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Native to the tropical Americas, guava (Psidium guajava L.) is an important crop in Brazil. However, the emergence of so-called guava decline, a complex disease resulting from root parasitism by the root-knot nematode (Meloidogyne enterolobii Yang & Eisenback) in association with opportunistic fungi, has decimated guava orchards across Brazil and in other countries. In the present study, seminiferous guava accessions were vegetatively propagated by minigrafting and their genotypes preserved for resistance reassessment in clones to confirm or not host plant reactions. The results indicated a highly virulent parasite, high host suitability of the P. guajava species, and widely varying reactions among plants of the same genotype and between different genotypes, demonstrating that the strategy of preserving the germplasm and reassessing reactions in clones may be important in identifying and selecting germplasms with a degree of resistance to M. enterolobii. The progeny of cv. Paluma P02R5R2 obtained the lowest average parasite reproduction factor (RF = 22.11) among the genotypes evaluated and was; therefore; classified as moderately resistant and preserved for future research. [ABSTRACT FROM AUTHOR]

RESUMO A Caesalpinia ferrea var. leyostachia (pau-ferro) e Cassia grandis (canafístula) apresentam importância para obtenção de mudas para recuperação de áreas degradadas, porém pouco se tem na literatura sobre estas espécies. Objetivando-se identificar diferenças em perfis enzimáticos destes indivíduos foi realizado o presente trabalho. Realizou-se extração de enzimas Álcool Desidrogenase, Esterase, Glutamato Oxaloacetato Transaminase, Peroxidase e Glucose Desidrogenase. Em apenas três dos sistemas observou-se atividade, sendo a Esterase a que apresentou maior número de bandas. Notaram-se perfis diferenciados entre os genótipos de canafístula e entre os genótipos de pau-ferro avaliados, permitindo-se inferir sobre a diversidade existente entre os indivíduos.

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cassava is cultivated by family farmers who preserve local landraces in their proprieties, acting as guardians of this genetic resource. The existing genetic diversity for the species can be estimated using microsatellite molecular markers. Thus, the objective was then to carry out the molecular characterization of four local varieties of cassava (Cacau Branca, Cacau Roxa, Cacau Amarela and Mandioca Pão) cultivated by family farmers in the municipality of Apiacás, Mato Grosso state, Brazil using microsatellite markers. Four local landraces of cassava were sampled, totaling 40 individuals. Leaf material was used for DNA extraction and PCR amplification. A total of 67 alleles were amplified, with SSRY126 and SSRY21 amplifying the highest and lowest number of alleles, respectively. Among the amplified alleles, 33 rare alleles (49%) were identified. The observed heterozygosity (0.840) was higher than the expected heterozygosity (0.643), reflecting negative fixation indices. Loci with PIC values above 0.5 were GA12, GA131, GA140, SSRY27, SSRY28, and SSRY126. The dendrogram formed by the UPGMA hierarchical clustering generated five genetic clusters, which were in agreement with the Bayesian analysis. Thus, genetic diversity was observed among the local landraces cultivated in the family farmers' fields in the municipality of Apiacás. The AP5 and AP20 individuals are the most genetically divergent among the analyzed group, and the Mandioca pão landrace is the most genetically distant from the other three landraces. [ABSTRACT FROM AUTHOR]

The physicochemical characterization, antioxidant potential and phenolic composition of fruits of six genotypes (BB3, BB4, BB6, PW1, PW2 and PW5) and seven commercial cultivars (Bluebelle, Bluegem, Briteblue, Climax, Delite, Powderblue and Woodard) were carried out of blueberry, from the 2019/2020 production cycle. Color, soluble solids content, pH, titratable acidity, antioxidant activity (DPPH and ABTS), total phenolic compounds, total flavonoids, total anthocyanins and individual anthocyanins were analyzed. In general, all genotypes and cultivars are rich in phytochemicals. The genotypes PW1, PW2, PW5, BB3 and the cultivars Bluegem, Briteblue, Climax and Delite stand out. Thus, the blueberry genotypes in this study are considered as promising for the food industry and also for fresh consumption as commercial cultivars already consolidated in the fruit market, in view of the excellent phenolic composition present in these small fruits. [ABSTRACT FROM AUTHOR]

