in the lowland tropics of Santa Cruz department in Bolivia is recent. Leaf spots diseases are an important yield-reducing factor. Since 1996, Pyricularia blast wheat is the most destructive disease in tropical regions producing wheat. In 2023, sampling was carried out in different locations in the East (Cuatro cañadas) and North (Okinawa1, Okinawa2) production wheat of Santa Cruz. Leaf, sheath and glumes simples were analyzed under microscopy and were estimated incidence. Two Cercospora species, C. oryzae and C. sorghi, were recorded associated with the leaf spots of 'Motacu' variety and these leaf spots seem to be prevalent and widely distributed in the production wheat áreas in the lowland tropics of Santa Cruz, Bolivia.
Cercospora Leaf Spots of Wheat in the Lowland Tropics of Santa Cruz, Bolivia
(2024) Mario Coca Morante
The cultivation of wheat (Triticum aestivum L.) in the lowland tropics of Santa Cruz department in Bolivia is recent. Leaf spots diseases are an important yield-reducing factor. Since 1996, Pyricularia blast wheat is the most destructive disease in tropical regions producing wheat. In 2023, sampling was carried out in different locations in the East (Cuatro cañadas) and North (Okinawa1, Okinawa2) production wheat of Santa Cruz. Leaf, sheath and glumes simples were analyzed under microscopy and were estimated incidence. Two Cercospora species, C. oryzae and C. sorghi, were recorded associated with the leaf spots of 'Motacu' variety and these leaf spots seem to be prevalent and widely distributed in the production wheat áreas in the lowland tropics of Santa Cruz, Bolivia.
Disease Note: First Records of Potato Late Blight Caused by Phytophthora infestans in Bolivia
(OMICS Publishing Group, 2016) Mario Coca Morante
Late blight, caused by the oomycete Phytophthora infestans, is one of the most destructive of all potato diseases. In the Bolivian Andes, it is common, but this does not seem to have always been the case. The aim of the present work was to review the historic literature to produce a record of the disease in Bolivia. No mention of late blight appears in any 19th century document. Indeed, the earliest mention of the disease is from 1943. Late blight would therefore seem to be a relatively new disease in Bolivia.
Distribution of wild potato species in the North of the Department of La Paz, Bolivia
(Spanish National Research Council, 2007) Mario Coca Morante; V.H. Ticona; W. Castillo Plata; I. Tolin Tordoya
From 2001 to 2003, field collections of wild potatoes (Solanum Section Petota Solanaceae) were made in the north of the Department of La Paz, Bolivia, with the aim of determining their current distribution in this region. The collection embraced sectors of five provinces: Omasuyos, Larecaja, Camacho, Muñecas and Bautista Saavedra. Five previously described wild species were collected: Solanum acaule Bitter, S. achacachense Cárdenas, S. brevicaule (Bitter) Juz and Buk, S. candolleanum Berthault and S. circaeifolium Bitter, as well as four unidentified species. Some wild potato species in Bolivia, such as S. achacachense, are rare and in danger of extinction because of the destruction of their habitat. In contrast, S. brevicaule, S. candolleanum and S. circaeifolium were recorded in new areas. Some species were affected by pests (Premnotrypes sp.) or the fungus Phytophthora infestans. This is the first time that "Lelekoyas" potatoes (S. tuberosum subsp. andigena) have been detected in the area of influence of Lake Titicaca. In summary, this work reports degrees of genetic erosion for some species, the finding of taxa in new geographical areas, some probable new species, and the presence of P. infestans in some of the species detected.
