Summary Background and aims : The taxonomic location of the Potentilleae tribe species in Argentina was highly controversial and intensely debated by various authors, in such a way that some merged genera, while others recognized them as valid taxonomic entities. These conflicts show the need for an updated taxonomic treatment. The objective of this work is to present an updated taxonomic synopsis of the Potentilleae in Argentina. M&M: Taxonomic data from the literature were collected, including phylogenetic studies, and specimens of the Potentilleae tribe of Argentine and foreign herbaria were analyzed; in addition to material collected in the field. Results and Conclusions : In Argentina, 3 genera with 5 species and 2 forms were recognized for the Potentilleae tribe, differing in a dichotomous key by vegetative, floral and carpological characters. The name of the authors of a species was legitimized and a form was lectotypified. The distribution of one species was broadened and the presence of another was rectified. The Potentilleae inhabit trails, pastures, herbaceous stratum of the Yungas, in open spaces and at elevations from 600-2600 meters above sea level. They grow in riparian environments and in abandoned crops.

Resumen Introducción y objetivos : La ubicación taxonómica de las especies de la tribu Potentilleae en Argentina fue muy controvertida e intensamente debatida por varios autores, de tal manera que algunos fusionaron géneros, mientras que otros los reconocieron como entidades taxonómicas válidas. Estos conflictos muestran la necesidad de realizar un tratamiento taxonómico actualizado. El objetivo de este trabajo es presentar una sinopsis taxonómica actualizada de las Potentilleae en Argentina. M&M : Se recopilaron datos taxonómicos de la literatura, incluidos estudios filogenéticos, y se analizaron especímenes de la tribu Potentilleae de herbarios argentinos y extranjeros; además de material colectado a campo. Resultados y Conclusiones : En Argentina, se reconocieron 3 géneros con 5 especies y 2 formas para la tribu Potentilleae, diferenciándose en una clave dicotómica por caracteres vegetativos, florales y carpológicos. Se legitimó el nombre de los autores de una especie y se lectotipificó una forma. Se amplió la distribución de una especie y se ratificó la presencia de otra. Las Potentilleae habitan en senderos, pastizales, estrato herbáceo de las Yungas, en ambientes descampados y en elevaciones desde los 600-2600 msnm. Crecen en ambientes ribereños y en cultivos abandonados.

Duchesnea indica (Andrews) Focke (Rosaceae) is a species with numerous genotypes, present in different environments, and without register of associations with any pseudococcidae. From the analysis of specimens from the Banco de Germoplasma de Frutilla - Universidad Nacional de Tucumán (BGF-UNT), the presence of individuals of the species Ferrisia meridionalis Williams was observed in vegetative pieces and reproductive organs of plants of the genotype D. indica f. albocaput. We report the association between F. meridionalis and D. indica for the first time.

Duchesnea indica (Andrew) Focke (Rosaceae) es una especie con numerosos genotipos, presente en diferentes ambientes, y sin registro de asociaciones con pseudocóccidos. En ejemplares provenientes del Banco de Germoplasma de Frutilla de la Universidad Nacional de Tucumán (BGF-UNT) se observó la presencia de individuos de Ferrisia meridionalis Williams en piezas vegetativas y órganos reproductivos de plantas del genotipo D. indica f. albocaput. Se da a conocer por primera vez la asociación entre F. meridionalis y D. indica.

ABSTRACT Sugarcane orange rust caused by Puccinia kuehnii has recently become an important disease in sugarcane crops and its spread is causing great concern to growers. In this study, we analyzed spores from symptomatic orange rust sugarcane leaves collected in multiple locations in Cuba in a 4-year-period in order to characterize morphological traits of P. kuehnii, establish an adequate molecular technique to characterize it, and determine its infection court in sugarcane. Orange rust caused by P. kuehnii was confirmed by polymerase chain reaction (PCR) and morphological characterization. AFLP markers detected high diversity in P. kuenhnii samples. Sequencing of rDNA regions, as expected, did not reveal differences and SSR markers designed for P. melanocephala could not be transferred to P. kuehnii. In addition to stomata, entry through prickles was also detected as a new infection court in sugarcane. Although the presence of pustules on the adaxial leaf surface was frequently detected, no clear correlation between this presence and density of stomata and/or prickles was found.

The genus Duchesnea includes two species originally from India: D. indica and D. chrysantha. In Northwestern Argentina the monitoring of wild strawberry-like species was carried out; during 2002-2016, many populations of D. indica and none of D. chrysantha were discovered. Red- and white-fruited plants of D. indica were collected from disturbed areas and ex situ conserved in green-house and in nursery conditions. Were also consulted materials from different national and international herbaria, and we only found reports of D. indica with red fruit for Argentina. In the present work, we report for the frst time the presence of D. indica f. albocaput in Argentina and South America, cohabiting with populations of D. indica f. indica in the underwoods of Tucumán. This finding broadens the distribution range of D. indica f. albocaput, cited as endemic to Japan by Naruhashi 1992. The morphological and anatomical characters of the two botanical forms of D. indica (red fruit genotypes and white fruit genotypes) are also presented: fruit color, number of leafets, and crystal form.

Primer informe de Duchesnea indica f. albocaput (Rosaceae) en Noroeste de Argentina. El género Duchesnea incluye dos especies originarias de India: D. indica y D. chrysantha. Durante el período 2002-2016, se realizaron monitoreos de especies silvestres relacionadas con la frutilla cultivada en el Noroeste Argentino y se encontraron numerosas poblaciones de D. indica pero ninguna de D. chrysantha. Plantas de D. indica con frutos rojos y plantas con frutos blancos fueron colectadas y conservadas ex situ, en cámaras bajo condiciones controladas y en invernaderos a campo. Se consultaron también materiales de diferentes herbarios nacionales e internacionales, y solo se encontraron reportes de ejemplares de D. indica de frutos rojos para Argentina. En el presente trabajo se reporta por primera vez para Argentina y Sudamérica, la presencia de poblaciones de D. indica f. albocaput, co-habitando con poblaciones de D. indica f. indica en sotobosques de Tucumán. Con esta cita se amplía el rango de distribución de D. indica f. albocaput, citada como endémica para Japón. Se presentan además, las características morfo-anatómicas distintivas de ambas formas botánicas de D. indica (genotipos de frutos rojos y genotipos de frutos blancos): color del fruto, número de foliolos, y forma de cristales.

ABSTRACT Citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), has an important economic impact on the citrus industry. Extensive information is available about the disease but, nevertheless, the study of plant-pathogen interactions could provide new information in the understanding of citrus canker disease. A new isolate has been identified, Xcc AT, which has a high genetic similarity (> 90 %) to the virulent Xcc T strain based on genetic clustering analyses of the rep-PCR fingerprinting patterns, but it does not produce cankerous lesions in Citrus limon. In this study, we compared C. limon responses to Xcc AT and to the virulent Xcc T strain at both histological and transcriptional levels. Histologically, leaves inoculated with Xcc AT exhibited neither a typical disordering of the spongy mesophyll, nor a swelling of epidermis. A particular content (undetermined) was also found in mesophyll cells near the stomata, together with increased starch accumulation. The transcriptomic profiles were compared by cDNA-AFLP technique. A total of 121 fragments derived from transcript (TDF) were either specifically induced or repressed by the isolates, and 62 were sequenced. Analysis of global expression identified different classes of genes known to be involved in plant-pathogen interactions. This study constitutes the first approach of the specific interaction between the avirulent Xcc AT isolate and C. limon.