Estudos sobre a divergência genética da população base, bem como a caracterização dos genótipos são essenciais na seleção de genitores dentro de um programa de melhoramento genético. Portanto, esta pesquisa objetivou a caracterização morfológica de 33 genótipos de batata doce, a estimativa da divergência genética e a indicação de genitores para cruzamento biparentais. Foram avaliadas 14 características da parte aérea e 11 das raízes por meio de descritores morfológicos. A divergência genética foi estimada pelo teste de agrupamento Tocher, utilizando-se o algoritmo de Gower para o cálculo das medidas de dissimilaridade. Observou-se ampla variabilidade morfológica entre os genótipos, tanto na parte aérea, quanto nas raízes (comprimento, diâmetro, formato, pigmentação, coloração). A cor da epiderme da raiz variou do creme, rosado ao roxo avermelhado; já a cor da polpa variou de creme ao roxo escuro. Os descritores morfológicos da parte aérea e das raízes evidenciaram a existência de divergência genética, com a formação de seis grupos de similaridade entre os genótipos avaliados, possibilitando a indicação dos cruzamentos biparentais ‘CL 28 x Beterraba 1’, ‘CL 28 x Pão’, ‘CL 15 x Beterraba 1’, ‘CL 15 x Pão’, ‘CL 28 x F-16’, ‘CL 15 x F-16’, ‘CL 28 x F-15’, ‘CL 15 x F-15’, ‘F-15 x Beterraba 1’, ‘F-16 x Beterraba 1’, ‘F-15 x Pão’, ‘F-16 x Pão’, possibilitando ganhos com maior heterose e progênies superiores.

Resumo O presente estudo avaliou a variabilidade genética e estimou parâmetros genéticos em matrizes de Hevea brasiliensis com base no caráter germinação. Sementes de trinta matrizes da espécie foram coletadas e estabelecidas na Estação Experimental de Votuporanga, SP. O teste de germinação das sementes foi avaliado no viveiro da COMFLORA em Ponta Porã, MS. O ensaio foi estabelecido sob o delineamento de blocos ao acaso, com quatro repetições e dez sementes por parcela. Os dados obtidos foram analisados através do software Selegen - Reml/Blup. A estimativa de coeficiente de herdabilidade média de matrizes foi alta (0,99), sugerindo expressivo controle genético. A seleção das matrizes proporcionou ganho genético médio de 16,22%.

RESUMO O presente trabalho teve como objetivo verificar a existência de variabilidade genética entre três populações de Solanum lycocarpum estabelecidas em dois ecossistemas brasileiros: Cerrado e da Mata Atlântica. Avaliaram-se a porcentagem de germinação e seis caracteres morfológicos aos 20 dias após a emergência das plântulas. A análise de variância revelou a existência de variabilidade genética entre as populações para a porcentagem de germinação, comprimento médio do cotilédone e número médio de folhas.

Germplasm collections are key to assess genetic variability of forage germplasm. The objective of the present work was to study the amplified fragment length polymorphism (AFLP) presented by five Desmanthus spp. accessions. The study assessed the AFLP polymorphism of Desmanthus pernambucanus (L.) Thellung in Pernambuco, Brazil, and D. pubescens B.L. Turner AusTRC from Saint Croix, U.S. Virgin Islands. The 38 primers pairs tested resulted in 32 combinations and amplified 707 amplicons, of which 436 (62%) were polymorphic and 271 (38%) monomorphic, indicating a wide variability among the five Desmanthus accessions. Nei's genetic distance matrix pointed that 89F and AusTRC, distinct species collected from different locations (Bom Jardim and Saint Croix, USA), presented lesser genetic distance (33.5%) than 43F and 100C, belonging to D. pernambucanus but collected in Bom Jardim and Sertânia, respectively, with 57.1% distance. D. pernambucanus accessions 43F and 89F were the closest geographically located, however, presented expressive genetic distance (63.0%). The genetic variability of native germplasm could become important in increasing genetic adaptation and environmentally viable forage species. [ABSTRACT FROM AUTHOR]

