ABSTRACT The search for bioherbicides has been encouraged, and plants used in food or with bioactivity have been studied. Therefore, this article aimed to investigate the bioherbicidal potential of essential oils from Psidium cauliflorum and P. acidum through a plant toxicity bioassay using Lactuca sativa and Sorghum bicolor. The seeds were treated with essential oils of both species, along with control groups treated with distilled water, dichloromethane, and glyphosate. Germination percentage (GP), germination speed index (GSI), root growth (RG), shoot length (SL), mitotic index (MI), chromosomal alterations (CA), and nuclear alterations (NA) were evaluated. The major compound of the essential oil of P. cauliflorum was α-pinene, and of P. acidum were trans-caryophyllene, β-elemene, germacrene A, and α-copaene. The essential oils from both species exhibited phytotoxic effects. P. acidum oil inhibited sorghum RG and lettuce SL, while P. cauliflorum oil reduced GP, GSI, RG, and SL in both plants, indicating higher phytotoxicity than P. acidum and non-selective behavior. Cytotoxic investigations showed that both oils inhibited the MI. CA analysis revealed that P. cauliflorum oil exhibited aneugenic and clastogenic action mechanisms. The results demonstrate the bioherbicidal potential of P. cauliflorum essential oil, in addition to being non-selective and displaying a similar inhibition rate to glyphosate.

Resumo Investigar a diversidade genética em populações naturais de espécies com potencial para uso em programas de reflorestamento é um passo importante para a tomada de decisões relacionadas ao planejamento e manejo dos plantios. No entanto, programas de reflorestamento com espécies nativas no Brasil raramente são realizados com base no conhecimento do genótipo das matrizes doadoras das sementes utilizadas para produção de mudas. Este é o caso de Myrsine umbellata, um arbusto dioico pertencente à família Primulaceae, que vem sendo utilizado em programas de reflorestamento no Brasil principalmente por apresentar elevada capacidade de produção de frutos atrativos à avifauna. O objetivo deste estudo foi mensurar a diversidade genética intra e interpopulacional em populações naturais de M. umbellata em seis remanescentes florestais da Floresta Atlântica, utilizando marcadores ISSR. Os resultados revelaram que a diversidade genética intrapopulacional foi maior que a diversidade genética entre as populações estudadas. Por essa razão, o cultivo de mudas a partir de sementes obtidas em mais de uma população parece ser a estratégia mais apropriada para reflorestamento. Mesmo considerando que as populações mais isoladas são aquelas mais estruturadas, todas as populações de M. umbellata incluídas neste estudo revelaram ser importantes bancos de germoplasma conservados in situ.

Abstract The investigation of genetic diversity in natural populations of species that show potential for use in reforestation programs is a key step in making management decisions. However, reforestation programs with native species in Brazil are still rarely based on a genetic understanding of the seed matrices used for seedling production. This is also the case for Myrsine umbellata, a dioecious shrub within the family Primulaceae that has been used in reforestation programs in Brazil, mainly due to its high production capacity of fruits attractive to the avifauna. The goal of this study was to measure intra- and interpopulational genetic diversity in natural populations of M. umbellata in six forest remnants of the Atlantic Forest using ISSR markers. The results revealed that the intrapopulational genetic diversity was greater than the genetic diversity among the studied populations. For this reason, the cultivation of seedlings from seeds obtained in more than one population seems the most appropriate strategy for reforestation purposes. Even though the most isolated populations are also the ones with highest genetic structure, all populations of M. umbellata included in this study revealed to be an important germplasm bank conserved in situ.