Emergent Viral Disease in Alfalfa (Medicago sativa L.) Plots in Cochabamba, Bolivia, a Preliminary Evaluation
(2022) Mario Coca Morante; Nilo Acha Molina; Arnold Calani Lucas; Ruddy Meneses Arce
Alfalfa (Medicago sativa L.) is one of the most important forage crops in the world. In Bolivia it is cultivated in different parts of the High Andes and in the Interandean Valleys. The species is affected by several fungal diseases which reduce production, but before 2016 hardly any mention had been made of virus disease in the region. The aims of the present work were: 1) to describe the symptomology of this apparent viral disease, and ii) determine its effects on the yield of different alfalfa cultivars available from the CIF-UMSS. In 2016, a plot was established at Tiquipaya (Dept. of Cochabamba) (altitude 2480 m) was planted with 12 alfalfa cultivars. Disease incidence values were estimated and the area under the disease progress curves (AUDPC) calculated. The disease progress curves themselves were analyzed using logit functions for polycyclic diseases, and yields were determined. Disease symptoms included deformation of the folioles, thickened veins, the presence of vein enations and papillae on the abaxial leaves, reduced plant size - all symptoms of infection apparently caused by Alfalfa Dwarf Virus. The different cultivars returned different incidence values. They also returned different apparent infection rates ranging from 0.072/day for C&oacute;ndor, to 0.113/day for Tamborada. The different cultivars returned different dry weight yields, with yields inversely related to the AUDPC. In conclusion, based on the foliar symptoms registered, the viral disease is associated with the Alfalfa Dwarf Virus. The twelve cultivars evaluated presented different incidence levels of the viral disease.
Estado actual de la producción de papa (Solanum tuberosum L.) en la región andina boliviana
(2016) Mario Coca Morante
El cultivo de la papa (Solanum tuberosum L.) es uno de los más importantes en la región Andina boliviana, tanto por su valor como cultivo de seguridad alimentaria y por su condición de centro de domesticación de una diversidad de papas nativas. Los diferentes procesos sociales, económicos y políticos de los últimos años vienen promoviendo un nuevo panorama de la tendencia de la producción de la papa en Bolivia. La imagen tradicional de país con agricultura eminentemente Andina e Interandina, con la ampliación de la frontera agrícola hacia zonas no tradicionales como los Valles Mesotérmicos, el oriente y chaco boliviano se encuentra configurando una nueva cultura del cultivo y consumo de la papa en Bolivia. El objetivo del presente trabajo fue describir el estado actual de la producción de papa en la región Andina boliviana a partir de la información existente. Se revisaron documentos, informes locales y publicaciones internacionales. Desde 1950, la introducción de tecnología para el mejoramiento de la producción de la papa en los Andes de Bolivia, comenzó apuntando a mejorar la calidad de la semilla de papa a partir de la evaluación y selección de variedades de papas nativas. Después de más de 60 años, en la actualidad, Bolivia, mantiene un sistema de producción y abastecimiento de semilla de papa de calidad certificada. Este sistema desde 1987 a la fecha ha promovido la producción de un número reducido de variedades de papas, entre ellas, la Desirée (Solanum tubersosum subsp. tuberosum) y Waych’a (Solanum tubersosum subsp. andigena). Este esquema junto a los patrones de consumo actual se encuentra modificando la realidad de la producción de la papa en Bolivia, cuyos efectos podrían causar impactos negativos en la conservación de la diversidad de las papas nativas y en la cultura de la papa en la región Andina.
Forest Andeans: Polylepis subtusalbida (Rosaceae) disease caused by Leptosphaeria sp in the National Park Tunari forest of Cochabamba, Bolivia.
(2022) Mario Coca Morante
Macromycete fungal diversity in the Andean Amazonian rainforest of the Sacta Valley, Cochabamba, Bolivia
(2023) Mario Coca Morante; Alejandro Coca‐Salazar; Olga Herrera Fernández; Casimiro Mendoza Bautista
Deforestation has affected the pre-Andean Amazonian tropical rainforests, as microregions are of relevant ecological and environmental importance for biodiversity conservation. Macromycetes are some of the organisms facing extinction owing to the alteration of which the natural tropical rainforests have been subjected. This work provides an inventory of the macromycetes inhabiting the last relicts of natural, unspoiled rainforest of the Department of Cochabamba, Bolivia, and reports the advancements made in their identification and classification. The inventory was taken in the permanently monitored plots established within the primary forest preserved by the San Simón University at the Valley of Sacta Fund. We found sixty-two different morphotypes, fifty-five of which are macromycetes and seven are not polypores. Fifty morphotypes were categorized as saprophytes living on dead trunks and branches and twelve morphotypes parasitizing living trunks of 17 tree species. Low macromycete species richness and the Shannon index (3.78) are indicative of low macrofungal diversity.
