Microsatellite In Aeschynomene Falcata (leguminosae): Diversity, Cross-amplification, And Chromosome Localization.

Aeschynomene falcata is an important forage species; however, because of low seed production, it is underutilized as forage species. Aeschynomene is a polyphyletic genus with a challenging taxonomic position. Two subgenera have been proposed, and it is suggested that Aeschynomene can be split in 2 genera. Thus, new markers, such as microsatellite sequences, are desirable for improving breeding programs for A. falcata. Based on transferability and in situ localization, these microsatellite sequences can be applied as chromosome markers in the genus Aeschynomene and closely related genera. Here, we report the first microsatellite library developed for this genus; 11 microsatellites were characterized, with observed and expected heterozygosities ranging from 0.0000 to 0.7143 and from 0.1287 to 0.8360, respectively. Polymorphic information content varied from 0.1167 to 0.7786. The departure from Hardy-Weinberg equilibrium may have resulted from frequent autogamy, which is characteristic of A. falcata. Of the 11 microsatellites, 9 loci were cross-amplified in A. brevipes and A. paniculata and 7 in Dalbergia nigra and Machaerium vestitum. Five of these 7 cross-amplified microsatellites were applied as probes during the in situ hybridization assay and 2 showed clear signals on A. falcata chromosomes, ensuring their viability as chromosome markers.1310390-

Microsatellite in Aeschynomene falcata (Leguminosae): Diversity, cross-amplification, and chromosome localization

Aeschynomene falcata is an important forage species; however, because of low seed production, it is underutilized as forage species. Aeschynomene is a polyphyletic genus with a challenging taxonomic position. Two subgenera have been proposed, and it is suggested that Aeschynomene can be split in 2 genera. Thus, new markers, such as microsatellite sequences, are desirable for improving breeding programs for A. falcata. Based on transferability and in situ localization, these microsatellite sequences can be applied as chromosome markers in the genus Aeschynomene and closely related genera. Here, we report the first microsatellite library developed for this genus; 11 microsatellites were characterized, with observed and expected heterozygosities ranging from 0.0000 to 0.7143 and from 0.1287 to 0.8360, respectively. Polymorphic information content varied from 0.1167 to 0.7786. The departure from Hardy-Weinberg equilibrium may have resulted from frequent autogamy, which is characteristic of A. falcata. Of the 11 microsatellites, 9 loci were cross-amplified in A. brevipes and A. paniculata and 7 in Dalbergia nigra and Machaerium vestitum. Five of these 7 cross-amplified microsatellites were applied as probes during the in situ hybridization assay and 2 showed clear signals on A. falcata chromosomes, ensuring their viability as chromosome markers1341039010397CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP471708/2010-02011/22215-3; 2010/19132-

Leaf-, panel- and latex-expressed sequenced tags from the rubber tree (Hevea brasiliensis) under cold-stressed and suboptimal growing conditions: the development of gene-targeted Functional markers for stress response.

Hevea brasiliensis is a native species of the Amazon Basin of South America and the primary source of natural rubber worldwide. Due to the occurrence of South American Leaf Blight disease in this area, rubber plantations have been extended to suboptimal regions. Rubber tree breeding is time-consuming and expensive, but molecular markers can serve as a tool for early valuation, thus reducing time and costs. In this work, we constructed six different cDNA libraries with the aim of developing gene-targeted molecular markers for the rubber tree. A total of 8,263 reads were assembled, generating 5,025 unigenes that were analyzed; 912 expressed sequence tags (ESTs) represented new transcripts, and two sequences were highly up-regulated by cold stress. These unigenes were scanned for microsatellite (SSR) regions and single nucleotide polymorphisms (SNPs). In total, 169 novel EST-SSR markers were developed; 138 loci were polymorphic in the rubber tree, and 98 % presented transferability to six other Hevea species. Locus duplication was observed in H. brasil-iensis and other species. Additionally, 43 SNP markers in 13 sequences that showed similarity to proteins involved in stress response, latex biosynthesis and developmental processes were characterized. cDNA libraries are a rich source of SSR and SNP markers and enable the identification of new transcripts. The new markers developed here will be a valuable resource for linkage mapping, QTL identification and other studies in the rubber tree and can also be used to evaluate the genetic variability of other Hevea species, which are valuable assets in rubber tree breeding

Microsatellite Markers For Studies With The Carnivorous Plant Philcoxia Minensis (plantaginaceae).

