Abstract:

The legume Arachis hypogaea, commonly known as peanut or groundnut, is a very important food crop throughout the tropics and sub-tropics. The genus is endemic to South America being mostly associated with the savannah-like Cerrado. All species in the genus are unusual among legumes in that they produce their fruit below the ground. This profoundly influences their biology and natural distributions. The species occur in diverse habitats including grasslands, open patches of forest and even in temporarily flooded areas. Based on a number of criteria, including morphology and sexual compatibilities, the 80 described species are arranged in nine infrageneric taxonomic sections. While most wild species are diploid, cultivated peanut is a tetraploid. It is of recent origin and has an AABB-type genome. The most probable ancestral species are Arachis duranensis and Arachis ipae¨nsis, which contributed the A and B genome components, respectively. Although cultivated peanut is tetraploid, genetically it behaves as a diploid, the A and B chromosomes only rarely pairing during meiosis. Although morphologically variable, cultivated peanut has a very narrow genetic base. For some traits, such as disease and pest resistance, this has been a fundamental limitation to crop improvement using only cultivated germplasm. Transfer of some wild resistance genes to cultivated peanut has been achieved, for instance, the gene for resistance to root-knot nematode. However, a wider use of wild species in breeding has been hampered by ploidy and sexual incompatibility barriers, by linkage drag, and historically, by a lack of the tools needed to conveniently confirm hybrid identities and track introgressed chromosomal segments. In recent years, improved knowledge of species relationships has been gained by more detailed cytogenetic studies and molecular phylogenies. This knowledge, together with new tools for genetic and genomic analysis, will help in the more efficient use of peanut’s genetic resources in crop improvement.

Author affiliation: Bertioli, David J.. Universidade Do Brasilia; Brasil. Universidade Católica de Brasília; Brasil

Author affiliation: Seijo, Jose Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina

Author affiliation: Freitas, Fabio O.. Embrapa Agroindustrial Tropical - CNPAT; Brasil

Author affiliation: Valls, José F. M.. Embrapa Agroindustrial Tropical - CNPAT; Brasil

Author affiliation: Leal-Bertioli, Soraya C. M.. Embrapa Agroindustrial Tropical - CNPAT; Brasil

Author affiliation: Moretzsohn, Marcio C.. Embrapa Agroindustrial Tropical - CNPAT; Brasil

Abstract:

Apomixis, a clonal plant reproduction by seeds, is controlled in Paspalum spp. by a single and recombinally-blocked locus. Partial sequence analysis of the apomixis locus revealed structural features of heterochromatin: i.e. presence of repetitive elements, gene degeneration and de-regulation. To test the epigenetic control of apomixis, a study on the distribution of cytosine methylation at the apomixis locus and the effect of artificial DNA de-methylation on the mode of reproduction was undertaken in two apomictic Paspalum species. The 5-Methyl cytosine distribution in the apomixis-controlling genomic region was studied in P. simplex by methylation-sensitive RFLP analysis and in P. notatum by FISH. The effect of DNA de-methylation was studied on the mode of reproduction of P. simplex by progeny test analysis of apomictic plants treated with the de-methylating agent 5’-Azacytidine. High level of cytosine methylation was detected at the apomixis-controlling genomic region in both species. By analyzing a total of 374 open pollination progenies we found that artificial de-methylation had little or no effect on apospory, whereas it induced a significant depression of parthenogenesis. Our results suggested that factors controlling repression of parthenogenesis might be inactivated in apomictic Paspalum by DNA methylation.