New Quinoa Disease (Chenopodium Quinoa Willd.) in Tropicalized and not Tropicalized Quinoa Crops in the Tropical Region of Cochabamba, Bolivia
(2024) Mario Coca Morante
Quinoa (Chenopodium quinoa Willd.) is traditionally cultivated in the Bolivia and Peru Andean region. In Bolivia, it is mainly cultivated in the southern, central and northern altiplano highlands (3800 masl). In recent years, research has been done on the tropicalization of this crop to introduce it to tropical regions of Bolivia for export purposes. In 2024, quinoa was planted in a location in the tropical Chapare (250 masl) Cochabamba region, a tropicalized variety (UAGRM-FINE) and another non-tropicalized variety from the Altiplano. In the fruiting and grain filling phenological phase, a disease occurred affecting both varieties, although with a higher incidence in the nontropicalized variety. After laboratory observation in a lactophenol solution, its morphological characteristics as conidiophore and conidia are coincident with the Periconia sp description. In conclusion, it is a new quinoa disease that affects tropicalized and non-tropicalized varieties in Bolivia.
Peligro de extinción de especies raras de papas silvestres de Bolivia
(2007) Mario Coca Morante
Short communication. Resistance to Phytophthora infestans in populations of wild potato species in the Sorata microcentre of genetic diversity, La Paz, Bolivia
(Spanish National Research Council, 2006) Mario Coca Morante; N. Montealegre Villanueva
Endemic wild potato species can be found in the Sorata microcentre of potato genetic diversity (Bolivia). This area, which lies at some 2640 m above sea level, is also a region of intensive phurejas potato cultivation. Pressure from the fungus Phytophthora infestans is high. In vitro experiments were performed to assess the resistance of the following potatoes to P. infestans: i) populations of the wild species Solanum acaule (S. acl), S. circaeifolium (S. crc-LA, S. crc-LB and S. crc-CO) and S. achacachense (S. ach), maintained at the Belén Research Station ex situ bank, ii) the reference species S. capsicibaccatum (S. cap), S. berthaultii (S. ber), S. toralapanum (S. tor) and S. sparsipilum (S. spl), and iii) susceptible cultivated varieties of S. phureja (S. phu) and S. tuberosum subsp. andigena (S. adg). The populations of S. acl, S. crc-LA, S. crc-LB and S. crc-CO showed high levels of resistance to P. infestans, while S. ach was very susceptible, in fact even more so than S. phu. S. tor was very resistant, while S. cap, S. ber and S. spl showed susceptibility similar to that of S. phu. The susceptible control S. adg showed the expected response to P. infestans, while that of S. phu was in agreement with its non-specific resistance to this pathogen.
Viral diseases associated to wild potatoes (Solanum L. section Petota Dumort) and its conservation in Bolivia
(University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, 2021) Mario Coca Morante; Nelson Tapia Ponce
Different species of wild potatoes are distributed in highlands and inter-Andean valleys of Bolivia. In recent years, potato virus’s incidence has been reported in native and modern varieties of Andean areas of Peru, Ecuador and Bolivia, which could also affect wild potatoes. The main of the present investigation was to identify potato viruses using DAS ELISA in wild potatoes species, from isolated collection places and intensive potato cultivation places in the Bolivian Andean region. Folioles samples from different wild potato species were collected considering isolated distribution areas and potato cultivation intensity areas. The samples were analysed using DAS ELISA for PRX, PVY, PLRV, APLV and APMoV viruses. The results show that in the high Andean zones and inter-Andean valleys some species are contaminated with PVX, PVY and PLRV viruses and not with APLV and APMoV. In the high Andean areas with intensive potato cultivation S. acaule is contaminated with PVX and S. megistacrolobum with PVY and PLRV; however, in the inter-Andean valley areas with intensive potato cultivation, S. brevicaule is contaminated with PVY and S. berthaultii with PVY and PLRV. In isolated or remote areas S. capsicibaccatum, S. microdontum and Solanum spp. they are not contaminated with any analysed viruses.