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rice production (Oryza sativa L.) is among the most economically important activities in the world. However, soil and salinity coming from irrigation water reduce rice yield. Therefore, the identification and/or development of salt-tolerant rice genotypes is a strategy to minimize this problem. The development of new genotypes depends on the presence of genetic diversity, and understanding the heritability of a desired trait can help in the selection process. Thus, this study aimed to identify superior genotypes, analyze the genetic diversity and estimate the heritability for salinity tolerance at the seedling stage in rice genotypes used in Brazil. For this, seedlings of 69 genotypes were kept in hydroponic solution with 40 mM NaCl (4 dSm-1) for seven days. Shoot length, root length, shoot dry weight, and root dry weight) were evaluated and the results were converted into relative performance. Tolerant and moderately salt-tolerant genotypes were identified at the seedling stage, which can be used in breeding programs and can be cultivated in high salinity areas. Principal component analysis showed the presence of genetic diversity for salinity response. Finally, it was shown that most of the observed variation is of genetic origin, which can make the breeding process less difficult. [ABSTRACT FROM AUTHOR]

The genetic variability in plant populations can be estimated through multivariate analysis, which allows to analyze the genotypes based on a set of traits to identify the traits with the greatest influence for the divergence and the correlation between them. In this sense, the objective of the present work was to estimate the genetic divergence between golden flax lines using multivariate analysis for initial plant selections. For this purpose, 73 lines, in addition to the control, were tested in a randomized complete block design, with three replications, and traits of cycle, stature, and yield were measured. Twelve groups were obtained based on the Mahalanobis distance estimate and Tocher cluster, and the technical length was the most important trait for the dissimilarity. The line of group XI was promising, with early maturation and satisfactory seed productivity. The graphic of dispersion of the canonical variables showed the most divergent lines, and the greatest divergence was observed between groups III and IV. Multivariate analysis was an important tool for the initial choice of superior golden flax. [ABSTRACT FROM AUTHOR]

The development of disease resistant coffee cultivars is of paramount importance to increase grain yield and decrease production costs. The lack of information on how the new cultivars resist the attack of diseases and pests is a limiting factor in the selection of the best cultivars. Thus, the objective of the present work was to select superior genotypes of the Big Coffee VL group for resistance to Hemileia vastatrix and Cercospora coffeicola. The experiment consisted of 18 progenies pre-selected from a group of 100 genetic materials, for the trait of productivity. The experiment was carried out in a randomized block design, with six blocks and one plant per experimental plot, totaling 108 individuals. The selected coffee plants were evaluated for 10 months for injuries caused by coffee leaf rust and brown eye spot using commonly used diagrammatic scales. During the evaluated months, the genotypes G10, P32 and M22 were more tolerant to rust and brown eye spot. Thus, they are good candidates for genetic improvement programs with the objective of producing larger grains and adding resistance to the main diseases of arabica coffee. [ABSTRACT FROM AUTHOR]

The agronomic characteristics and chemical composition of soybean grains depend on seeding times and the availability of nutrients and may cause different grouping in studies on genetic diversity. Two assays (29/11/2015 and 14/01/2016) in randomized blocks with 60 treatments and three replications were conducted in Palmas TO Brazil, to determine the effects of seeding periods and potassium doses on genetic diversity in soybean cultivars. Treatments were designed in a factorial scheme 10x6, namely, ten soybean cultivars (BRS 325 RR; M 9144 RR; BRS 33871 RR (SAMBAIBA); TMG 1288 RR; BRS 333 RR; P 98Y70; TMG 1180; BRS 9090 RR; M 8766; and BRS 8990 RR) and six doses of potassium fertilizers (0, 40, 80, 120, 160, 200 kg ha-1). The agronomic and chemical characteristics of the grains were analyzed. Analysis of variance was undertaken for each assay and for each dose. Tocher's grouping method and Singh's criterion were applied to quantify relative contribution for genetic divergency. Potassium doses and seeding times provided different cultivar groupings. Dose 120 kg ha-1, recommended by soil analysis, provided the greatest genetic differences among cultivars and may be employed in further works on improvement in studies on genetic divergences. As a rule, grain productivity greatly contributed towards genetic divergency. [ABSTRACT FROM AUTHOR]

