Evidence Of Allopolyploidy In Urochloa Humidicola Based On Cytological Analysis And Genetic Linkage Mapping

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The African species Urochloa humidicola (Rendle) Morrone & Zuloaga (syn. Brachiaria humidicola (Rendle) Schweick.) is an important perennial forage grass found throughout the tropics. This species is polyploid, ranging from tetra to nonaploid, and apomictic, which makes genetic studies challenging; therefore, the number of currently available genetic resources is limited. The genomic architecture and evolution of U. humidicola and the molecular markers linked to apomixis were investigated in a full-sib F-1 population obtained by crossing the sexual accession H031 and the apomictic cultivar U. humidicola cv. BRS Tupi, both of which are hexaploid. A simple sequence repeat (SSR)-based linkage map was constructed for the species from 102 polymorphic and specific SSR markers based on simplex and double-simplex markers. The map consisted of 49 linkage groups (LGs) and had a total length of 1702.82 cM, with 89 microsatellite loci and an average map density of 10.6 cM. Eight homology groups (HGs) were formed, comprising 22 LGs, and the other LGs remained ungrouped. The locus that controls apospory (apo-locus) was mapped in LG02 and was located 19.4 cM from the locus Bh027.c.D2. In the cytological analyses of some hybrids, bi-to hexavalents at diakinesis were observed, as well as two nucleoli in some meiocytes, smaller chromosomes with preferential allocation within the first metaphase plate and asynchronous chromosome migration to the poles during anaphase. The linkage map and the meiocyte analyses confirm previous reports of hybridization and suggest an allopolyploid origin of the hexaploid U. humidicola. This is the first linkage map of an Urochloa species, and it will be useful for future quantitative trait locus (QTL) analysis after saturation of the map and for genome assembly and evolutionary studies in Urochloa spp. Moreover, the results of the apomixis mapping are consistent with previous reports and confirm the need for additional studies to search for a co-segregating marker.11Brazilian Agricultural Research Corporation (Embrapa)Brazilian National Council for Scientific and Technological Development (CNPq) [478262/2004-3, 502336/2005-6, 482458/2007-0]State of Sao Paulo Research Foundation (FAPESP) [2005/51010-0, 2008/52197-4]Foundation for Science and Technological Development of the State of Mato Grosso do Sul (Fundect)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)FAPESP [2007/57022-5, 2010/50032-8]Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES - EMBRAPA Program)CNPq [304914/2010-0]CNPqConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Characterization of 12 microsatellite loci from an enriched genomic library in polyploid Tibouchina pulchra Cogn. (Melastomataceae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Tibouchina pulchra is a common hermaphroditic canopy tree of the Melastomataceae in the Brazilian Atlantic Rain Forest that is important for bee communities, reforestation, soil and air bio-indication and urban ornamentation. Twelve polymorphic microsatellite markers were isolated and characterized in 89 genotypes of T. pulchra from two populations of Ubatuba and Sao Luis do Paraitinga municipalities (Sao Paulo, Brazil). The number of alleles observed for each locus ranged from 4 to 31 with an average of 12 alleles per locus. The polymorphism information content varied between 0.51 and 0.92 (average 0.74) and the discriminating power (D) ranged from 0.66 to 0.99 (average 0.87). These microsatellite markers will be useful for assessing genetic studies, conservation management, and ecological and phylogenetic evaluations.21193196Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [Processo 03/12595-7