Author affiliation: Podio, Maricel. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Laboratorio de Biologia Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina

Author affiliation: Cáceres, María Emilia. CNR-Istituto di Bioscienze e Biorisorse; Italia

Author affiliation: Samoluk, Sergio Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina

Author affiliation: Seijo, Jose Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina

Author affiliation: Pessino, Silvina Claudia. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Laboratorio de Biologia Molecular; Argentina

Author affiliation: Ortiz, Juan Pablo Amelio. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Laboratorio de Biologia Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina

Author affiliation: Pupilli, Fulvio. CNR-Istituto di Bioscienze e Biorisorse; Italia

Abstract:

Turnera sidoides es un complejo poliploide (x= 7) de hierbas rizomatosas, perennes y distilas, que incluye cinco subespecies. Debido a la alta frecuencia de poliploides en el complejo, los estudios que se llevan a cabo actualmente están orientados a la comprensión de los mecanismos involucrados en el origen y establecimiento de los mismos a fin de proveer evidencias sobre los patrones evolutivos que operan en T. sidoides. En este trabajo se investiga la producción y frecuencia de microsporas no reducidas en plantas diploides provenientes de nueve poblaciones naturales pertenecientes a cuatro subespecies de T. sidoides, mediante el análisis del rango de variación del tamaño del polen y de la constitución de las esporadas. Los resultados obtenidos mostraron que casi todas las poblaciones estudiadas producen microsporas 2x y 4x, tanto en las flores brevistilas como en las longistilas. Asimismo, el análisis realizado aportó evidencias que sustentan la poliploidización sexual como uno de los mecanismos involucrados en el origen de los poliploides dentro del complejo. Se discute, además, el papel del polen no reducido en el establecimiento y la persistencia de los poliploides formados de novo en las poblaciones diploides de la especie

Analysis of the production and frequency of unreduced microspores in diploids of Turnera sidoides (Turneraceae). Turnera sidoides is a polyploid complex (x= 7) of dystilous perennial rhizomatous herbs that includes five subspecies. Owing to the high frequency of polyploids within the complex, ongoing studies in T. sidoides are focused on the understanding of the mechanisms involved in the origin and the establishment of polyploids in order to provide evidences of the evolutionary patterns in T. sidoides. In this report we investigate the occurrence and frequency of unreduced microspores in diploid plants from nine natural populations of four subspecies of T. sidoides by analyzing the range of variation of pollen volume and the constitution of the sporads. The results obtained showed that almost all the populations studied produced 2x and 4x microspores, both in short and long-styled floral morphs. Furthermore, the analysis performed provided evidences that support the hypothesis of sexual polyploidization as one of the mechanisms involved in the origin of polyploids within this species complex. The role of unreduced pollen in the establishment and persistence of newly formed polyploids within diploid populations of T. sidoides is also discussed.

Author affiliation: Panseri, Andrea Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina

Author affiliation: Seijo, José Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina

Author affiliation: Solis Neffa, Viviana Griselda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina

Abstract:

Background. Cultivated peanut, Arachis hypogaea is an allotetraploid of recent origin, with an AABB genome. In common with many other polyploids, it seems that a severe genetic bottle-neck was imposed at the species origin, via hybridisation of two wild species and spontaneous chromosome duplication. Therefore, the study of the genome of peanut is hampered both by the crop's low genetic diversity and its polyploidy. In contrast to cultivated peanut, most wild Arachis species are diploid with high genetic diversity. The study of diploid Arachis genomes is therefore attractive, both to simplify the construction of genetic and physical maps, and for the isolation and characterization of wild alleles. The most probable wild ancestors of cultivated peanut are A. duranensis and A. ipansis with genome types AA and BB respectively. Results. We constructed and characterized two large-insert libraries in Bacterial Artificial Chromosome (BAC) vector, one for each of the diploid ancestral species. The libraries (AA and BB) are respectively c. 7.4 and c. 5.3 genome equivalents with low organelle contamination and average insert sizes of 110 and 100 kb. Both libraries were used for the isolation of clones containing genetically mapped legume anchor markers (single copy genes), and resistance gene analogues. Conclusion. These diploid BAC libraries are important tools for the isolation of wild alleles conferring resistances to biotic stresses, comparisons of orthologous regions of the AA and BB genomes with each other and with other legume species, and will facilitate the construction of a physical map.