Resumo Euterpe edulis, uma palmeira ameaçada de extinção da Mata Atlântica, tem importância ecológica e econômica pelo uso da polpa dos frutos. A identificação de matrizes geneticamente divergentes nas populações é útil para a conservação e o melhoramento da espécie. Neste trabalho, objetivou-se estimar a diversidade genética de plantas divergentes morfologicamente que possam ser utilizadas como matrizes, e de suas famílias de progênies em uma área manejada e em áreas de populações naturais da espécie no estado do Espírito Santo. Foram avaliadas 21 matrizes, das quais 13 obtidas em área manejada para a exploração sustentável dos frutos (anteriormente avaliadas quanto a caracteres de frutos) e oito oriundas de populações naturais no estado do Espírito Santo. Para cada matriz avaliou-se 10 progênies, constituindo 21 famílias. A partir de genotipagem por marcadores microssatélites, a caracterização das plantas matrizes e suas progênies foi realizada pelas heterozigosidades observada (Ho) e esperada (He) e o índice de endogamia (f), bem como a análise de variância molecular das plantas oriundas dos diferentes locais de coleta. As matrizes da área de cultivo manejada de Rio Novo do Sul apresentaram maiores Ho e He e menor f, indicando maior diversidade. Menores Ho (0,36) e He (0,41) e maior f (0,15) foram observados para as matrizes de Pinheiros, indicando menor diversidade e maior endogamia. A análise da variância entre os locais de coleta das matrizes revelou maior variação genética intrapopulacional que interpopulacional. As matrizes coletadas em populações naturais, Linhares e, especialmente, de Pinheiros, apresentam menor diversidade genética. Na área manejada, os indivíduos apresentaram maior diversidade para as matrizes e suas progênies, indicando potencial para a conservação e uso sustentável do recurso genético nesta área. As matrizes indicadas para cruzamento, com possibilidade de gerar descendentes com maior desempenho morfológico para frutos e alta diversidade foram RNS_154 e RNS_76.

Abstract Euterpe edulis, an endangered palm tree from the Atlantic Forest, has ecological and economic importance through the use of fruit pulp. Identifying genetically divergent matrices in populations is useful for species conservation and breeding. The present study aimed to estimate the genetic diversity of morphologically divergent plants that may be used as stock specimens as well as that of their progeny families, in a managed area and in areas of natural populations of the species in the state of Espírito Santo, Brazil. Twenty-one matrices were evaluated, of which 13 were obtained from areas managed for the sustainable exploitation of fruits (previously evaluated for fruit traits) and eight from natural populations in the state of Espírito Santo. For each matrix, 10 progenies were evaluated, constituting 21 families. From microsatellite marker genotyping, the characterization of the parent plants and their progenies was performed by the observed (Ho) and expected (He) heterozygosities and the inbreeding index (f), as well as the molecular variance analysis of the plants from the different plants. The matrices of the managed area of Rio Novo do Sul presented higher Ho and He, and lower f, indicating greater diversity. Lower Ho (0.36) and He(0.41) and higher f (0.15) were observed for Pinheiros matrices, indicating lower diversity and inbreeding. Analysis of variance between the collection sites of the matrices revealed greater intrapopulation than interpopulation genetic variation. The matrices collected from natural populations, Linhares and, especially, from Pinheiros, present less genetic diversity. In the managed area, the individuals presented greater diversity for the matrices and their progenies, indicating potential for the conservation and sustainable use of the genetic resource in this area. The matrices indicated for breeding, with the possibility of generating descendants with higher morphological performance for fruits and high diversity were RNS_154 and RNS_76.

Abstract Euterpe edulis is an endemic species of the Atlantic Forest that is threatened by the unsustainable exploitation of palm heart. Fruit management is an alternative to overcome this problem, promoting income generation, preserving the trees in forest remnants and motivating the implementation of farms for commercial production. In this study, the genetic diversity and structure of four natural populations of E. edulis were evaluated using microsatellite markers and six morphological fruit traits, analyzed with and without the REML/BLUP method. The longitudinal diameter had the strongest influence on the differentiation of genotypes. The genetic differentiation among populations was low and inbreeding was detected within populations among sites. Molecular and morphological data indicated high genetic diversity in the E. edulis populations. The REML/BLUP analysis increased the accuracy of morphology-based estimates of genetic diversity, thus contributing to improve breeding strategies for fruit quality and genetic conservation by use in E. edulis.

