Estudio de la Variabilidad Genética en poblaciones naturales de Sacha Inchi Plukenetia Volubilis L. (Euphorbiaceae) de la región San Martín

In the Amazon area, the Euphorbiacea family is constituted by species of great economic importance such as sacha inchi Plukenetia volubilis L. (Linnaeus, 1753) Currently this species has been investigated concerning culture, but there is little about its genetic information, especially in natural populations. In this regard the present investigation tries to contribute to the knowledge of the genetic variability of sacha inchi in natural populations of the San Martín region. These populations were evaluated by means of the molecular technique DALP. A total of 83 samples collected in the localities of Havana (21), Shica (20), Cerro Alto (21) and Tununtunumba (21) was analyzed with the technique DALP “Direct Amplification of Length of Polymorphism”. From eight DALP markers used, three turned out to be informative (DALP221, DALP233 y DALP242), showing differences at an intra and inter-population level. The results of the AFC, index of fixation (average of Fst = 0.82) and genetic distance (average of D = 2.56) show that the four populations form independent genetic organizations. This could be attributed to the mixed pollinization system (autogamy and allogamy) present in this species. That would be acting preferably only between the individuals of each population, but not between different populations. At an intrapopulation level the population of Shica has the greatest genetic diversity (15 genotypes) of the four studied populations, which would be related to the great size and population density. This would favor the cross- fertilization, having as a consequence a greater genetic diversity. The high genetic diversity between the four populations of this species could be due to the absence of direct pollinizer insects as well as the presence of natural barriers and the geographic distance between them, which would be restricting the gene flow between the populations.En la Amazonía, la familia Euphorbiacea está constituida por especies de gran importancia económica como lo es el sacha inchi Plukenetia volubilis L. Actualmente esta especie viene siendo ampliamente investigada a nivel de cultivo, pero existe una reducida información a nivel genético, especialmente en poblaciones naturales. En este sentido, el presente estudio pretende contribuir al conocimiento de la variabilidad genética del sacha inchi en poblaciones naturales de la región San Martín, evaluadas mediante la técnica molecular DALP. Para lo cual, un total de 83 muestras fueron colectadas en las localidades de Habana (21), Shica (20), Cerro Alto (21) y Tununtunumba (21). El estudio fue basado en el análisis de ocho marcadores DALP; de los cuales, tres (DALP221, DALP233 y DALP242) resultaron ser informativos para esta especie, mostrando diferencias a nivel intra e interpoblacional. Los resultados del Análisis Factorial de Correspondencia (AFC), Índice de fijación (promedio de Fst = 0.83) y distancia genética (promedio de D = 2.56) muestran que las cuatro poblaciones estudiadas forman entidades genéticas independientes. Esto, podría ser atribuido al sistema mixto de polinización (autógamo y alógamo) presente en esta especie, que estaría actuando preferentemente dentro de cada población y no entre las poblaciones. A nivel intrapoblaciona, la población Shica presento la mayor diversidad genética (15 genotipos) entre las cuatro poblaciones estudiadas, lo cual estaría relacionado con el mayor tamaño y densidad poblacional, que favorecería la polinización cruzada, trayendo como consecuencia una mayor diversidad genética. La alta divergencia (diferenciación) genética encontrada entre las cuatro poblaciones evaluadas, podría ser causada por la ausencia de insectos polinizadores directos, así como por la presencia de barreras naturales y por la distancia geográfica entre ellas, que estaría restringiendo el flujo de genes entre las poblaciones.Tesi

Funneliglomus, gen. nov., and Funneliglomus sanmartinensis, a new arbuscular mycorrhizal fungus from the Amazonia region in Peru