Author affiliation: Guimarães, Patricia M. Biotechnology Unit; Brasil

Author affiliation: Garsmeur, Olivier. Centre de Cooperation Internationale En Recherche Agronomique Pour Le Developperment; Francia

Author affiliation: Proite, Karina. Universidade do Brasília; Brasil. Biotechnology Unit; Brasil

Author affiliation: Leal Bertioli, Soraya C.M.. Biotechnology Unit; Brasil

Author affiliation: Seijo, José Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina

Author affiliation: Chaine, Christian. Centre de Cooperation Internationale En Recherche Agronomique Pour Le Developperment; Francia

Author affiliation: Bertioli, David J. Genomic Sciences And Biotechnology Program; Brasil

Author affiliation: D'Hont, Angelique. Centre de Cooperation Internationale En Recherche Agronomique Pour Le Developperment; Francia

Abstract:

The Somatic Embryogenesis Receptor Kinase (SERK) gene plays a fundamental role in somatic embryogenesis of angiosperms, and is associated with apomixis in Poa pratensis. The objective of this work was to isolate, characterize and analyze the expression patterns of SERK genes in apomictic and sexual genotypes of Paspalum notatum. A conserved 200-bp gene fragment was amplified from genomic DNA with heterologous primers, and used to initiate a chromosomal walking strategy for cloning the complete sequence. This procedure allowed the isolation of two members of the P. notatum SERK family; PnSERK1, which is similar to PpSERK1, and PnSERK2, which is similar to ZmSERK2 and AtSERK1. Phylogenetic analyses indicated that PnSERK1 and PnSERK2 represent paralogous sequences. Southern-blot hybridization indicated the presence of at least three copies of SERK genes in the species. qRT-PCR analyses revealed that PnSERK2 was expressed at significantly higher levels than PnSERK1 in roots, leaves, reproductive tissues and embryogenic calli.Moreover, in situ hybridization experiments revealed that PnSERK2 displayed a spatially and chronologically altered expression pattern in reproductive organs of the apomictic genotype with respect to the sexual one. PnSERK2 is expressed in nucellar cells of the apomictic genotype at meiosis, but only in the megaspore mother cell in the sexual genotype. Therefore, apomixis onset in P. notatum seems to be correlated with the expression of PnSERK2 in nucellar tissue.

Author affiliation: Podio, Maricel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina; Universidad Nacional de Rosario. Facultad de Cs.agrarias. Laboratorio de Biologia Molecular; Argentina;

Author affiliation: Felitti, Silvina Andrea. Universidad Nacional de Rosario. Facultad de Cs.agrarias. Laboratorio de Biologia Molecular; Argentina;

Author affiliation: Siena, Lorena Adeli. Universidad Nacional de Rosario. Facultad de Cs.agrarias. Laboratorio de Biologia Molecular; Argentina;

Author affiliation: Delgado Benarroch, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina; Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina;

Author affiliation: Mancini, Micaela. Universidad Nacional de Rosario. Facultad de Cs.agrarias. Laboratorio de Biologia Molecular; Argentina;

Author affiliation: Seijo, Jose Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina;

Author affiliation: Gonzalez, Ana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina;

Author affiliation: Pessino, Silvina Claudia. Universidad Nacional de Rosario. Facultad de Cs.agrarias. Laboratorio de Biologia Molecular; Argentina;

Author affiliation: Ortiz, Juan Pablo Amelio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina; Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina; Universidad Nacional de Rosario. Facultad de Cs.agrarias. Laboratorio de Biologia Molecular; Argentina;

Abstract:

The cytogenetic characterization of Arachis species is useful for assessing the genomes present in this genus, for establishing the relationship among their representatives and for understanding the variability in the available germplasm. In this study, we used fluorescence in situ hybridization (FISH) to examine the distribution patterns of heterochromatin and rDNA genes in 12 Brazilian accessions of five species of the taxonomic section Arachis. The heterochromatic pattern varied considerably among the species: complements with centromeric bands in all of the chromosomes (A. hoehnei) and complements completely devoid of heterochromatin (A. gregoryi, A. magna) were observed. The number of 45S rDNA loci ranged from two (A. gregoryi) to eight (A. glandulifera), while the number of 5S rDNA loci was more conserved and varied from two (in most species) to four (A. hoehnei). In some species one pair of 5S rDNA loci was observed adjacent to 45S rDNA loci. The chromosomal markers revealed polymorphism in the three species with more than one accession (A. gregoryi, A. magna and A. valida) that were tested. The previous genome assignment for each of the species studied was confirmed, except for A. hoehnei. The intraspecific variability observed here suggests that an exhaustive cytogenetic and taxonomic analysis is still needed for some Arachis species.

