AbstrAct-The aim of this study was to characterize Passiflora spp. accessions and its genetic diversity based on quantitative morphological descriptors of flowers and fruits. The study was conducted at Embrapa Cerrados, Planaltina-DF. Fifteen Passiflora spp. accessions were characterized using 14 quantitative morphological descriptors. Genetic distances among accessions were estimated based on Mahalanobis' generalized distance. Cluster analysis via dendrogram and graphic dispersion was analyzed. The relative contribution of characters for accession divergence was also calculated. The morphoagronomic characterization based on quantitative descriptors of flowers and fruits contributed to the differentiation of Passiflora spp. accessions, serving as an important tool for variability quantification. This information is useful to perform Passiflora spp. characterization and genetic diversity studies. Index terms: multivariate analysis, Passifloraceae, genetic resources.DIVErsIDADE GENÉtIcA E MOrFOAGrONÔMIcA DE Passiflora spp. bAsEADA EM VArIÁVEIs QUANtItAtIVAs DAs FLOrEs E FrUtOs rEsUMO-Objetivou-se caracterizar acessos de Passiflora spp. e sua diversidade genética baseada em descritores morfoagronômicos quantitativos de flores e frutos. O estudo foi realizado na EMBRAPA Cerrados, Planaltina-DF. Foram caracterizados 15 acessos de Passiflora spp. utilizando 14 descritores morfoagronômicos quantitativos. Distâncias genéticas entre os acessos foram estimadas com base na Distância de Mahalanobis. Análise de agrupamento via dendrograma e dispersão gráfica via coordenadas principais foram analisadas. Foi calculada, também, a contribuição relativa dos caracteres para divergência genética dos acessos analisados. A caracterização morfoagronômica baseada em descritores quantitativos de flores e frutos contribuiu para a diferenciação fenotípica entre os acessos Passiflora spp., servindo como importante instrumento para quantificar a variabilidade. Essa caracterização é importante para estudos mais completos de caracterização e diversidade genética do gênero Passiflora. termos para indexação: análise multivariada, Passifloraceae, recursos genéticos.1 .

Secondary compounds have allelopathic action on germination and growth, and initial development of seedlings and beggar tick can have its germination and growth affected by the action of allelopathic extracts. Thus, this work aimed to evaluate the allelopathic potential of Brachiaria (Brachiaria brizantha), sunflower (Helianthus annuus) and sorghum extracts (Sorghum bicolor) on germination and initial growth of beggar ticks (Bidens pilosa). For this, an experiment was conducted in a completely randomized design with four treatments and six replicates and brachiaria, sunflower and sorghum extracts and control (distilled water) treatments. Extracts were obtained using 200 g of plant material and 1,000 mL of distilled water. Seeds were distributed in gerbox containing two sheets of germitest paper moistened with treatments and taken to germination chamber. Germination was daily monitored, and ten days after, initial growth was evaluated. Extracts did not reduce germination. However, they caused increase in germination time, mainly by brachiaria extract. Seedlings submitted to brachiaria and sorghum extracts showed lower growth. Brachiaria and sorghum extracts showed no action on germination, but controlled the initial growth of beggar tick, being potential natural herbicides.

The Embrapa Cerrados pitaya breeding program developed five superior genotypes of different species. The objective of this work was to evaluate the yield capacity of these five pitaya genotypes under the edaphoclimatic conditions of the Federal District. The experiment was carried out at the Embrapa Cerrados in Planaltina, DF. The five selected pitaya genotypes were evaluated, as well as a parent genotype used in the breeding program. Length (CF), diameter (DF) and mass (MF) of all fruits were evaluated, as well as the length/diameter ratio (CF.DF-1), number of fruits per plant (NF.PL-1), production per plant (kg.PL-1) and estimated productivity (t.ha-1). BRS Luz do Cerrado and BRS Lua do Cerrado presented larger and heavier fruits, while BRS Minipitaya do Cerrado presented the smallest fruits. CPAC Roxa and BRS Granada do Cerrado presented more rounded fruits. BRS Granada do Cerrado had the highest yield capacity in the two evaluated crops. The results obtained prove the importance of genetic breeding and the selection of superior genotypes more adapted to the region of cultivation, in order to guarantee greater profitability and products of better quality to rural producers and consumers.

The Passiflora genus comprises more than 500 species that are used for food, industrial, ornamental, and pharmaceutical purposes. The sour passion fruit (P. edulis Sims) has low genetic variability for disease resistance, and the use of wild species in the cross-breeding basis is a promising alternative for introgression of resistance genes. The objective of this study was to characterize multispecific hybrids and wild materials with potential to be used as parents in passion fruit genetic breeding programs, using microsatellite markers. Genomic DNA from 33 accessions was extracted and analyzed using 23 microsatellite markers, which were used to estimate the genetic dissimilarities among accessions. The genetic dissimilarity matrices were used to perform clustering analysis by dendrogram using the Unweighted Pair-Group Method as grouping criterion and by graphic dispersion based on multidimensional scale, using the principal coordinates method. Genetic distances between accessions ranged from 0.067 to 1.00. The markers indicated genetic variability among the studied accessions and also the efficiency of the recurrent genome recovery within the backcross program. The genetic structure among the accessions shows the clustering tendency between the wild accessions of P. hatschbachii and P. quadrifaria and the accessions obtained by crossing these species. The same occurred for P. incarnata and P. edulis accessions. The knowledge generated by the molecular characterization provides information on the diversity of accessions and contributes to the work of breeders in the selection of parents.

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