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Brazilian savanna, regionally known as Cerrado, is characterized by a great diversity of physiognomies and holds the highest species diversity and level of endemism among world savannas. However, due mainly to agribusiness, this vegetation is among the most threatened ones, currently presenting alarming rates of extinction. Among the species present in the "red list" we find the endemic Gymnopogon doellii, a grass whose distribution is restricted to a few sites. In the Federal District and surroundings, for example, only one population, with scattered subpopulations, is known, within the limits of the Brasilia National Park. By this study we raised information related to the biology of G. doellii, as population size and distribution, genetic variability and germination characteristics. Besides, we produced seedlings in greenhouse, planted in different physiognomies of the Cerrado and followed them for almost four years to check for their survival, growth and fruiting under natural conditions. Seedlings transplanted to the field presented high rates of recruitment (> 25%), growth patterns similar to wild plants and produced viable caryopses. We recommend transplanting of individuals of G. doellii for both in situ conservation as well as for the revegetation of degraded areas of the Cerrado. [ABSTRACT FROM AUTHOR]

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

O Centro de Incubação de Empreendimentos Populares Solidários (Cieps) vem desenvolvendo ações voltadas para a agricultura familiar dentro de uma perspectiva agroecológica. Torna-se importante o debate e a disseminação de saberes a respeito das Sementes Crioulas, as quais podem ser utilizadas para proporcionar maior autonomia aos agricultores familiares e assentados da reforma agrária, frente ao contexto de agricultura tecnificada e empresarial que os circunda. Assim, esse relato apresentou a experiência de uma Roda de Conversa que teve como objetivo principal a socialização de saberes e troca de experiências sobre Sementes Crioulas. A Roda de Conversa ocorreu durante a V Jornada Universitária em Defesa da Reforma Agrária em 2019, na Universidade Federal de Uberlândia. Foram apresentados alguns pontos para discussão e relatos dos participantes subdivididos nos seguintes temas: independência produtiva; preservação genética; e iniciando um banco de sementes. Trazer o tema para ser discutido com agricultores familiares e assentados da reforma agrária, em tempos de dominância consolidada dos pacotes tecnológicos recomendados pelo mercado convencional e muitas vezes inacessível ao produtor, contribui para que esses produtores viabilizem suas atividades agrícolas e possibilitem o desenvolvimento econômico social de forma independente.

The genus Capsicum displays a wide genetic variability and studies focusing on diversity among genotypes are used in breeding programs. This study aimed to estimate the genetic variability based on morphoagronomic descriptors of pepper genotypes. The experiment was installed in a completely randomized design with 12 treatments and five replicates. The genotypes were evaluated for nine morphological and horticultural traits. The analysis of genetic divergence among the genotypes was determined by multivariate techniques, based on principal components and cluster analysis, via hierarchical grouping with average linkage (Unweighted Pair-Group Method using Arithmetic Mean - UPGMA). All quantitative descriptors were significant at 1 and 5% by the F-test. Principal component analysis showed that the first two major components accumulated 70% of the total variance. The UPGMA grouping method delineated five distinct groups, indicating the existence of genetic variability among the studied genotypes. The genotypes that gathered attributes of relevant ornamental value were 'Pirâmide ornamental', 'Tabasco' and 'Malagueta'. The most promising genotypes for fresh consumption were 'Dedo de moça', 'Rocoto vermelha', 'Rocoto amarela' and 'Jalapeño'. These genotypes present the potential to be used in breeding programs of pepper plants for ornamental purposes. [ABSTRACT FROM AUTHOR]

O manejo das principais pragas de grãos armazenados tem sido feito, preferencialmente, com o uso de inseticida o que representa um enorme risco no desenvolvimento de resistência. Há muitos estudos com o Sitophilus zeamais visando seu controle, porém poucos analisando a variabilidade genética desta espécie. Este trabalho teve como objetivo estimar a variabilidade genética de S. zeamais em 10 amostras de diferentes localidades, destas, oito são do Brasil: Tunápolis (SC), Iguatemi (PR), Piracicaba (SP), Coimbra (MG), Maracaju (MS), Canarana (MT), Jataí (GO), Picos (PI) e duas são do Paraguai: Amambay e Pedro Juan Caballero. Para tal, foi utilizada a técnica de eletroforese de isozimas, em gel de amido para analisar seis sistemas enzimáticos (AAT, ACP, GPI, IDH, MDH e ME) e em gel de poliacrilamida que permitiu analisar uma enzima (EST). Concluiu-se que a espécie apresenta alta variabilidade genética (He), diferenciação moderada entre as amostras e as amostras foram agrupadas em três grupos.