Author affiliation: Custodio, Adriana Regina. Universidade Federal de Santa Catarina. Centro de Ciências Agrárias; Brasil. Embrapa Genetic Resources and Biotechnology; Brasil

Author affiliation: Seijo, Jose Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina

Author affiliation: Montenegro Valls, Hosé Francisco. Embrapa Genetic Resources and Biotechnology; Brasil

Abstract:

Chromosome markers were developed for Arachis glandulifera using fluorescence in situ hybridization (FISH) of the 5S and 45S rRNA genes and heterochromatic 4'-6-diamidino-2-phenylindole (DAPI) positive bands. We used chromosome landmarks identified by these markers to construct the first Arachis species ideogram in which all the homologous chromosomes were precisely identified. The comparison of this ideogram with those published for other Arachis species revealed very poor homeologies with all A and B genome taxa, supporting the special genome constitution (D genome) of A. glandulifera. Genomic affinities were further investigated by dot blot hybridization of biotinylated A. glandulifera total DNA to DNA from several Arachis species, the results indicating that the D genome is positioned between the A and B genomes

Author affiliation: Robledo Dobladez, Germán Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina

Author affiliation: Seijo, José Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina

Abstract:

Aim: To analyse the current geographical structure of chloroplast DNA variation in the Turnera sidoides L. complex in order to establish historical biogeographical hypotheses for the mid‐latitude South American lowlands. During the Quaternary, the climate shifted from tropical humid to cold dry, and the vegetation cover has not been stable. The consequences of these processes on the current distribution of the vegetation of this area have received very little attention. Location: The mid‐latitude South American lowlands extend between c. 20 and 40°S and include Uruguay, northern, central and eastern Argentina, southern Brazil, and parts of southern Paraguay and Bolivia. They are surrounded by higher‐elevation systems. Methods: Turnera sidoides is a well‐studied polyploid complex of perennial rhizomatous herbs occurring throughout the area of interest. We analysed 321 individuals from 79 populations of the five recognized subspecies. We also included progenies from artificial crosses in order to analyse chloroplast inheritance. After screening sequences for four non‐coding chloroplast DNA regions, the trnL–trnF spacer was selected to characterize the collection. Results: Three haplotypes can be easily identified, with each differing from the others in two independent characters. A clear geographic structure is revealed when haplotypes are plotted for the complex as a whole regardless of subspecies and cytotype. Three distinct regions can be identified. Main conclusions: We propose three putative refugial areas for the Turnera sidoides complex, which are associated with the orographical systems of the region. Ravines and slopes in the Haedo Cuchilla system in northern Uruguay, the elevations of the western side of the area in Argentina, and the eastern Serranías system in south‐eastern Uruguay may each have served as refugia in which the A, B and C haplotypes became fixed during the drier climatic phases. Biogeographical patterns in the area covered by T. sidoides, particularly east of the Uruguay River, have not previously been analysed from a historical perspective. Location  The mid‐latitude South American lowlands extend between c. 20 and 40°S and include Uruguay, northern, central and eastern Argentina, southern Brazil, and parts of southern Paraguay and Bolivia. They are surrounded by higher‐elevation systems. Methods  Turnera sidoides is a well‐studied polyploid complex of perennial rhizomatous herbs occurring throughout the area of interest. We analysed 321 individuals from 79 populations of the five recognized subspecies. We also included progenies from artificial crosses in order to analyse chloroplast inheritance. After screening sequences for four non‐coding chloroplast DNA regions, the trnL–trnF spacer was selected to characterize the collection. Results  Three haplotypes can be easily identified, with each differing from the others in two independent characters. A clear geographic structure is revealed when haplotypes are plotted for the complex as a whole regardless of subspecies and cytotype. Three distinct regions can be identified. Main conclusions  We propose three putative refugial areas for the Turnera sidoides complex, which are associated with the orographical systems of the region. Ravines and slopes in the Haedo Cuchilla system in northern Uruguay, the elevations of the western side of the area in Argentina, and the eastern Serranías system in south‐eastern Uruguay may each have served as refugia in which the A, B and C haplotypes became fixed during the drier climatic phases. Biogeographical patterns in the area covered by T. sidoides, particularly east of the Uruguay River, have not previously been analysed from a historical perspective.