Microsatellite markers were developed for the critically endangered carnivorous species Philcoxia minensis (Plantaginaceae) for further population genetic studies aiming at its conservation. We identified 29 clones containing 40 microsatellites from a genomic enriched library. A total of 27 primer pairs were developed and evaluated in 30 individuals of a natural P. minensis population. Seventeen markers successfully presented amplification products within the expected size range, of which 12 were polymorphic. The expected and observed heterozygosities ranged from 0.03 to 0.65 and from 0.00 to 0.77, respectively. Positive transferability with the related species P. bahiensis was observed for the same 17 markers. The 12 polymorphic microsatellite markers are suitable for studies in genetic diversity and structure, mating system, and gene flow in P. minensis and also may be useful for similar issues regarding the related species P. bahiensis.

Microsatellite markers for studies with the carnivorous plant Philcoxia minensis (Plantaginaceae)

Premise of the study: Microsatellite markers were developed for the critically endangered carnivorous species Philcoxia minensis (Plantaginaceae) for further population genetic studies aiming at its conservation. Methods and Results: We identifi ed 29 clones containing 40 microsatellites from a genomic enriched library. A total of 27 primer pairs were developed and evaluated in 30 individuals of a natural P. minensis population. Seventeen markers successfully presented amplifi cation products within the expected size range, of which 12 were polymorphic. The expected and observed heterozygosities ranged from 0.03 to 0.65 and from 0.00 to 0.77, respectively. Positive transferability with the related species P. bahiensis was observed for the same 17 markers. Conclusions: The 12 polymorphic microsatellite markers are suitable for studies in genetic diversity and structure, mating system, and gene fl ow in P. minensis and also may be useful for similar issues regarding the related species P. bahiensis38CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informaçãoSem informação2012/12927-

Linkage disequilibrium and population structure in wild and cultivated populations of rubber tree (Hevea brasiliensis).

Abstract: Among rubber tree species, which belong to the Hevea genus of the Euphorbiaceae family, Hevea brasiliensis (Willd. ex Adr.de Juss.) Muell. Arg. is the main commercial source of natural rubber production worldwide. Knowledge of the population structure and linkage disequilibrium (LD) of this species is essential for the efficient organization and exploitation of genetic resources. Here, we obtained single-nucleotide polymorphisms (SNPs) using a genotyping-by-sequencing (GBS) approach and then employed the SNPs for the following objectives: (i) to identify the positions of SNPs on a genetic map of a segregating mapping population, (ii) to evaluate the population structure of a germplasm collection, and (iii) to detect patterns of LD decay among chromosomes for future genetic association studies in rubber tree. A total of 626 genotypes, including both germplasm accessions (368) and individuals from a genetic mapping population (254), were genotyped. A total of 77,660 and 21,283 SNPs were detected by GBS in the germplasm and mapping populations, respectively. The mapping population, which was previously mapped, was constructed with 1,062 markers, among which only 576 SNPs came from GBS, reducing the average interval between two adjacent markers to 4.4 cM. SNPs from GBS genotyping were used for the analysis of genetic structure and LD estimation in the germplasm accessions. Two groups, which largely corresponded to the cultivated and wild populations, were detected using STRUCTURE and via principal coordinate analysis. LD analysis, also using the mapped SNPs, revealed that non-random associations varied along chromosomes, with regions of high LD interspersed with regions of low LD. Considering the length of the genetic map (4,693 cM) and the mean LD (0.49 for cultivated and 0.02 for wild populations), a large number of evenly spaced SNPs would be needed to perform genome-wide association studies in rubber tree, and the wilder the genotypes used, the more difficult the mapping saturation

High-resolution genetic map and QTL analysis of growth-related traits of Hevea brasiliensis cultivated under suboptimal temperature and humidity conditions