The genetic diversity of Theobroma speciosum is important because its use in breeding programs, once the species is closely related to species of great economic value such as Theobroma cacao (cocoa) and Theobroma grandiflorum (cupuaçu). Thus, the objective of this work is to characterize the intra and interpopulational genetic diversity of Theobroma speciosum in natural populations in the Brazilian Amazon. Ninety individuals of T. speciosum from four populations localized in different states of legal Amazon were selected and genotyped. The data were obtained by fluorescence microsatellite analysis and the number of alleles, number of private alleles, fixation index, observed and expected heterozygosity were analyzed. Bayesian analysis, AMOVA and PCOa were used to reveal the molecular genetic structure of the populations, using the programs Structure and GenAIEx 6.5, respectively. All populations studied present great levels of gene diversity, although, there was a greater similarity among the AUR, API and MAC populations, while RBC population presented higher heterozygosity and less inbreeding than the others, becoming a possible refuge area in the Amazon, and the most important population for T. speciosum conservation. [ABSTRACT FROM AUTHOR]

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

O mercado brasileiro de arroz prioriza o consumo de arroz branco polido. Entretanto, existem demandas por tipos especiais. A estimativa da divergência genética é importante para o melhoramento genético, pois permite a seleção de genitores em sistemas de cruzamentos controlados. Assim, os objetivos deste trabalho foram indicar a contribuição relativa dos caracteres avaliados para a dissimilaridade genética e avaliar a divergência genética entre genótipos de tipos especiais de arroz por dois métodos diferentes de agrupamento. O experimento foi conduzido no ano de outubro de 2012 a março de 2013, na UFRRJ, Seropédica, RJ. O delineamento utilizado foi em blocos ao acaso, com cinco repetições. Os tratamentos constaram dos genótipos Caiapó, Vermelho Pequeno, IAC 300, IAC 400 e IAC 500. A medida de dissimilaridade adotada foi a distância euclidiana. Foram utilizados dois métodos diferentes de otimização: o método de otimização de Tocher e o método hierárquico UPGMA (Unweighted Pair-Group Method using Arithmetic Avarages). Os genótipos Caiapó e Vermelho Pequeno estiveram em diferentes grupos heteróticos em relação aos genótipos IAC 300 e IAC 400, independentemente do método de agrupamento utilizado. Verificou-se que a característica produtividade foi a que mais influenciou na variação total.

O objetvo deste trabalho foi estimar a divergência genétca entre 40 híbridos de milho de ciclo precoce. O experimento foi conduzido em área experimental no município de Chapecó, SC, no ano agrícola 2007/08. O delineamento experimental utlizado foi de blocos casualizados, com quatro repetições. As análises de variância univariada e multivariada revelaram diferenças entre os híbridos. Houve a formação de onze grupos dissimilares, sendo considerados promissores na formação de novas populações os híbridos DKB 240, CD 397, DOW 2B688, P30F36, XGN 7326, ASR 152, AS 1540, AS 1579, P30R50 e AS 1570 em virtude da maior dissimilaridade apresentada e da alta produtvidade de grãos.

A banana (Musa spp.) está entre as frutas mais consumidas do mundo. Embora exista um número expressivo de cultivares de bananeira, poucos apresentam importância comercial. Para avanços nos programas de melhoramento genétco dessa cultura, existe a necessidade de compreender a estrutura genômica e as relações genétcas existentes entre os acessos depositados nos bancos de germoplasma. Assim, o objetvo deste trabalho foi levantar a variabilidade genétca existente entre 15 acessos do Banco de Germoplasma de Bananeira da Epagri por meio da técnica RAPD. Foram utilizados 78 iniciadores de PCR, os quais geraram um total de 855 bandas polimórfcas. Os dados de presença/ausência de bandas foram submetidos à análise de conglomerados. Os resultados mostraram que os marcadores RAPD foram eficazes em revelar a existência de diversidade genétca entre os cultivares analisados, bem como em separar os grupos genômicos A e B e os cultivares de acordo com seus respectivos subgrupos.