Author affiliation: Speranza, Pablo R.. Universidad de la República; Uruguay

Author affiliation: Seijo, José Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; Argentina

Author affiliation: Grela, Iván A.. Universidad de la República; Uruguay

Author affiliation: Solis Neffa, Viviana Griselda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina

Abstract:

Chromosome studies were carried out on 5 Argentinian species of Stemodia. First chromosome counts are presented for S. ericifolia (2n=22), S. lanceolata (2n=22), S. stricta (2n=44) and S. hyptoides (2n=66), while the number 2n=22 of S. verticillata is confirmed. These numbers constitute the first reports for South American species of Stemodia. In addition, the karyograms of S. lanceolata and S. verticillata are the first descriptions for the genus. Diploid species showed regular meiotic behaviour and pollen viability was high in all the accessions analysed. These results suggest that 2 different mechanisms would be implicated in chromosome diversification of Stemodia. The first one implicates variation in genome size with karyotype formulae conservation and the second, polyploidy. Chromosome data provided here are discussed in relation to growth habit, morphological characters and taxonomic position of the species.

Author affiliation: Sosa, María de las Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina

Author affiliation: Seijo, José Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina

Abstract:

Rhizomatosae is a taxonomic section of the South American genus Arachis, whose diagnostic character is the presence of rhizomes in all its species. This section is of particular evolutionary interest because it has three polyploid (A. pseudovillosa, A. nitida and A. glabrata, 2n = 4x = 40) and only one diploid (A. burkartii, 2n = 2x = 20) species. The phylogenetic relationships of these species as well as the polyploidy nature and the origin of the tetraploids are still controversial. The present study provides an exhaustive analysis of the karyotypes of all rhizomatous species and six closely related diploid species of the sections Erectoides and Procumbentes by cytogenetic mapping of DAPI/CMA heterochromatin bands and 5S and 18–26S rDNA loci. Chromosome banding showed variation in the DAPI heterochromatin distribution pattern, which, together with the number and distribution of rDNA loci, allowed the characterization of all species studied here. The bulk of chromosomal markers suggest that the three rhizomatous tetraploid species constitute a natural group and may have at least one common diploid ancestor. The cytogenetic data of the diploid species analyzed evidenced that the only rhizomatous diploid species—A. burkartii—has a karyotype pattern different from those of the rhizomatous tetraploids, showing that it is not likely the genome donor of the tetraploids and the non-monophyletic nature of the section Rhizomatosae. Thus, the tetraploid species should be excluded from the R genome, which should remain exclusively for A. burkartii. Instead, the karyotype features of these tetraploids are compatible with those of different species of the sections Erectoides and Procumbentes (E genome species), suggesting the hypothesis of multiple origins of these tetraploids. In addition, the polyploid nature and the group of diploid species closer to the tetraploids are discussed.

Author affiliation: Ortiz, Alejandra Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina

Author affiliation: Robledo Dobladez, Germán Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina

Author affiliation: Seijo, José Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina

Author affiliation: Valls, José Francisco Montenegro. Embrapa Recursos Genéticos e Biotecnologia; Brasil

Author affiliation: Lavia, Graciela Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina