ABSTRACT. Capsicum species are frequently described in terms of genetic divergence, considering morphological, agronomic, and molecular databases. However, descriptions of genetic differences based on anatomical characters are rare. We examined the anatomy and the micromorphology of vegetative and reproductive organs of several Capsicum species. Four Capsicum accessions representing the species C. annuum var. annuum, C. baccatum var. pendulum, C. chinense, and C. frutescens were cultivated in a greenhouse; leaves, fruits and seeds were sampled and their organ structure analyzed by light and scanning electronic microscopy. Molecular accession characterization was made using ISSR markers. Polymorphism was observed among tector trichomes and also in fruit color and shape. High variability among accessions was detected by ISSR markers. Although the species studied Characterization of Capsicum species present a wide morphological and molecular variability, this variability was not reflected in anatomical features.

ABSTRACT. Small farmers have played an important role in maintaining genetic resources of traditional varieties. Collecting and characterizing germplasm, especially landraces and heirloom varieties, are strategic activities that would create a knowledge base describing the traditional varieties of a given region and reduce the risk of genetic erosion. The objectives of this work were as follows: collect sweet potato roots from rural properties and local markets in Rio de Janeiro State, Brazil; characterize the accessions using RAPD and ISSR molecular markers, comparing the efficiency in discrimination of these two types of molecular markers; and estimate the genetic variability of the population. Fifty-nine samples from rural properties and 19 from local markets were studied. A matrix of binary data was developed to analyze the molecular data using the Jaccard index to estimate genetic differences among accessions, and clusters were made using the UPGMA method. The molecular techniques detected genetic variability among the accessions, with cophenetic correlation coefficients (CCC) of 0.80 for RAPDs and 0.89 for ISSRs. The RAPD and ISSR marker results corresponded well, with a correlation of 0.55. All of the accessions were considered distinct, which demonstrates that traditional farmers maintain sweet potato genotypes that have good genetic diversity.Keywords: genetic resources, germplasm characterization, genetic variability, heirloom seeds.Comparação dos marcadores RAPD e ISSR na estimativa da diversideade genética entre acessos de batata-doce (Ipomoea batatas (L.) Lam.) RESUMO. Os pequenos agricultores têm um importante papel na manutenção de recursos genéticos das variedades tradicionais. A coleta e caracterização de germoplasma, especialmente variedades locais e heirloom são atividades estratégicas que permitem o desenvolvimento de conhecimentos sobre as variedades tradicionais de uma determinada região reduzindo o risco de erosão genética. Os objetivos deste trabalho foram: coletar raízes de batata-doce em propriedades rurais e estabelecimentos comerciais do Estado do Rio de Janeiro, Brasil; caracterizar os acessos usando os marcadores moleculares RAPD e ISSR; e estimar a variabilidade genética na população. Cinquenta e nove amostras coletadas em propriedades rurais e em 19 estabelecimentos comerciais foram estudadas. Uma matriz de dados binários foi desenvolvida para análise dos dados moleculares, usando o índice de Jaccard para estimar a dissimilaridade genética entre os acessos, e os grupos foram obtidos usando o método UPGMA. As técnicas moleculares detectaram variabilidade genética entre os acessos, com correlação cofenética de 0,80 para RAPD e 0,89 para ISSR. O resultado obtido com RAPD e ISSR foi correspondente, com uma correlação de 0,55. Todos os acessos coletados foram considerados distintos, o que demonstra que os agricultores tradicionais da região Norte Fluminense detêm genótipos de batata-doce com expressiva diversidade genética.Palavras-chave: recursos genéticos, caracterização de germoplas...

Genetic divergence among tomato accessions using RAPD markers and its comparison with multicategoric descriptorsThe estimation of genetic variability in a germplasm bank is important not only for the conservation of the genetic resources, but also for applications in plant breeding. The genetic divergence among 78 tomato accessions was studied, based on 74 RAPD markers. Also, a correlation between the molecular profile and 27 morphological and agronomic data was performed. Cluster analysis (UPGMA), used to study the data, resulted in 13 groups that were correlated with five descriptors (growth habit, leaf type, fruit color, locule number, and fruit shape). Some groups had particularities, such as group IV that assembled accessions with pear shape fruits; group VII, that clustered accessions with bacterial wilt resistance, and group IX, that gathered accessions with potato leaf type. Bootstrap analysis revealed few consistent clusters. The results showed a positive and significant correlation between the matrixes generated out of qualitative and molecular data (t = 14.02). Mantel's correlation was highly significant, but with a low value (r = 0.39), which suggests that for a wise use of the germplasm bank accessions, both characterization, molecular and morphoagronomic, should be carried out.

