RESUMO -O conhecimento da variabilidade genética e da relação entre diferentes acessos de aceroleira é importante para maximizar o uso dos recursos genéticos para futuros programas de melhoramento. O objetivo deste trabalho foi avaliar a divergência genética entre 48 acessos de aceroleira, por meio de marcadores moleculares RAPD e características morfoagronômicas. Foram utilizados 25 iniciadores, possibilitando obter 108 marcadores, sendo observadas 92 marcas polimórficas. Os marcadores obtidos foram analisados, usando os métodos de otimização de Tocher e hierárquico UPGMA, que gerou um dendrograma utilizando o índice de Jaccard. Os resultados mostraram uma concordância parcial entre os métodos de agrupamentos estudados, com a formação de 14 grupos. Os acessos ACE 023 e ACE 033 foram os mais distintos, apresentando distância genética de 0,58. A análise comparativa dos agrupamentos revelou que os marcadores RAPD, associados com características morfoagronômicas, foram eficientes para a discriminação dos acessos e que houve uma variabilidade genética potencial para o programa de melhoramento genético e informações úteis, como a indicação de acessos promissores para avaliação clonal. Termos para indexação: polimorfismo; teor de ácido ascórbico; variabilidade genética. GENETIC DIVERSITY OF BARBADOS CHERRY (Malphigia emarginata D. C.), WITH RAPD MOLECULAR MARKERS AND MORPHO-AGRONOMICAL CHARACTERISTICSABSTRACT -The knowledge on genetic variability and the relationship among different Barbados cherry accesses is important to maximize the resources for the future genetic breeding. The objective of this work was to determine the genetic variability among 48 accessions of Barbados cherry evaluated using RAPD as DNA markers and morpho-agronomical characteristics. It was used 25 primers, making it possible to obtain 108 markers and to generate 92 different polymorphic products. The obtained markers were of analyzed by the method of Tocher and UPGMA what generated a dendrogram using the Jaccard index. There was a concordance among the studied methods with the formation of 14 groups. The accessions ACE 023 and ACE 033 were the most distinct, presenting a genetic dissimilarity of 0.58. The results allowed to us to conclude that RAPD marker associated with morpho-agronomical characteristics were efficient to discriminate the genetic relationship among the accessions of Barbados cherry and the divergent accessions should be useful in the use of genetic breeding and six of them were recommended for future clonal evaluation as varieties and clonal propagation.

Castor bean husk as substrate for plantsCastor bean husk (CBH) is a residue generated in large amounts in the castor bean processing. The aim of this study was to evaluate the chemical and physical characteristics of CBH and its effect used as substrate for plants. CBH characteristics were evaluated in a (2x3) factorial randomized block design, consisting of a combination of two husk types (CBH fresh and composted) and three grades (mesh 3 mm, 5 mm e 10 mm). Macro and micronutrient contents, pH, electrical conductivity, wet density, dry density, total porosity and air space were evaluated. The evaluation of CBH as substrate for plant growth was carried out using tomato (Lycopersicon esculentum Mill.) seedlings and golden dew drop (Duranta repens L.) cuttings as indicator species. Tomato seedlings were grown on CBH 3 mm grade, fresh or composted, mixed to Plantmax ® in five ratios [0:100; 25:75; 50:50; 75:25; 100:0 (v/v)]. Rooting of golden dew drop cuttings was carried out on CBH, fresh or composted, using three grades (3, 5 and 10 mm). The composted 3 mm grade Casca do fruto da mamoneira como substrato para as plantas 1A casca do fruto da mamoneira (CFM) é um resíduo gerado, em grande quantidade, no beneficiamento da mamona. O objetivo desta pesquisa foi avaliar as características físicas e químicas da CFM e seu efeito, como substrato, para plantas. A avaliação das características da CFM foi realizada em um experimento fatorial (2x3), constituído da combinação de dois tipos de casca (CFM in natura e compostada) e três granulometrias (peneiras 3, 5 e 10 mm de malha), em delineamento de blocos ao acaso. Os teores de macro e micronutrientes, condutividade elétrica (CE), pH, densidade seca (DS), densidade úmida (DU), porosidade total (PT) e espaço de aeração (EA) foram avaliados. A avaliação da CFM

ABSTRACT. Current demands for the genetic breeding of castor bean include the adaptation of genotypes to low altitudes to expand the potential areas of cultivation. This study was conducted to evaluate the response of different genotypes of castor bean that were sown in winter and summer at a low altitude. The study was conducted in northwestern Rio de Janeiro State at an altitude of 60 m. The treatments consisted of genotypes IAC 80, AL Guarany 2002, BRS 149 Nordestina, BRS 188 Paraguaçu, Savana, Lyra, Mirante 10, IAC 226, Cafelista, G1, V1, and T1 with spaces of 2.0 m between rows, 1.0 m between plants, and one plant per hole. The plant height, number and length of racemes, number of fruits per raceme, seed yield, and incidence of gray mold were determined. The highest yields in both seasons were obtained by the genotypes BRS 149 Nordestina, G1, BRS 188 Paraguaçu, and IAC 226. The genotypes Savannah and Lyra had the lowest yields in both cultivation seasons. The genotypes responded differently to the environmental conditions depending on the growing season, and the spring-summer period was found to be more favorable at the low altitude of the study site.

The cultivation of the castor bean plant is prominent and important because of its potential for producing vegetable oils with special properties. However, research on cultivating castor bean plants is scarce, especially in areas with altitudes of 300 m or below. Moreover, the currently available cultivars have not been widely tested in Brazil. Thus, the aim of this study was to evaluate the response of the castor bean cultivar BRS Nordestina to different spacings at low altitudes during two cropping seasons. The study was conducted in the municipality of Itaocara, in the northwest Fluminense region, Brazil, which has an altitude of 60 m. The treatments consisted of five row spacings (1.5, 2.0, 2.5, 3.0 and 3.5 m) with 1 m between plants. The plants were cultivated in the 2007/2008 spring/summer season or in the 2008 autumn/winter season. A randomised block design with four replicates was used. The following parameters were assessed: plant height, height of insertion of primary raceme, number of racemes per plant, raceme length, number of fruits per raceme and grain yield. The spacing of 2.5 m between rows had the highest yield of castor beans during the two cropping seasons. The average yield of the cultivar BRS Nordestina indicates its potential for cultivation in northern Rio de Janeiro, below an altitude of 300 m. The yield was higher during the summer cropping season. The less-dense arrangement of the plant population contributed to the cultivation of plants with more racemes in both growing seasons.

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