Virus Incidence Associated with Native Potato Yield in Microcenters of Potato Genetic Diversity of Bolivian
(Springer Science+Business Media, 2021) Mario Coca Morante; Evelyn Coca Salazar; Javier Burgos Villegas; Nelson Tapia Ponce
Abstract In the Bolivian Andean region, a diversity native potatoes species ( Solanum spp) are cultivated. Areas where many types of native potato are grown are known as microcentres of potato genetic diversity. However, yields are low in these places, apparently related to viral infections. The incidence of the potato-affecting viruses Potato Virus X (PVX), Potato Virus Y (PVY), Potato Leaf Roll Virus (PLRV), Andean Potato Latent Virus (APLV) and Andean Potato Mottle Virus (APMoV) was examined by DAS-ELISA in microcentres of two high Andean regions of Bolivia, i.e. an Aymara culture region in the north of La Paz, and a Quechua culture region in the Dept. of Cochabamba. The relationship between viral incidence and potato yield was explored as well. The presence of all five viruses was detected in both regions, except APMoV in the Aymara region. The mean overall incidence of viral infection was greater in the Aymara than in the Quechua region. The most commonly detected viruses were PVX, PVY and APLV. Mix-infections of PVY + PVX and PVY + PLRV were most common in the Aymara region, and PVX + APLV and PVX + APMoV in the Quechua region. Potato yield was less in Aymara than in Quechua region and it was correlated to higher incidence of PVY and PVX in Aymara region. Low yields and high incidence of viral infection seems to be related to the ancestral management by planting native seed potatoes of poor quality. In conclusion, four of the five viruses sought were detected in the Aymara region, and all five in the Quechua region, although the overall incidence of viral infection was greater in the Aymara region, where the yields recorded were also lower. Resumen. En la región andina boliviana se cultivan una diversidad de especies nativas de papa ( Solanum spp ). Las áreas donde se cultivan muchos tipos de papa nativa se conocen como microcentros de diversidad genética de la papa. Sin embargo, los rendimientos son bajos en estos lugares, aparentemente relacionados con infecciones virales. Se examinó la incidencia de los virus que afectan a la papa, el Virus X de la Papa (PVX), Virus Y de la Papa (PVY), Virus del Rollo de hoja de Papa (PLRV), Virus Latente de la Papa Andina (APLV) y Virus moteado de la Papa Andina(APMoV) por DAS-ELISA en microcentros de dos regiones altoandinas de Bolivia, por ejemplo, una región de cultivo Aymara en el norte de La Paz y una región de cultivo Quechua en el Departamento de Cochabamba. También se exploró la relación entre la incidencia viral y el rendimiento de la papa. Se detectó la presencia de los cinco virus en ambas regiones, excepto APMoV en la región Aymara. La incidencia global media de infección viral fue mayor en la región Aymara que en la región Quechua. Los virus más comúnmente detectados fueron PVX, PVY y APLV. Las infecciones por mezcla de PVY + PVX y PVY + PLRV fueron más comunes en la región Aymara, y PVX + APLV y PVX + APMoV en la región Quechua. El rendimiento de papa fue menor enAaymara que en la región Quechua y se correlacionó con una mayor incidencia de PVY y PVX en la región Aymara. Estamos evidenciando que los bajos rendimientos y la alta incidencia de infección viral parecen estar relacionados con el manejo ancestral mediante la siembra de papas de semilla nativa de mala calidad. En conclusión, cuatro de los cinco virus buscados se detectaron en la región Aymara, y los cinco en la región Quechua, aunque la incidencia general de infección viral fue mayor en la región Aymara, donde los rendimientos registrados también fueron menores.
Wild potato species (&lt;i&gt;Solanum&lt;/i&gt; section Petota &lt;i&gt;Solanaceae&lt;/i&gt;) in the Tunari National Park, Andean Region of Cochabamba, Bolivia
(Scientific Research Publishing, 2014) Mario Coca Morante; Alejandro Coca‐Salazar
The Tunari National Park is located in the Tunari Mountain Range, part of the Cochabamba Range in the Bolivian Andes. The Park is home to species of wild potato (Solanum section Petota Solanaceae), but these are now threatened by human activity. The aims of the present study were: 1) to determine the distribution of wild potato species in the Park, and, 2) to determine the size of their populations. Collection routes were established within the Park, and the species present along them recorded in 2006, 2007 and 2008. Their population sizes were determined in 2008. Four wild potato species were identified: S. capsicibaccatum, S. berthaultii, S. brevicaule and S. toralapanum. S. capsicibaccatum was the most abundant and had the most extensive distribution, followed by S. berthaultii; these last two species are likely endemic. The other species, although probably also endemic, were much less widely distributed; some limiting factor(s) would therefore appear to be acting upon them. S. berthaultii showed variations in corolla shape (rotate, pentagonal and semi-stellate) and flower colour (whitish-lilac to blue-lilac). The remaining species showed no apparent intraspecific variation in their morphological characteristics.
Wild potato species threatened by extinction in the Department of La Paz, Bolivia
(Spanish National Research Council, 2007) Mario Coca Morante; W. Castillo Plata
The Department of La Paz has the largest number of wild potato species (Solanum Section Petota Solanaceae) in Bolivia, some of which are rare and threatened by extinction. Solanum achacachense, S. candolleanum, S. circaeifolium, S. okadae, S. soestii and S. virgultorum were all searched for in their type localities and new areas. Isolated specimens of S. achacachense were found in its type localities, while S. candolleanum was found in low density populations. Solanum circaeifolium was also found as isolated specimens or in low density populations in its type localities, but also in new areas. Solanum soestii and S. okadae were found in small, isolated populations. No specimen of S. virgultorum was found at all. The majority of the wild species searched for suffered the attack of pathogenic fungi. Interviews with local farmers revealed the main factors negatively affecting these species to be loss of habitat through urbanization and the use of the land for agriculture and forestry. Some 37.8% of those interviewed knew the local uses of the wild potatoes studied.
Wild potatoes of series Circaeifolia (Solanun section Petota) in the Bolivian Andean region, a new evaluation of its distribution
(Academic Journals, 2020) Mario Coca Morante
The Circaeifolia series species are only from Bolivia. They are species that have particular morphological characteristics different from any other within the Petota section. The taxa of the series Circaeifolia, Solanum circaeifolim, Solanum capsicibaccatum and Solanum soestii (recently grouped as Solanum stipuloideum Rusby) have been distinguished by morphological characteristics and molecular analysis, however, they are not completely elucidated. Until 1994, some taxa, S. circaeifolium and S. soestii, had been considered "rare" because of their restricted geographic distribution. However, with recent data a new situation can be inferred for these Circaeifolia species. S. soestii, may be considered "rare" because it is confined to its type of locality or have restricted geographic distribution; conversely, S. circaeifolium and S. capsicibaccatum have a greater known distribution until 1994. Besides, several factors, such as anthropogenic activities (forest plantation, urbanization and agriculture expansion) and others related to climate change, like drought and forest fires, are threatening their extinction.   Key words: Section petota, rare species, climate change.
Wilt Disease of Tara (&lt;i&gt;Caesalpinia spinose&lt;/i&gt; Molina Kuntz) in Nursery in the Inter Andean Valley of Cochabamba, Bolivia
(Scientific Research Publishing, 2018) Mario Coca Morante
Tara (Caesalpinia spinose Molina Kuntz) is a native plant of the Bolivian Andes. A number of projects have promoted the cultivation of this species over the last 20 years, in efforts to make use of its medicinal, food and industrial properties. However, as tara plantations have grown, so too has the incidence of disease affecting the species, leading to economic losses. The aim of the present work was to identify the causal agent of wilting in tara, and to determine the incidence of the disease in nursery-grown plants. Three experimental plots (R1-R3) were established in plantlet production bedsat the ESFOR nursery in order to assess the incidence of wilting. Plant spacing was 1 × 1 m. At the two leaf stage, samples of diseased and apparently healthy plants were taken to the laboratory for the isolation of pathogens. Both the apparently healthy and diseased plants gave rise to the same kinds of fungal colony on PDA. Microscopic examination revealed microconidia, macroconidia, phialides and chlamydospores suggesting the causal agent to be Fusarium oxysporum. Over the (up to) 84-day period following thinning, the incidence of wilting for 2010 was R1 = 2.56%, R2 = 3.15% and R3 = 2.22% per 14 days, and for 2013 it was R1 = 1.24%, R2 = 2.45% and R3 = 2.13% per 14 days; the apparent infection rates for 2010 were rR1 = 0.0003/day, rR2 = 0.0003/day and rR3 = 0.0003/day, and for 2013 they were rR1 = 0.0003/day, rR2 = 0.0004/day and rR3 = 0.0003/day. These values are characteristic of monocyclic epiphytic fungi such as F. oxysporum.