ABSTRACT

The traditional farmers play an important role in plant genetic resources conservation. Collecting the germplasm maintained by these farmers is a very important action to avoid genetic variability losses. The goals of this work were to collect sweet potato from farms in the north of Rio de Janeiro state; to gather information regarding to the farmers profile, and to characterize the sweet potato landraces collected using morphological descriptors. Fifty three farms were visited in six collection expedition and 46 accessions were collected. During the visits the farmers were interviewed using a query with ten items. Six root traits and eight descriptors for vegetative parts were used for morphological characterization. The data were analyzed based on Cole-Rodgers distance and clustering was done with UPGMA method. Familiar agriculture with subsistence objective was observed and sweet potato was cultivated by 72% of the farmers at least for more than a decade, supporting the observation that this vegetable is traditionally cultivated in small areas in the specific region. The morphological characterization was efficient to detect genetic variability among accessions, revealing that traditional farmers from Campos dos Goytacazes and São João da Barra are responsible for sweet potato genotypes conservation with expressive genetic diversity in their properties. There was no relationship between genetic distance and collecting areas.

ABSTRACT. Several plant organs contain proteinase inhibitors, which are produced during normal plant development or are induced upon pathogen attack to suppress the enzymatic activity of phytopathogenic microorganisms. In this study, we examined the presence of proteinase inhibitors, specifically trypsin inhibitors, in the leaf extract of Capsicum baccatum var. pendulum inoculated with PepYMV (Pepper yellow mosaic virus). Leaf extract from plants with the accession number UENF 1624, which is resistant to PepYMV, was collected at 7 different times (0, 24, 48, 72, 96, 120, and 144 h). Seedlings inoculated with PepYMV and control seedlings were grown in a growth chamber. Protein extract from leaf samples was partially purified by reversedphase chromatography using a C2/C18 column. Residual trypsin activity was assayed to detect inhibitors followed by Tricine-SDS-PAGE analysis to determine the N-terminal peptide sequence. Based on trypsin inhibitor assays, trypsin inhibitors are likely constitutively synthesized in C. baccatum var. pendulum leaf tissue. These inhibitors are likely a defense mechanism for the C. baccatum var. pendulumPepYMV pathosystem.

ABSTRACT. Genetic mapping is very useful for dissecting complex agronomic traits. Genetic mapping allows for identification of quantitative trait loci (QTL), provide knowledge on a gene position and its adjacent region, and enable prediction of evolutionary mechanisms, in addition to contributing to synteny studies. The aim of this study was to predict genetic values associated with different agronomic traits evaluated in an F 2 population of Capsicum baccatum var. pendulum. Previously, a reference genetic map for C. baccatum was constructed, which included 183 markers (42 microsatellite, 85 inter-simple sequence repeat, and 56 random amplification of polymorphic DNA) arranged in 16 linkage groups. The map was used to identify QTL associated with 11 agronomic traits, including plant height, crown diameter, number of days to flowering, days to fruiting, number of fruits per plant, average fruit weight, fruit length, fruit diameter, fruit QTLs for agronomic traits in C. baccatum var. pendulum pulp thickness, soluble solids, and fruit dry weight. QTL mapping was performed by standard interval mapping. The number of small QTL effects ranged from 3-11, with a total of 61 QTL detected in 9 linkage groups. This is the first report involving QTL analysis for C. baccatum species.

A batata-doce possui grande potencial econômico e nutricional, sendo de grande relevância para a geração de renda de agricultores familiares. Neste contexto, a caracterização deste recurso genético deve ser prioridade em programas de melhoramento da olerícola. Os agricultores tradicionais do município de Campos dos Goytacazes e São João da Barra detêm genótipos de batata-doce com expressiva diversidade genética em suas propriedades. O presente trabalho objetivou coletar raízes e ramas de batata-doce em propriedades rurais e estabelecimentos comerciais da região Norte do Estado do Rio de Janeiro, caracterizar os acessos coletados com base em marcadores morfoagronômicos e estimar a divergência genética da população estudada. Para os dados quantitativos de raiz foi utilizada a Distância Euclidiana Média, obtendo-se a matriz de dissimilaridade, e o agrupamento foi realizado com auxílio do método de agrupamento das divergências médias (UPGMA).  Observou-se variação para os dez caracteres qualitativos de raiz avaliados, confirmando a alta variabilidade fenotípica dos genótipos de batata-doce estudados. Não foi detectada correlação entre as distâncias geográficas e as distâncias genéticas mensuradas pelo índice de dissimilaridade de Jaccard, configurando uma ausência de estruturação entre a variabilidade genética e o local de coleta, o que pode ser explicado pelo método de propagação assexuado e à prática de constantes trocas entre os produtores rurais da região. A caracterização morfoagronômica quantitativa e qualitativa foi eficiente para estimar a diversidade genética existente entre os acessos de batata-doce cultivados e comercializados na região norte do estado do Rio de Janeiro.