A new arbuscular mycorrhizal fungus was found in agricultural field sites in the Amazonia lowlands of the Department San Martin, Perú. It was found up to 858 m above sea level in two plantations of the inka nut (also called ‚sacha inchi', Plukenetia volubilis), which was grown in mixed cultures together with Musa sp., Zea mays, Phaseolus vulgaris and Carica papaya. The fungus was propagated in bait cultures in a greenhouse on Sorghum sp., Brachiaria sp., Medicago sativa and Plukenetia volubilis as host plants. The fungus differentiates orange brown to dark orange brown, triple-layered spores, 93-151× 90-148 µm in diameter, terminally on funnel-shaped to rarely cylindrical or slightly inflating hyphae, and a strong, straight to slightly recurved septum that closes the spore pore at the spore base. Phylogenetically, the new fungus represents clearly a new genus in a separated clade, near to Funneliformis and Septoglomus. It can easily be distinguished from all other species of these genera by the characteristic ornamentation of the spore surface, which consists of multiple large, irregular pits. The fungus is here described under the epithet Funneliglomus sanmartinensis, serving as type species of the new genus Funneliglomus

A pathogen complex between the root knot nematode Meloidogyne incognita and Fusarium verticillioides results in extreme mortality of the inka nut (Plukenetia volubilis)

The combined infection of the root knot nematode Meloidogyne incognita and two Fusarium species led to high plant mortality of inka nut (Plukenetia volubilis) seedlings in pots after 80 days growth in two independent inoculation experiments. Inoculation of M. incognita juveniles and conidia of F. solani or F. verticillioides, simultaneously, increased plant mortality by 25-30%, compared with M. incognita alone (5-10% mortality). When inoculated with F. verticillioides at 20 days post nematode inoculation, plant mortality increased to 55%. Either of the Fusarium spp. alone caused some plant mortality, but less than when combined with M. incognita. The synergistic interaction of M. incognita and especially F. verticillioides demonstrates a lethal outcome for inka nuts. It appears that M. incognita creates favorable conditions that lead to enhanced effect and damage by the Fusarium species, especially F. verticillioides, leading to devastating levels of plant death

Acaulospora flava, a new arbuscular mycorrhizal fungus from Coffea arabica and Plukenetia volubilis plantations at the sources of the Amazon river in Peru

A new arbuscular mycorrhizal fungus, Acaulospora flava, was found in coffee (Coffea arabica) and inka nut (Plukenetia volubilis) plantations in the Amazonia region of San Martín State in Peru. The fungus was propagated in bait cultures on Sorghum vulgare, Brachiaria brizantha and Medicago sativa as host plants. It differentiates typical acaulosporoid spores laterally on sporiferous saccule necks. The spores are light yellow, bright yellow to yellow brown, (95-)105-160 × (95-)100-150 μm in diameter and have smooth spore surfaces. Phylogenetically, A. flava clusters in a well-separated clade, nearest to A. kentinensis, followed by A. herrerae, A. spinosissima, A. excavata and A. aspera, of which remarkably A. spinosissima, A. excavata and A. aspera had also been found in inka nut plantations of San Martín State during the last years. Here, we report also A. herrerae and A. fragilissima as fungal symbionts within the rhizosphere of coffee and the inka nut. The later two fungi had so far been recorded by concomitant morphological and molecular analyses only from tropical islands, A. herrerae from Cuba in the Golf of Mexico and A. fragilissima from New Caledonia in the southwest Pacific Ocean close to Australia. In this study, the ITS region of A. herrerae was analyzed for the first time and deposited in the public databases. In total, we already recovered fourteen Acaulospora species from coffee and inka nut plantations in San Martín State of Peru, suggesting that Acaulospora species are frequent and beneficial symbionts in coffee and inka nut roots in San Martín State of Peru

Viscospora peruviscosa, a new fungus in the Glomeraceae from a plantation of Theobroma cacao in Peru

A new fungus, Viscospora peruviscosa, was detected in a Theobroma cacao plantation in the Huallaga province of San Martín State in Peru.The fungus was propagated in the greenhouse on Sorghum vulgare and Brachiaria brizantha. The fungus is similar to V. viscosa as it has two spore wall layers and also a viscose outer spore surface, but its spores are smaller ((30-) 44-56 (-65) × (25-) 44-54 μm) and the subtending hyphae generally are more pronounced funnel-shaped. Also, the walls of the spores and subtending hyphae are thinner than in V. viscosa. Phylogenetically, both species form two well separated sister clades in the genus Viscospora. Based on the partial nrDNA gene, the two species have 90-91% maximum identity (MI). So far, the fungus is only known from the cacao plantation in Huallaga. No environmental sequences in the public data bases suggest that the fungus has already been found elsewhere in the neotropics or worldwide. This is the second species in the genus Viscospora (Glomeraceae) described, hence Viscospora is no longer monospecific