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Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The brazilian rice market prioritizes the consumption of polished white rice. However, there are demands for special types. The estimation of genetic divergence is important for genetic improvement, as it allows the selection of parents in controlled crossbreeding systems. Thus, the objectives of this work were to indicate the relative contribution of the evaluated traits to the genetic dissimilarity and to evaluate the genetic divergence among genotypes of special types of rice by two different methods of grouping. The experiment was carried out from October 2012 to March 2013, at the UFRRJ, Seropédica, RJ. The design used was in randomized blocks, with five replications. The treatments consisted of the genotypes Caiapó, Vermelho Pequeno, IAC 300, IAC 400 and IAC 500. The measure of dissimilarity adopted was the Euclidean distance. Two different optimization methods were used: the Tocher optimization method and the UPGMA (Unweighted Pair-Group Method using Arithmetic Averages) hierarchical method. The genotypes Caiapó and Vermelho Pequeno were in different heterotic groups in relation to the genotypes IAC 300 and IAC 400, using the clustering method used. It was found that the yield trait was the one that most influenced the total variation. [ABSTRACT FROM AUTHOR]

The objectives of this research were to evaluate the interaction between herbicides mixed with saflufenacil for the control of barnyardgrass and to determine the effect on photosynthetic and chlorophyll fluorescence parameters. The experiment was conducted in a greenhouse in a 2x8 factorial scheme, whose factor A tested resistant and susceptible biotypes; and factor B the herbicides: saflufenacil (70 g a.i. ha-1), clomazone (180 g a.i. ha-1), imazapyr + imazapic (73.5 + 24.5 g a.i. ha-1), and cyhalofop (360 g a.i. ha-1), the mixtures of these herbicides with saflufenacil, and control without treatment. Weed control was assessed 7, 14, 21 and 28 days after herbicide application (DAA), as well as shoot dry matter at 28 DAA, photosynthetic parameters using infrared gas analyzer (IRGA), and emission of chlorophyll a fluorescence after 24 and 28 hours ofapplication of treatments, respectively, and interaction of herbicides. Combination of saflufenacil with the herbicides tested in general did not change the response of both barnyardgrass biotypes to the herbicides used. The resistant biotype showed a lower negative effect on chlorophyll fluorescence and photosynthesis parameters in the combination of herbicides with saflufenacil. The herbicide cyhalofop was effective for the control of ALS-susceptible and resistant barnyardgrass. [ABSTRACT FROM AUTHOR]

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Incubation Center for Popular Solidarity Enterprises (Cieps) has been developing actions aimed at family farming from an agroecological perspective. It is important to debate and disseminate knowledge about the respect of Landrace Seeds, such as those that can be used to increase the reach of family members and approved by land reform,in the context of the surrounding technological and business agriculture. Thus, this account showed the experience of a Conversation Circle which main objective was the socialization of knowledge and the exchange of experiences on Landrace seeds. The Conversation Circle took place during the V University Day in Defense of Land Reform, in 2019, at the Federal University of Uberlândia, State of Minas Gerais, Brazil. Some discussion points and reports from participants were presented, subdivided into the following themes: productive independence; genetic preservation and starting a seed bank. Bringing the theme Landrace Seeds to be discussed with family farmers and settlers from the land reform in times of consolidated dominance of technology packages recommended by the conventional market and often inaccessible to the producer, contributed to enable their activities and enable social economic development independently. [ABSTRACT FROM AUTHOR]