ABSTRACT. The palm tree juçara (Euterpe edulis Mart) is considered one of the most important and threatened native species in the Atlantic Forest. The search for juçara seeds (Euterpe edulis Martius) has increased, generating a need for technologies favorable to their production, quality and conservation. The aim of this study was to describe the seed germination patterns of 45 juçara accessions by using a nonlinear model to examine the behavior of these patterns and select superior genotypes. After clustering 45 juçara accessions into four groups, four nonlinear models, namely, the logistic, Gompertz, von Bertalanffy and Weibull models, were tested based on their fit for each group of accessions. The Gompertz model presented the best fit to describe the germination growth curve of E. edulis seeds. Groups 3 and 4 presented the highest daily germination rates and were considered the most vigorous. Analysis of deviance was performed, revealing genetic variability among the genotypes in terms of seed germination and vigor. It was possible to find a nonlinear model that best explained our data, and this model may also be a promising model for other palm tree species. It is possible to select genotypes based on the characters we analyzed, due to the elevated genetic variability.

Resumo Euterpe edulis (palmiteiro-juçara) é uma arbórea de porte alto que ocorre naturalmente em florestas da Mata Atlântica e Cerrado. Por estas características é difícil coletar folhas jovens, sadias e frescas para obtenção de DNA genômico de boa qualidade para a espécie, necessárias para estudos de biologia molecular. Visando facilitar coletas a campo de material biológico, neste estudo foi proposto o isolamento de DNA a partir de tecidos vegetais do córtex. Foi comparado o DNA genômico obtido a partir de dois tipos de tecido vegetal, sendo estes, folhas jovens oriundas de mudas e do córtex de plantas adultas. A integridade do DNA obtido foi confirmada por eletroforese, revelando DNA genômico com pouca degradação e a qualidade da purificação foi verificada pelos critérios de razões de absorbâncias de 260/280 nm e 260/230 nm, apresentando padrão similar nos dois tipos de tecidos avaliados. As concentrações de DNA em folha variaram de 81,9 a 310,1 ng/μL, e no córtex, de 105,2 a 404,8 ng/μL. A confirmação da qualidade do DNA obtido foi determinada por amplificação de microssatélites nos quais os produtos apresentaram bandas definidas para os dois materiais vegetais. Assim, o DNA genômico isolado a partir do córtex de Euterpe edulis constitui um tecido vegetal adicional para obtenção de DNA genômico de igual qualidade, quantidade e integridade que o obtido de folhas, com a vantagem da coleta ser facilitada a campo.

Abstract Euterpe edulis is an arboreal species of high size that occurs naturally in the Atlantic Forest and in ‘Cerrado’ forests. For these characteristics, it is difficult to collect young, healthy and fresh leaves to obtain the genomic DNA of sufficient quality for the species, required for molecular biology studies. To facilitate the collection of biological material field, this study proposed the isolation from plant tissue in the cortex. Isolation and analyzes were carried out compared with the DNA obtained from young leaves coming from plants and tissue of the cortex of adult plants. The integrity of the DNA obtained was confirmed by electrophoresis, revealing the genomic DNA degradation and the low quality of the purification was checked by absorbance ratios criteria 260/280 nm and 260/230 nm, with a similar pattern in both types of tissues evaluated. DNA concentrations ranged from 81.9 to 310.1 ng/µl and cortex, from 105.2 to 404.8 ng/µl. The confirmation of the quality of the DNA obtained was determined by microsatellite amplification, where the products showed bands defined for both plant materials. Thus, the genomic DNA isolated from the cortex of Euterpe edulis, constitutes an additional plant tissue to obtain a genomic DNA of equal quality, quantity and integrity of the obtained sheets with the advantage of the collecting being facilitated in the field.

ABSTRACT DNA fingerprinting based on SSR amplification profiles was applied to native species of Piper from the Atlantic Forest to compare the utility of this type of molecular marker with the morphological characters traditionally applied in Piper taxonomy and identification. Fifty-one SSR markers developed for four species of Piper native to Asia and Mesoamerica were applied to 16 species, together with 63 morphological characters, for species characterization. Molecular and morphological data were analysed by cluster analysis, followed by a cluster sharpness test and the construction of a heat map to visualize the association of characters with species groups. A multivariate regression tree determined the number of loci needed for species identification. Forty-five primers were transferable to at least four species. Molecular data were more efficient in detecting sharp groups than morphological data. Species groups delimited by a set of shared morphological characters were differentiated based on molecular data. The sixteen studied species could be separated by nine primers, demonstrating the cross-species transferability of SSR markers and the usefulness of DNA fingerprinting for both the delimitation and the identification of species of Piper.

