Leandro Sa Gonçalves

Divergência genética em tomate estimada por marcadores RAPD em comparação com descritores multicategóricos

The 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). Mantels 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.

Algoritmo de Gower na estimativa da divergência genética em germoplasma de pimenta

The estimation of genetic variability in germplasm collections is important not only for the conservation of genetic resources, but also for plant breeding purposes. Accessions in a germplasm bank are studied based on quantitative and qualitative descriptors. However, these data are rarely considered simultaneously in joint analyses. This work aimed to study the genetic diversity among 56 Capsicum chinense accessions coming from the Germplasm Collection of the Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF). We used 44 morpho-agronomic descriptors, 37 qualitative and seven quantitative, and the Growers algorithm for the joint analysis. We used a completely randomized design with three replications and three-plant plots. Plants grew in 5 L pots. There was phenotypic variability among the chili accessions studied, mainly in fruits. Marked differences were observed in size, shape, color and total soluble solids and vitamin C contents of fruits. We used UPGMA to perform the clustering, since it was the method with the higher cophenetic correlation coefficient (r = 0.82). Accessions felt into six classes. Gowers algorithm was more efficient in clustering when qualitative instead of quantitative data were considered. It indicates that qualitative data played a crucial role in explaining the observed groupings. Joint analysis of quantitative and qualitative data resulted in greater efficiency in the determination of genetic divergence among the accessions evaluated. Therefore, such analysis is definitely a viable and important tool for understanding the variability within germplasm banks.

Stability of F 7:8 snap bean progenies in the Northern and Northwestern regions of Rio de Janeiro State

The objective of this experiment was to assess the genotypes by environment interaction for eight morphoagronomic traits in thirty F 7:8 snap bean superior lines and evaluate the pod yield stability. The experiments were carried out in the cities of Bom Jesus do Itabapoana, Campos dos Goytacazes and Itaocara, located in the Northern and Northwestern regions of Rio de Janeiro State, Brazil. Experiments were designed in randomized blocks with two replications, using the traditional method (Yates & Cochran, 1938) and the methods proposed by Plaisted & Peterson (1959), Wricke (1965), Kang & Phan (1991) and Lin & Binns (1988), as well. Only the average fiber content in pods revealed no significant genotype x environment interaction, whereas most of the traits showed simple interaction, including pod yield. The results obtained using the methods of Plaisted & Peterson (1959) and Wricke (1965) agreed to a far extent and had a moderate estimate (0.6131) in relation to the traditional method. Both methods highlighted genotypes with pod yield close to the general average, i.e., around 7,546.46 kg ha -1 . Kang & Phan’s (1991) algorithm was more efficient in optimizing the stability estimates obtained using the methods of Plaisted & Peterson (1959) and Wricke (1965) than the traditional method. Lin & Binns’ (1988) procedure revealed the most stable, responsive and productive progenies. Progenies 04, 03 and 10 stood out in all environments.

Collection and morphological characterization of sweet potato landraces in north of Rio de Janeiro state

Os agricultores tradicionais tem um papel fundamental na conservacao dos recursos geneticos vegetais e a coleta de germoplasma mantido por esses produtores e muito importante para evitar a perda da variabilidade genetica. Os objetivos deste trabalho foram coletar germoplasma de batata-doce em propriedades rurais situadas no norte do estado do Rio de Janeiro; levantar informacoes quanto ao perfil dos produtores rurais visitados durante as coletas, e caracterizar morfologicamente as variedades locais de batata-doce coletadas. Em seis viagens de coleta foram visitadas 53 propriedades rurais, e coletados 46 acessos. Em todas as visitas foi possivel entrevistar o produtor por meio de questionario contendo dez itens. Para a caracterizacao, foram usados seis caracteres de raiz e oito da parte aerea. A analise dos dados foi efetuada com o uso da distância de Cole-Rodgers e o agrupamento foi gerado com o metodo UPGMA. Foi constatado predominio da agricultura familiar, voltada para subsistencia, sendo que 72% dos agricultores cultivavam a batata-doce ha mais de uma decada, o que evidencia a tradicao de cultivo desta hortalica em pequenas areas na regiao. A caracterizacao morfologica foi eficiente para detectar a variabilidade genetica entre os acessos, demonstrando que os agricultores tradicionais dos municipios de Campos dos Goytacazes e Sao Joao da Barra detem genotipos de batata-doce com expressiva diversidade genetica em suas propriedades. Nao foi detectada correlacao entre a distância genetica e os locais de coleta.

Potencial agronômico e divergência genética entre genótipos de berinjela nas condições do Caribe Colombiano

Agronomic potential and genetic divergence among eggplant genotypes in the Colombian Caribbean region We evaluated 24 genotypes (hybrids, cultivars and landraces) of eggplant related to yield traits in the Colombian Caribbean region, to quantify the genetic divergence among these genotypes and to indicate possible crosses. With the results of the genetic diversity and agronomic traits we intend to initiate a program of eggplant breeding in that region. A randomized block design with three replications was used. The analyzed variables were fruit length, number of fruits per plant, mean fruit weight, yield, fruit firmness and plant height. The data were submitted to variance analysis and the averages grouped by Scott-Knott test. A multivariate analysis was also performed using different methods of hierarchical clustering and canonical variables. There was high divergence among the studied genotypes even when considered within hybrids, cultivars and landraces, with highest variability among the cultivars and hybrids followed by the landraces. The UPGMA method was more reliable than Ward and Single Linkage methods since UPGMA presented greater value of Cophenetic Correlation Coefficient (CCC). Using pseudo-F and pseudo-t 2 criteria the maximum point was reached when four clusters were formed, being considered the ideal number of groups for the UPGMA. There was agreement among the groups formed for UPGMA analysis and canonic variables. Crosses between CC08 x CC02; CC08 x EU01 and CC08 x C016 may be recommended to start an eggplant breeding program aiming to improve yield and fruit firmness.