Rubber tree (Hevea brasiliensis) cultivation is the main source of natural rubber worldwide and has been extended to areas with suboptimal climates and lengthy drought periods; this transition affects growth and latex production. High-density genetic maps with reliable markers support precise mapping of quantitative trait loci (QTL), which can help reveal the complex genome of the species, provide tools to enhance molecular breeding, and shorten the breeding cycle. In this study, QTL mapping of the stem diameter, tree height, and number of whorls was performed for a full-sibling population derived from a GT1 and RRIM701 cross. A total of 225 simple sequence repeats (SSRs) and 186 single-nucleotide polymorphism (SNP) markers were used to construct a base map with 18 linkage groups and to anchor 671 SNPs from genotyping by sequencing (GBS) to produce a very dense linkage map with small intervals between loci. The final map was composed of 1,079 markers, spanned 3,779.7 cM with an average marker density of 3.5 cM, and showed collinearity between markers from previous studies. Significant variation in phenotypic characteristics was found over a 59-month evaluation period with a total of 38 QTLs being identified through a composite interval mapping method. Linkage group 4 showed the greatest number of QTLs (7), with phenotypic explained values varying from 7.67 to 14.07%. Additionally, we estimated segregation patterns, dominance, and additive effects for each QTL. A total of 53 significant effects for stem diameter were observed, and these effects were mostly related to additivity in the GT1 clone. Associating accurate genome assemblies and genetic maps represents a promising strategy for identifying the genetic basis of phenotypic traits in rubber trees. Then, further research can benefit from the QTLs identified herein, providing a better understanding of the key determinant genes associated with growth of Hevea brasiliensis under limiting water conditions

Processamento auditivo: marcadores de tempo por habilidade auditiva

Model of study: descriptive study and cross. Purpose: to characterize the acquisition time of each hearing ability worked with children diagnosed with Disturbance of Central Auditory Processing, school age, from a speech therapy program pre-established, which lasted 20 sessions. Methods: participated in speech therapy 8 patients aged seven to nine years, school age, in a public school. For the analysis of the data set as a criterion for participation, the individual who completed at least 16 sessions of therapy, or one that reached the proposed objectives (adequacy of skills) in fewer sessions. For each session, which occurred weekly, lasting 40 minutes each, was conducted cursive record the child’s performance for each of the skills worked (location, discrimination, recognition, figure-ground/closing, comprehension e memory). Subsequently, we performed a descriptive content analysis of similarity between the skills. In the record was marked session considered the end of the activity, that is, the acquisition of skill. Results: the number of sessions held by the study subjects ranged from 10 to 20 sessions and the average length of sessions for each skill acquisition of auditory worked varied from three to 16 sessions. Conclusion: it was possible to observe adequacy in auditory skills in all subjects of the group, with a range of time worked for each skill. Studies with larger samples are essential to achieve time markers for the acquisition of auditory skills in this population segment.Modelo de estudo: estudo descritivo e transversal. Objetivo do estudo: caracterizar o tempo de aquisi- ção de cada habilidade auditiva trabalhada em crianças diagnosticadas com Distúrbio do Processamento Auditivo Central, em idade escolar, a partir de um programa de intervenção fonoaudiológica pré-estabelecido, com duração máxima de 20 sessões. Metodologia: foram selecionados, para a intervenção fonoaudiológica, 8 indivíduos na faixa etária de sete a nove anos, em idade escolar, de uma escola pública e que completasse, no mínimo, 16 sessões de terapia, ou, ainda, aquele que atingisse os objetivos propostos (adequação das habilidades) em menor número de sessões. Para cada sessão, que ocorreu semanalmente, com duração de 40 minutos, foi realizado registro cursivo do desempenho da crian- ça, para cada uma das habilidades trabalhadas (localização, discriminação, reconhecimento, figura-fundo/ fechamento, compreensão e memória). Posteriormente, foi realizada análise do conteúdo descritivo por semelhança entre as habilidades. No registro, foi assinalada a sessão considerada como término da atividade, isto é, a aquisição da habilidade. Resultados: o número de sessões realizadas pelos indivíduos do estudo variou de 10 a 20 sessões, sendo que o tempo médio de sessões para a aquisição de cada habilidade auditiva trabalhada oscilou entre três e 16 sessões. Conclusões: foi possível observar adequação das habilidades auditivas em todos os indivíduos do estudo, com variação de tempo para cada habilidade trabalhada. Estudos com maior casuística são fundamentais para que se alcancem marcadores de tempo para aquisição de habilidades auditivas, nesse segmento populacional