Microsatellite markers for the endangered orchids Cattleya labiata Lindl. and C-warneri T. Moore (Orchidaceae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)In this study, we developed a new set of microsatellite markers for endangered Cattleya labiata and Cattleya warneri. Also the first microsatellite loci for Cattleya, these markers can be useful for studies in the conservation genetics of these species. Twenty-one new microsatellite primers pairs were characterized by cloning an enriched library, and two libraries were obtained by cloning inter-simple sequence repeats. Thirteen polymorphic primers were found, and the remaining eight were monomorphic for both species. Our results indicate that these new microsatellite markers have the potential to be used as a tool for studying the genetic diversity of C. labiata and C. warneri and for future studies focusing mating systems and the detection of hybrids.53791794Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundacao de Amparo a Pesquisa do Estado da Bahia [FAPESB T.O. PNX0014/2009]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq [481715/2010-0, 141325/2009-7]Fundacao de Amparo a Pesquisa do Estado da Bahia [FAPESB T.O. PNX0014/2009

Isolation and characterization of microsatellite markers for Brachiaria brizantha (Hochst. ex A. Rich.) Stap

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The first set of nuclear simple sequence repeat (SSR) loci for Brachiaria brizantha (Hochst. ex A. Rich.) Stap is described. A microsatellite-enriched library was constructed and 19 loci were characterized. About 13 SSR loci were found to be polymorphic and across-taxa amplification tests showed that six of them can be transferred to four other species of Brachiaria. This new SSR resource will be a powerful tool for population genetic studies of B. brizantha, for interspecific genetic studies within the genus Brachiaria, for mapping and for marker assisted selection in breeding.10618731876Brazilian Agricultural Research Corporation (Embrapa)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Foundation for Science and Technological Development of the State of Mato Grosso do Sul (Fundect)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Development of microsatellite markers for Brachiaria humidicola (Rendle) Schweick

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)We describe the first panel of nuclear simple sequence repeats (SSRs) loci for Brachiaria humidicola (Rendle) Schweick., a warmseason grass with facultative apomixis, variation in ploidy levels (6X-9X), and important forage grass species in the Tropics. Of 38 pairs of primers obtained by using an enriched-library methodology, 27 revealed polymorphism in 58 accessions of the Germplasm Collection of B. humidicola held at Embrapa Beef Cattle, Brazil. Eleven loci amplified in B. dictyoneura, a closely related species with unclear taxonomic boundaries with B. humidicola. Transferability to other three Brachiaria species was also evaluated. The developed microsatellites are potentially useful for genetic studies of B. humidicola, as well as phylogenetic evaluations, conservation and breeding applications.11475479Brazilian Agricultural Research Corporation (EMBRAPA)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Foundation for Science and Technological Development of the State of Mato Grosso do Sul (FUNDECT)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Genetic variation in polyploid forage grass: Assessing the molecular genetic variability in the Paspalum genus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Background: Paspalum (Poaceae) is an important genus of the tribe Paniceae, which includes several species of economic importance for foraging, turf and ornamental purposes, and has a complex taxonomical classification. Because of the widespread interest in several species of this genus, many accessions have been conserved in germplasm banks and distributed throughout various countries around the world, mainly for the purposes of cultivar development and cytogenetic studies. Correct identification of germplasms and quantification of their variability are necessary for the proper development of conservation and breeding programs. Evaluation of microsatellite markers in different species of Paspalum conserved in a germplasm bank allowed assessment of the genetic differences among them and assisted in their proper botanical classification. Results: Seventeen new polymorphic microsatellites were developed for Paspalum atratum Swallen and Paspalum notatum Flugge, twelve of which were transferred to 35 Paspalum species and used to evaluate their variability. Variable degrees of polymorphism were observed within the species. Based on distance-based methods and a Bayesian clustering approach, the accessions were divided into three main species groups, two of which corresponded to the previously described Plicatula and Notata Paspalum groups. In more accurate analyses of P. notatum accessions, the genetic variation that was evaluated used thirty simple sequence repeat (SSR) loci and revealed seven distinct genetic groups and a correspondence of these groups to the three botanical varieties of the species (P. notatum var. notatum, P. notatum var. saurae and P. notatum var. latiflorum). Conclusions: The molecular genetic approach employed in this study was able to distinguish many of the different taxa examined, except for species that belong to the Plicatula group, which has historically been recognized as a highly complex group. Our molecular genetic approach represents a valuable tool for species identification in the initial assessment of germplasm as well as for characterization, conservation and successful species hybridization.14Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)[2006/61242-8]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [05/51010-0][2006/61242-8

Genetic diversity and population structure analysis of the tropical pasture grass Brachiaria humidicola based on microsatellites, cytogenetics, morphological traits, and geographical origin

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Brachiaria humidicola (Rendle) Schweick. is a warm-season grass commonly used as forage in the tropics. Accessions of this species were collected in eastern Africa and massively introduced into South America in the 1980s. Several of these accessions form a germplasm collection at the Brazilian Agricultural Research Corporation. However, apomixis, ploidy, and limited knowledge of the genetic basis of this germplasm collection have constrained breeding activities. The objectives of this work were to identify genetic variability in the Brazilian B. humidicola germplasm collection using microsatellite markers and to compare the results with information on the following: (1) collection sites of the accessions; (2) reproductive mode and ploidy levels; and (3) genetic diversity revealed by morphological traits. The evaluated germplasm population is highly structured into four major groups. The sole sexual accession did not group with any of the clusters. Genetic dissimilarities did not correlate with either geographic distances or genetic distances inferred from morphological descriptors. Additionally, the genetic structure identified in this collection did not correspond to differences in ploidy level. Alleles exclusive to either sexual or apomictic accessions were identified, suggesting that further evaluation of the association of these loci with apospory should be carried out.539698709Brazilian Agricultural Research Corporation (EMBRAPA) [02.05.2.10.00.02.01, 01.06.1.07.05.06.02]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Foundation for Science and Technological Development of the State of Mato Grosso do Sul (FUNDECT) [41/100165/2004]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Brazilian Agricultural Research Corporation (EMBRAPA) [02.05.2.10.00.02.01, 01.06.1.07.05.06.02]CNPq [482458/2007-0, 478262/2004-3, 307430/2007-3]FAPESP [2010/51010-0, 2007/57022-5, 2006/52953-8]Foundation for Science and Technological Development of the State of Mato Grosso do Sul (FUNDECT) [41/100165/2004

Understanding Genetic Diversity and Population Structure of a <i>Poa pratensis</i> Worldwide Collection through Morphological, Nuclear and Chloroplast Diversity Analysis

<div><p><i>Poa pratensis</i> L. is a forage and turf grass species well adapted to a wide range of mesic to moist habitats. Due to its genome complexity little is known regarding evolution, genome composition and intraspecific phylogenetic relationships of this species. In the present study we investigated the morphological and genetic diversity of 33 <i>P</i>. <i>pratensis</i> accessions from 23 different countries using both nuclear and chloroplast molecular markers as well as flow cytometry of somatic tissues. This with the aim of shedding light on the genetic diversity and phylogenetic relationships of the collection that includes both cultivated and wild materials. Morphological characterization showed that the most relevant traits able to distinguish cultivated from wild forms were spring growth habit and leaf colour. The genome size analysis revealed high variability both within and between accessions in both wild and cultivated materials. The sequence analysis of the <i>trn</i>L-F chloroplast region revealed a low polymorphism level that could be the result of the complex mode of reproduction of this species. In addition, a strong reduction of chloroplast SSR variability was detected in cultivated materials, where only two alleles were conserved out of the four present in wild accessions. Contrarily, at nuclear level, high variability exist in the collection where the analysis of 11 SSR loci allowed the detection of a total of 91 different alleles. A Bayesian analysis performed on nuclear SSR data revealed that studied materials belong to two main clusters. While wild materials are equally represented in both clusters, the domesticated forms are mostly belonging to cluster P2 which is characterized by lower genetic diversity compared to the cluster P1. In the Neighbour Joining tree no clear distinction was found between accessions with the exception of those from China and Mongolia that were clearly separated from all the others.</p></div