R. M. E. Borges

Produtividade da cultura da abóbora em diferentes densidades de plantio no Vale do São Francisco

Pumpkin is extensively cultivated and consumed in Brazil, in a special way in Northeast Region. The spacing between and within the line is crucial for the development and production of the crop. The experiment was carried out in Petrolina, Pernambuco state, Brazil, from May to September, 2005. We evaluated different planting spacings on yield of pumpkin accessions and one cultivar. The experimental design was complete randomized blocks in factorial scheme 5x3, consisting of five selected accessions from the Germplasm Active Bank of Pumpkin (accessions A422, A612, A620 and A627) and Jacarezinho cultivar as control, and three spacing values within planting rows (4x1; 4x2 and 4x3 m) with four replications. Highest yield was presented by accession A612 (17.3 t ha-1), followed by accession A422 (15.2 t ha-1), with worst performance from cultivar Jacarezinho (12.2 t ha-1), without differing from the other treatments. For plant spacing the highest yields were obtained in the smaller spacing (4x1 m) with 18.2 t ha-1, and lower yield in the spacing of 4x3 m (11.9 t ha-1). The accession A612 showed the highest fresh fruit mass (3.5 kg fruit-1) without statistical difference from accession A422 (3.2 kg fruit-1). The cultivar Jacarezinho and accession A620 with respectively 1.9 and 2.0 kg fruit-1 presented the lowest values of fresh fruit mass as well as the largest number of fruits per plant (4.7 and 4.6, respectively).

Preliminary characterization of Psidium germplasm in different Brazilian ecogeographic regions

O objetivo deste trabalho foi caracterizar 119 acessos de goiabeira e 40 acessos de aracazeiro identificados em 35 ecorregioes brasileiras, de acordo com descritores da International Union for the Protection of New Varieties of Plants (UPOV). A maioria dos acessos de aracazeiro apresentou grandes espacos entre as nervuras da folha, enquanto os de goiabeira apresentaram espacos pequenos. Os frutos de aracazeiro foram classificados como pequenos, enquanto os de goiabeira apresentaram tamanho de medio a grande. A maioria dos acessos de aracazeiro (91%) apresentou cor branca para a polpa do fruto, enquanto 58% dos de goiabeira apresentaram cor de rosa-claro a rosa-escuro. As diferencas nos frutos entre Psidium selvagens e domesticados indicam que os frutos foram os mais alterados pela selecao artificial.

Divergência fenotípica entre acessos de uvas de mesa no Semi-Árido brasileiro

O objetivo deste trabalho foi avaliar a divergencia fenotipica em uvas da Colecao da Embrapa Semi-Arido, com base em oito variaveis morfoagronomicas avaliadas nos anos 2005 e 2006. Nas uvas com sementes, a analise por componentes principais identificou oito grupos contrastantes. As variaveis mais relevantes, quanto a divergencia genetica, foram peso e comprimento de bagas. Em uvas sem sementes, formou-se apenas um grupo, e as variaveis mais relevantes foram peso de bagas e producao. A distância euclidiana media padronizada no grupo com sementes mostrou que 41% dos acessos apresentaram estimativas acima da media geral. No grupo sem sementes, o percentual foi de 47%. Foi observada concordância de resultados com os componentes principais. Pelo UPGMA, formaram-se tres grandes grupos das uvas com sementes: o primeiro, com 14 acessos; o segundo, com seis acessos e similaridade de 56%; e o terceiro, com 19 acessos e similaridade de 73%. Das uvas sem sementes, formaram-se tres grupos: um, com 11 acessos e similaridade de 59%; outro, com sete acessos e similaridade de 58%; e o terceiro com apenas um acesso. Sugere-se que os acessos com maior divergencia quanto aos caracteres estudados sejam utilizados para a obtencao de hibridos de videira.

Phenotypic divergence among wine grap accessions in the semi-arid region of Brazil

The objective was to estimate the phenotypic divergence in wine grapes based on 11 agronomic variables. Two contrasting groups, both for white as for red grapes, were formed by principal component analysis. In white grapes, greatest divergence was observed in the accessions Baco Blanc, Campanario and Palomino. In red grapes, the most divergent were Aramon and Tannat; Castelao and Mars. The standardized Euclidean distance indicated 52.4 and 40.0% white and red grape accessions, respectively, with means exceeding the overall mean. By UPGMA, four major groups were formed for white and red grapes. Both principal component analysis and UPGMA showed that the genealogy of the accessions Petite Sirah FR and Petite Sirah RS is similar. The accessions with most divergence in the traits studied should be used to produce hybrids, as well as for selection of accessions with a view to regional wine making.

Phenotypic variability among pumpkin accessions in the Brazilian semiarid

The aim of this study was to estimate the phenotypic divergence among fourteen pumpkins accessions of the cucurbits Germplasm Active Bank of Embrapa Semiarido, in order to support breeding program to these species. Nine morphoagronomic descriptors were analyzed by the principal components and by UPGMA techniques. In the analysis of principal components, the formation of three contrasting clusters was observed, each one composed of two accessions. There occurred also the formation of one core group composed of five accessions, being the accessions called 683 and 684 collected in Bahia and the other in Maranhao. The most divergent accessions were 620, 624 and 748. The variables of the greatest contribution to the genetic divergence were diameter, weight and average length of the fruit. In the UPGMA analysis, obtained from the symmetric matrices generated by the Mahalanobis distance for the nine descriptors, there was the formation of one core group, composed of ten accessions, whose similarity was 45.71%, with geographically divergent accessions presenting the greatest similarity. Three accessions were not clustered with others. The study identified phenotypic variability for the analyzed characters and the absence of relationship between place of collection and phenotypic diversity.