Propagation of Theobroma cacao by rooted cuttings in mini-tunnels

Cacao is an economically important crop that is currently planted in Asia, Africa, and America. Cuttings is a technique of vegetative propagation suitable for the conservation of selected desirable characteristics in cacao trees. The objective of this study was to evaluate the rooting of cacao cuttings in mini-tunnels with different doses of indole-3-butyric acid (IBA) to obtain a simple and viable vegetative propagation protocol. The experiment was carried out under a completely randomized design (CRD). Cuttings 5 to 7 cm long were collected from the middle area of cacao tree crowns and treated with doses of 0, 1000, 2000, and 3000 ppm of IBA; then they were placed in Jiffy© pellets and set to root in plastic-covered mini-tunnels with fog irrigation. The results indicate that treatments with 0 and 1000 ppm of IBA produced the highest values in survival (100%, both treatments) and rooting percentage (87.7 and 90.0%, respectively) as well as number and length of roots (4.3 roots-4.21 cm in length and 4.5 roots-5.32 cm in length, respectively); likewise, cuttings treated with 0 ppm rooted after 24–40 days, followed by doses of 1000 ppm (24–46 days). All rooted cuttings without IBA (0 ppm) achieved 100% acclimatization in nursery. In general, the best results were obtained without IBA application (Control 0 ppm) in all the parameters evaluated, similar to those obtained with the application of 1000 ppm IBA; these results indicate the success and efficiency of the vegetative propagation protocol proposed in this study

Response of the transcription factor BABY BOOM of Arabidopsis thaliana L. in the formation of embryogenic calluses of cocoa leaves (Theobroma cacao L.)

Cocoa (Theobroma cacao L.) is one of the most important economic crops worldwide. The propagation of elite varieties of cocoa has been achieved through somatic embryogenesis, but still one of the main limitations is the low rates of embryo formation, which is a genotype-dependent trait. Manipulation of transcription factors (TFs) such as BABY BOOM (BBM) promotes the transition of cocoa somatic cells from the vegetative to the embryonic state. This work validated the use of clonal cocoa leaves cv. IMC-67 to induce somatic embryogenesis, overcoming their recalcitrant limitation with the help of the introduction of TF-BBM from Arabidopsis thaliana (AtBBM). The vectors were constructed by the Gateway system using the donor vector pENTR/D-TOPO and the expression vector pk7WG2. The overexpression vector pk7WG2:AtBBM was obtained, allowing successful transformation into Agrobacterium tumefaciens GV3101. The AtBBM gene was characterized (1755 base pairs), and its expression was observed in the formation of embryogenic calluses in cocoa leaves. Overexpression of AtBBM allowed the obtainment of a 92% response in the formation of embryogenic callus in cocoa leaves with Agrobacterium-mediated vacuum infiltration and overexpression of the pk7WG2:AtBBM vector. This high transformation efficiency reached with the insertion of the overexpression vector provides validation of transient response of the TF AtBBM in the formation of embryogenic calluses in cocoa leaves of the IMC-67 clone. Through this methodology, it is possible to continue with studies of gene overexpression, insertion, silencing, and gene editing in Peruvian cocoa

Estudios globales sobre el cadmio en relación con Theobroma cacao: Un análisis bibliométrico desde Scopus (1996 -2020)