acaranda copaia (Aubl.) D. Don é uma árvore pioneira distribuída por toda Amazônia brasileira e merece atenção por ser de rápido crescimento e indicada para compor plantios destinados à regeneração de matas e capoeiras. O objetivo deste trabalho foi estimar parâmetros genéticos para caracteres de germinação de sementes em J. copaiae indicar matrizes superiores para a produção de mudas. Foram coletadas sementes de 24 matrizes de J. copaia presentes no fragmento florestal urbano do campus da Universidade Federal do Amazonas em Manaus, AM. O experimento foi desenvolvido em delineamento inteiramente casualizado, em cinco repetições de 20 sementes, totalizando 100 sementes por matriz. Todas as progênies foram avaliadas diariamente durante 60 dias em ambientes com temperaturas de 25 e 28 ºC. Foram realizadas análises de variância individual e conjunta e estimados parâmetros genéticos e ganho de seleção a partir de diferentes estratégias para os caracteres: Teste de Germinação, Primeira Contagem de Germinação, Índice de Velocidade de Germinação, Coeficiente de Velocidade de Germinação e Tempo Médio de Germinação. As progênies de J. copaia apresentaram variabilidade genética significativa para todos os caracteres de germinação avaliados em ambientes de 25 e 28 ºC. A obtenção de altos valores de herdabilidade (> 70%), assim como a presença de alta correlação genética no sentido favorável a seleção, entre todos os caracteres, indicaram condições ideais para a seleção. As matrizes 1, 2, 4, 6, 7 e 21 foram identificadas como superiores na maioria dos índices de seleção empregados, sendo indicadas para programas de conservação e produção de mudas na espécie.

Abstract The objective of this study was to estimate coefficients of repeatability, to determine the minimum number of fruits necessary for genotype selection and to estimate phenotypic correlation coefficients between morpho-agronomic characters of Theobroma grandiflorum fruits. It was evaluated twenty - two genotypes of an agroforestry system implanted in the municipality of Cantá - RR. Ten fruits per genotype were collected and evaluated for longitudinal length, transverse diameter, total weight, peel thickness, peel weight, pulp weight, placental weight and wet seed weight. Four statistical methods were used to estimate the repeatability coefficients: variance analysis, main components based on the correlation matrix and the covariance matrix, and structural analysis based on the correlation matrix. The number of measurements needed to predict the real value of the genotypes and the Pearson correlation coefficients among the characters were also estimated. The repeatability coefficients ranged from low to moderate, with 10 fruits per plant generally required, with 85% of confidence, in order to make an effective selection for most of the characters studied. There are possibilities of indirect gains for fruits with greater amount of pulp through the selection of larger and / or heavier fruits.

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Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Gene flow is important for the conservation of genetic resources to allow connectivity of geographically isolated populations and which genetic variability is reduced. Gene movement is a function of flow rate and model. Understanding how gene flow occurs can contribute to the conservation and selection of priority populations that could benefit from an eventual intervention. Simulation softwares allow making inferences about past events based on current datasets or predict future phenomena under real genetic scenarios. Adverse phenomena can be predicted and actions can be taken to avoid them. The aim of this study was to identify a model and the gene flow rates that could explain genetic structure of eight forest fragments of Cabralea canjerana in development in the Brazilian Atlantic Rainforest. To do this, simulations were performed with the EASYPOP software using a microsatellite marker dataset obtained for the species by Melo and collaborators, in 2012, 2014 and 2016. We tested five models and nine migration rates and we selected the model that produced values closer to those previously obtained for them. Criteria used for selection were the observed and expected heterozygosity and the Wright's F Statistics obtained in the simulations. The gene flow model selected was the isolation by distance model that used a rate of 0.1. We observed high levels of genetic differentiation among the fragments as result of their reproductive isolation. To allow homogenization of the allelic frequencies through gene flow, the solution would be to create ecological corridors with the aim of connecting distant fragments. [ABSTRACT FROM AUTHOR]

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The use of insecticide has still been used in large scale for the control of several stored grain pests representing great risks in the development of resistance. There are several studies with Sitophilus zeamais that seek to contain their populations, but studies that analyze their genetic variability are very few. The objective of this work was to evaluate the genetic variability of S. zeamais in 10 samples from several sites, of these, eight localities are of the Brazilian territory: Tunápolis (SC), Iguatemi (PR), Piracicaba (SP), Coimbra Maracaju (MS), Canarana (MT), Jataí (GO), Picos (PI) and two localities are from Paraguay: Amambay and Pedro Juan Caballero. We used isozyme electrophoresis methodologies in starch gel to examine six enzymatic systems (AAT, ACP, GPI, HDI, MDH and ME) and in polyacrylamide gel that allowed to analyze the enzyme (EST). The conclusion of this study was that the species showed high genetic variability (He), a moderate differentiation between the samples and these were compiled in three groups. [ABSTRACT FROM AUTHOR]

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Copyright of Nativa is the property of Revista Nativa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)