ABSTRACT Although a species’ sexual system may influence the genetic diversity of its populations in their natural environment, there have been few such studies involving indigenous species of the Atlantic Forest. Here we study Myrsine coriacea, a dioecious tree widely used in reforestation programs despite a lack of information about its natural interpopulation genetic variation. To address this knowledge gap, intra- and interpopulation genetic diversity were measured for male and female individuals of ten natural populations using ISSR markers. Greater intrapopulation genetic diversity indicated interpopulation gene flow, regardless of isolation and distance between populations. Multivariate analyses detected significant differences in genetic diversity between populations, but not between males and females, which indicates that genetic diversity did not differ between the two sex morphs. Distance between populations was unrelated to genetic diversity. Myrsine coriacea has not experienced a loss of genetic variability despite the characteristic segregated spatial distribution of its populations. These results suggest that obligatory cross-pollination and dispersal by birds may be important mechanisms for the maintenance of genetic diversity in natural populations of M. coriacea.

Abstract The objective of this work was to map QTL for agronomic traits in a Brazilian soybean population. For this, 207 F2:3 progenies from the cross CS3035PTA276-1-5-2 x UFVS2012 were genotyped and cultivated in Viçosa-MG, using randomized block design with three replications. QTL detection was carried out by linear regression and composite interval mapping. Thirty molecular markers linked to QTL were detected by linear regression for the total of nine agronomic traits. QTL for SWP (seed weight per plant), W100S (weight of 100 seeds), NPP (number of pods per plant), and NSP (number of seeds per plant) were detected by composite interval mapping. Four QTL with additive effect are promising for marker-assisted selection (MAS). Particularly, the markers Satt155 and Satt300 could be useful in simultaneous selection for greater SWP, NPP, and NSP.

RESUMO A palmeira Euterpe edulis é uma espécie nativa da Mata Atlântica e atualmente se encontra na lista das espécies ameaçadas de extinção. Uma alternativa para retirá-la desta lista seria o estímulo para o plantio comercial, focando o manejo dos frutos, que recebem a classificação de “superfruta” pelas suas propriedades químicas e nutricionais. Entretanto, uma etapa de extrema importância que precede a seleção de genótipos superiores é o estudo das associações entre as variáveis, pois permite traçar estratégias de seleção alternativas para maximizar os ganhos. O presente trabalho teve por objetivos estimar as correlações genéticas pelo procedimento REML/BLUP e os efeitos diretos e indiretos sobre a massa dos frutos, por meio da análise de trilha, para seis caracteres de frutos de 198 acessos de E. edulis. Foram analisados frutos de 198 genótipos de juçara coletados em 20 fragmentos florestais na região Sul e Caparaó do Estado do Espírito Santo. De cada genótipo, avaliaram-se 25 frutos para as características: diâmetro longitudinal e equatorial do fruto e da semente; e massa do fruto e da semente. Os dados obtidos foram utilizados para a estimativa das correlações genéticas através do método de máxima verossimilhança restrita e melhor predição linear não viesada (REML/BLUP). Posteriormente, as correlações genéticas entre as variáveis de fruto foram submetidas à análise de trilha. Os seis caracteres de fruto estudados apresentam associação genética positiva com magnitude superior a 0,71 pelo procedimento REML/BLUP. O diâmetro longitudinal do fruto e a massa das sementes possuem maior efeito direto sobre a massa dos frutos, o que as torna mais indicadas para aumentar as chances de sucesso na seleção de genótipos de juçara com frutos maiores. As características diâmetro longitudinal do fruto e a massa das sementes são as principais determinantes das variações na massa dos frutos.