The maximum cadmium tolerance standards were established by the European Union in 2014, for the importation of cocoa-based products, causing concern in the countries. Global studies on Theobroma cacao research related to cadmium activity in the atmosphere were analyzed. Bibliometric analyses in R and VOSviewer programs were used to examine 64 documents published in the Scopus database according to keywords. We identified 811 keywords in the co-occurrence of terms, 5 thematic groups in the bibliographic coupling, 20 institutions as most important affiliations, 20 countries of origin of corresponding authors, 112 institutions in co-authorship network of which 5 are in primary documents, and two groups in thematic similarity in co-citation of documents. The United States leads the scientific production with 11 papers, followed by Colombia (8) and Ecuador (7). In 1996, the first scientific article was registered for the network, with increases of up to 11 publications by 2020. In conclusion, the need to strengthen and create more research networks between countries, institutions, authors, and co-authors is evident. It is hoped that the results will allow a comprehensive unraveling of the cadmium-cocoa research trajectory, while at the same time yielding new prospective research.En el año 2014, la Unión Europea impuso estándares máximos de tolerancia en cadmio, para la importación de productos a base de cacao, causando preocupación en los países. Se analizó estudios globales referidos a investigaciones en Theobroma cacao, relacionados con la actividad del cadmio en la atmósfera. Se utilizaron análisis bibliométricos en los programas R y VOSviewer, para examinar 64 documentos publicados en la base de datos Scopus según palabras clave. Se identificaron 811 palabras clave en coocurrencias de términos, 5 grupos temáticos en acoplamiento bibliográfico, 20 instituciones como afiliaciones más importantes, 20 países de procedencia de autores corresponsales, 112 instituciones en red de coautoría de los cuales 5 están en documentos primarios, y dos grupos en similaridad temática en co-citación de documentos. Estados Unidos lidera la producción científica con 11 documentos, seguido de Colombia (8) y Ecuador (7). En 1996 se registró el primer artículo científico para la red, con incrementos de hasta 11 publicaciones al 2020. En conclusión, se evidencia la necesidad de fortalecer y crear más redes de investigaciones entre países, instituciones, autores y coautores. Se espera que los resultados permitan desentrañar de manera integral la trayectoria de investigaciones cadmio-cacao, al tiempo que arrojen nuevas investigaciones prospectivas

Estudios globales sobre el cadmio en relación con Theobroma cacao: Un análisis bibliométrico desde Scopus (1996 -2020)

En el año 2014, la Unión Europea impuso estándares máximos de tolerancia en cadmio, para la importación de productos a base de cacao, causando preocupación en los países. Se analizó estudios globales referidos a investigaciones en Theobroma cacao, relacionados con la actividad del cadmio en la atmósfera. Se utilizaron análisis bibliométricos en los programas R y VOSviewer, para examinar 64 documentos publicados en la base de datos Scopus según palabras clave. Se identificaron 811 palabras clave en coocurrencias de términos, 5 grupos temáticos en acoplamiento bibliográfico, 20 instituciones como afiliaciones más importantes, 20 países de procedencia de autores corresponsales, 112 instituciones en red de coautoría de los cuales 5 están en documentos primarios, y dos grupos en similaridad temática en co-citación de documentos. Estados Unidos lidera la producción científica con 11 documentos, seguido de Colombia (8) y Ecuador (7). En 1996 se registró el primer artículo científico para la red, con incrementos de hasta 11 publicaciones al 2020. En conclusión, se evidencia la necesidad de fortalecer y crear más redes de investigaciones entre países, instituciones, autores y coautores. Se espera que los resultados permitan desentrañar de manera integral la trayectoria de investigaciones cadmio-cacao, al tiempo que arrojen nuevas investigaciones prospectivas

Fungal Systematics and Evolution: FUSE 8

In this 8th contribution to the Fungal Systematics and Evolution series published by Sydowia, the authors formally describe 11 species: Cortinarius caryae, C. flavolilacinus, C. lilaceolamellatus, C. malodorus, C. olivaceolamellatus, C. quercophilus, C. violaceoflavescens, C. viridicarneus, Entoloma meridionale (Agaricales), Hortiboletus rupicapreus (Boletales), and Paraglomus peruvianum (Paraglomerales). The following new country records are reported: Bolbitius callistus (Agaricales) from Russia and Hymenoscyphus equiseti (Helotiales) from Sweden. Hymenoscyphus equiseti is proposed as a new combination for Lanzia equiseti, based on ITS and LSU sequence data in combination with morphological study