Abstract Coffee leaf rust (Hemileia vastatrix) is the most important disease in coffee crops around the world. Currently, there is limited knowledge about mass production methodologies and ex-situ infection of H. vastatrix that lead to the development of different health characterization studies of Coffea or disease phenotyping. In this context, the aim of this research was to develop a simple protocol for the mass production of coffee rust uredospores under controlled conditions and to determine their infection in coffee seedlings. Uredospores of H. vastatrix were collected from infected plants in the “Chontal” coffee-growing area in San Martín, Peru. The viability of uredospore germination was evaluated, and a uredospores suspension (2 x 105 uredospores/mL) was prepared to inoculate coffee seedlings. Incidence and sporulation rates were evaluated after 43 days of inoculation. During the multiplication process of H. vastatrix uredospores, using controlled conditions (23±1 °C, ≈ 80% relative humidity and photoperiod of 16 hours of light) under an innovative system, the first symptoms of chlorosis were observed on coffee leaves 20 days after inoculation. Our findings show a 100% incidence of inoculated coffee plants with an average of 54 mg of H. vastatrix uredospores per plant and a 1.38 x 10-1 mg/cm2 sporulation rate. Finally, here we report a protocol that allows mass multiplication of H. vastatrix uredospores under controlled conditions, that would be useful in any time for coffee leaf rust bioassays.

Abstract 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 onTheobroma cacaoresearch 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.

Resumen 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.

Resumo: O objetivo deste trabalho foi avaliar o balanço hormonal em fases da organogênese in vitro de ápices meristemáticos de sacha inchi (Plukenetia volubilis). Para as fases de estabelecimento e multiplicação, foi utilizado o meio de cultivo Murashige & Skoog (MS) com diferentes concentrações de benzilaminopurina (BAP) e ácido naftalenoacético (ANA). Para o enraizamento, o meio MS modificado foi suplementado com diferentes concentrações de ANA e ácido indolbutírico. A diferenciação dos ápices meristemáticos foi possível com a adição de 0,1 mg L-1 de BAP e 0,05 mg L-1 de ANA. O melhor desempenho do enraizamento de plântulas é obtido com a adição de 0,5 mg L-1 de ácido naftalenoacético e 2,0 mg L-1 de ácido indolbutírico.

Abstract: The objective of this work was to evaluate hormonal balance in the phases of the in vitro organogenesis of apical meristems of sacha inchi (Plukenetia volubilis). For the establishment and multiplication phases, Murashige & Skoog (MS) media, with different concentrations of benzylaminopurine (BAP) and naphthaleneacetic acid (NAA), were used. For rooting, modified MS media was supplemented with different concentrations of NAA and indolebutyric acid. The differentiation of apical meristems was possible with 0.1 mg L-1 BAP and 0.05 mg L-1 NAA. The best rooting of seedlings is obtained with 0.5 mg L-1 naphthaleneacetic acid and 2.0 mg L-1 indolebutyric acid.