ABSTRACT The palm tree Euterpe edulis is a native species from Mata Atlântica and it is nowadays found in the list of species which are threatened by extinction. One option to withdraw it from this list would be the stimulation of the commercial planting aiming the management of fruits which receive the “super fruit” classification by their chemical and nutritional properties. However, one stage of extreme importance that precedes the superior genotypes selection is the study of associations among the variables, because it allows delineating alternate selection strategies to maximize the gains. The present study had as objective to estimate the genetic correlations by the REML/BLUP procedure and the direct and indirect effects upon fruit mass by path analysis for six fruit characters of 198 accessions of E. edulis. Fruits of 198 Juçara genotypes collected in 20 forestry fragments in the south and Caparaó region of the state of Espírito Santo were analyzed. From each genotype 25 fruits were evaluated for the characteristics: longitudinal and equatorial fruit and seed diameter; fruit and seed mass. The obtained data were used for genetic correlations estimative through the method of restricted maximum likelihood and better unbiased linear prediction (REM/BLUP). Subsequently, the genetic correlations among the fruit variables were submitted to path analysis. The six fruit characters studied show positive genetic association with magnitude higher than 0.71 by the REML/BLUP procedure. The longitudinal diameter of fruit and seed mass have greater direct effect on fruit weight, which makes them most indicated to increase the chances of success in the Juçara genotypes selection with larger fruit . The characteristics longitudinal diameter of fruit and the seed mass are the main determinants of changes in the mass of fruit.

A seleção assistida por marcadores (SAM) permite identificarlinhagens resistentes com base em alelos de marcadores genéticos ligados aocaráter, o que reduz o número de linhagens avaliados fenotipicamente, uma daslimitações ao desenvolvimento de cultivares resistentes ao nematoide de cistoda soja (NCS). Neste trabalho objetivou-se avaliar a eficiência demicrossatélites próximos a QTLs de resistência ao NCS, nos grupos de ligação (GL) G e A2 da soja, na seleção de genótipos resistentes em populaçõesoriginadas do cruzamento entre as cultivares Vmax e CD201. O QTL do GL A2 nãofoi detectado em 'Vmax' (derivada da PI 88788). A SAM por microssatélites do GLG foi eficiente na seleção de famílias F6:7 resistentes emoderadamente resistentes à raça 3 do NCS. Os microssatélites Sat_168, Satt309e Sat_141 apresentaram eficiência de seleção maior que 93%.

Resistant lines can be identified by marker-assisted selection(MAS), based on alleles of genetic markers linked to the resistance trait. This reduces the number of phenotypically evaluated lines, one of the limitations in the development of cultivars with resistance to soybean cyst nematode (SCN).This study evaluated the efficiency of microsatellites near quantitative traitloci (QTL) for SCN resistance, in the linkage groups (LG) G and A2 of soybean, for the selection of resistant genotypes in populations originated from crosses between the cultivars Vmax and CD201. The QTL of LG A2 was not detected in 'Vmax' (derived from PI 88788). In MAS, the microsatellites of LG G were efficient in selecting F6:7 families with resistance and moderate resistance to SCN race 3. The selection efficiency of the microsatellites Sat_168, Satt309 and Sat_141 was greater than 93%.

O Brasil é um dos maiores produtores de goiaba, Psidium guajava L., do mundo. Pomares de propagação seminal, devido à polinização cruzada, apresentam ampla variabilidade, permitindo a seleção de genótipos ao melhoramento. O objetivo deste trabalho foi estudar a diversidade genética de genótipos de goiabeiras selecionadas em pomar de origem seminal (denominadas Cortibel de I a XIII) e compará-las às cultivares Paluma e Pedro Sato, e ao genótipo Roxa, quanto a características morfológicas e de qualidade de frutos. Verificou-se divergência entre os genótipos Cortibel. A Cortibel I, de polpa vermelha, foi o genótipo mais divergente, exibindo o melhor desempenho para as características de frutos. Os genótipos CVIII e CIV apresentaram os melhores desempenhos dentre os genótipos de polpa clara. As seleções de Cortibel apresentaram desempenho semelhante a cultivares comerciais para a qualidade do fruto, sendo bons materiais para o uso como novas cultivares ou para hibridações em programas de melhoramento.

Brazil is one of the largest producers of guava, Psidium guajava L., of the world. Orchards from seminal propagation, owing to cross-pollination, result in large variability, allowing the selection of genotypes for crop improvement. The aim of this essay was to study the genetic diversity of genotypes selected from seminal origin orchard (named Cortibel I to XIII) and compare them to Paluma and Pedro Sato and Roxa genotype (purchased in nursery), by morphological and quality of fruit characteristics. There was divergence between Cortibel selections. Cortibel I was the most divergent between red pulp genotypes and between all the others, showing the best performance for fruit characteristics. CVIII and CIV genotypes obtained the best performance between light pulp genotypes. Cortibel selections presented similar performance about fruit quality to commercial crops, providing good material for use as new cultivars or for hybridizations in breeding programs.