Determining the inheritance of agronomic traits in chili pepper

O genero Capsicum e amplamente estudado em muitos paises, porem a maioria das pesquisas se concentra em C. annuum. Apesar de sua importância como potencial recurso genetico para a resistencia a doencas e qualidade dos frutos, os estudos sobre a genetica e o melhoramento de C. baccatum var. pendulum ainda sao escassos, alem de ser considerada uma especie subexplorada. Este trabalho teve como objetivos: estudar a heranca de sete caracteristicas agronomicas; estimar os parâmetros geneticos para esses caracteres por meio da analise de medias de geracoes e verificar a existencia de gene de efeito maior e de possiveis poligenes de efeitos aditivos e nao aditivos, utilizando-se o metodo da maxima verossimilhanca com auxilio do programa Monogen. As caracteristicas agronomicas avaliadas foram: numero de frutos por planta (NFP); massa media de frutos por planta (MMF); comprimento do fruto (CPF); diâmetro do fruto (DFR); espessura de polpa do fruto (EPF); teor de solidos soluveis totais (TSS) e massa seca de fruto (MSF). Houve diferenca significativa entre as geracoes (P1, P2, F1, F2, RC1 e RC2) para todas as caracteristicas avaliadas. As estimativas da herdabilidade no sentido restrito variaram de 45% (NFP) a 75% (DFR). Constatou-se que a acao genica de dominância parcial esta envolvida no controle genetico das caracteristicas CPF e DFR, enquanto que a acao aditiva foi observada para NFP, EPF e TSS, dominância completa para MSF e sobredominância para MMF. O modelo aditivo-dominante foi suficiente para explicar os resultados obtidos para todas as caracteristicas avaliadas. Ja pelo metodo da maxima verossimilhanca pode-se identificar a existencia de poligenes com efeitos aditivos e de dominância nas caracteristicas TSS, EPF e MSF. A acao de gene de efeito maior foi detectada para CPF e NFP. Os resultados apontam a complexidade da heranca das caracteristicas avaliadas, com presenca de gene de efeito maior envolvido.

Heterosis and combining ability of dual-purpose tomato hybrids developed to meet family farmers' needs in Brazil and Mozambique

ABSTRACT Rhizoctonia root rot, caused by Rhizoctonia solani, is a common disease in areas intensively cultivated with melon (Cucumis melo) in the Northeastern Brazil. The objective of this study was to identify and characterize morphologically resistance sources of melon to R. solani. In the first trial, twenty-two melon accessions collected in the Northeastern Brazil were evaluated for their reaction to the isolate RS-21, in an experiment with the completely randomized design and five replications. The resistant accessions of the first experiment and 13 inbred lines of the ACP x AF -646 cross were evaluated for their reaction to the RS-22 and RS-23 isolates on a second trial carried out in a randomized design with five replications. The accessions T-A-08, T-A-09, T-A-19 and the line ACP-AF-06 were identified as sources of resistance. In both inoculation trials, seeds were planted in infested soil (50 mg of colonized rice grains/1.0 kg of soil). The evaluation of accessions was performed after 45 days, with a score scale from 0.0 to 4.0 to cluster genotypes in five classes. Resistance sources were characterized morphologically in an essay carried out in randomized block design with three replications. The characterization identified the T-A-08 and T-A-19 accessions as belonging to the botanical variety momordica and the T-A-09 accession and the ACP-AF-06 inbred line as belonging to the varieties acidulus and inodorus, respectively. Resistance sources may be used in future breeding programs aiming to obtain genotypes (inbred lines and hybrids) resistant to R. solani.

Registration and protection of vegetables in Brazil between 1998 and 2014

This study aimed to realize a broad survey of the registry and protection numbers concerning different vegetables species in the Ministerio da Agricultura Pecuaria e Abastecimento - MAPA (Brazilian Ministry of Agriculture, Livestock and Food Supply) and to investigate the participation of public and private institutions. Therefore, 34 vegetable crops of economic and social importance were selected, these being divided into tuberous, herbaceous (leaves, flowers and stems) and fruits. Data for the study were obtained from the Registro Nacional de Cultivares - RNC (Brazilian National Register of Cultivars) and the Servico Nacional de Protecao de Cultivares - SNPC (Brazilian National Service of Plant Variety Protection, available in real time the MAPA site. The survey was carried out between 1998 and 2014. We verified 7174 registry and 147 protections, tomato, Capsicum spp. (sweet and chili peppers), lettuce and melon presenting the highest number of records, while the potato and lettuce had the highest protection numbers. In relation to the participation of private and public institutions in the RNC and SPNC, there was a marked predominance of private institutions was observed, with 93.23 and 87.75%, respectively. The public sector obtained 226 registries and 18 protections, Embrapa (Brazilian Agricultural Research Corporation) being highlighted with 57.22 and 72.22% of the registries and protections, respectively. Public-private partnerships have had little contribution in the generation of new cultivars. This result finds the lack of integration between the public and private sector, which should work in greater proportions jointly for achieving technological breakthroughs.