O objetivo deste trabalho foi identificar locos associados a características quantitativas (QTL) de efeito maior e menor para a resistência às raças 3, 9 e 14 do nematoide do cisto da soja (NCS) na cultivar Hartwig, mapear novos QTLs de resistência para estas raças e verificar a existência de interações epistáticas entre QTLs. A cultivar Hartwig é uma importante fonte de resistência ao NCS. Linhagens endogâmicas recombinantes (LER) obtidas do cruzamento entre 'Hartwig' (resistente) e Y23 (suscetível) foram avaliadas quanto à resistência às três raças. Novas regiões genômicas de resistência ao NCS foram identificadas por microssatélites. Quatro QTLs, que explicaram entre 12 e 34% da variância fenotípica, foram detectados para a resistência à raça 3 nos grupos de ligação (GL) A2, G, J e M. O QTL no GL G também é importante para a resistência à raça 9. Interações epistáticas foram detectadas entre loci, o que indica resistência às raças 9 e 14. Há QTLs de maior e menor efeito para a resistência ao NCS.

The objective of this work was to identify major and minor-effect quantitative trait loci (QTL) for resistance to races 3, 9, and 14 of soybean cyst nematode (SCN) in Hartwig cultivar; to map new resistance QTLs for these races; and to check for the existence of epistatic interactions between QTLs. Cultivar Hartwig is an important resistance source to SCN. Recombinant inbred lines (RIL) obtained from a cross between 'Hartwig' (resistant) and Y23 (susceptible) were evaluated regarding resistance to the three races. New genomic regions for resistance to SCN were identified by microsatellites. Four QTLs, which explained between 12 and 34% of phenotypic variance, were detected for resistance to race 3 in linkage groups (LG) A2, G, J, and M. The QTL in LG G is also important for resistance to race 9. Epistatic interactions were detected between loci, which indicate resistance to races 9 and 14. There are high and low-effect resistance QTLs to SCN.

O objetivo deste trabalho foi detectar e mapear locos de caracteres quantitativos (QTL) que afetam os conteúdos de proteína e óleo em soja (Glycine max L. Merr.). Plantas F2, derivadas do cruzamento entre a linhagem CS3032PTA276 e a variedade UFVS2012, foram cultivadas em casa de vegetação e forneceram as folhas para extração e análise de DNA. Quarenta e oito marcadores microssatélites (SSR) polimórficos foram avaliados na população F2. A avaliação dos fenótipos foi realizada em 207 famílias das progênies F2:3, em um delineamento em blocos ao acaso, com três repetições, conduzido em Viçosa, MG, em 2006. Foram detectados quatro QTL associados ao conteúdo de proteína, nos grupos de ligação D1a, G, A1, e I, e três QTL associados ao conteúdo de óleo, nos grupos A1, I e O. A variação fenotípica explicada pelos QTL variou de 6,24 a 18,94% e 17,26 a 25,93%, respectivamente, para os conteúdos de proteína e óleo. Foram detectados novos QTL associados aos conteúdos de proteína e óleo, além dos previamente relatados em outros estudos. Regiões distintas das atualmente conhecidas podem estar envolvidas no controle genético do teor de proteína e óleo na soja.

The objective of this study was to detect and map quantitative trait loci (QTL) affecting soybean (Glycine max L. Merr.) protein and oil contents. F2 plants, derived from the cross between the CS3032PTA276 line and the variety UFVS2012, were grown in a greenhouse and provided the leaves for DNA extraction and analysis. Forty-eight polymorphic microsatelite markers (SSR) were evaluated in the F2 population. Evaluation of the phenotype was performed in 207 families from F2:3 progenies, in a complete block design with three replicates, carried out in Viçosa, MG, Brazil, in 2006. Four QTL associated with protein content, in linkage groups D1a, G, A1, and I, and three QTL for oil content in groups A1, I and O were identified. Phenotypic variation for protein and oil explained by QTL ranged from 6.24 to 18.94% and 17.26 to 25.93%, respectively. New QTL associated with protein and oil contents were detected, besides those previously reported in other studies. Other regions may be involved in the genetic control of protein and oil contents in soybean besides those already known.