Panama disease, caused by Fusarium oxysporum f. sp. cubense (Foc), is ranked among the most destructive diseases of banana. The use of resistant varieties is the most desirable and effective control measure. Information on the pathogen population structure is essential, as durability of the resistance and effective cultivar deployment are strongly linked to this structure. In this study, 214 Foc isolates from different banana producing states in three regions of Brazil (northeastern, southeastern and southern) were analysed. Initially, nine microsatellite markers (SSR) were tested, which revealed 52 distinct haplotypes distributed in the different geographical regions and cultivars. While amova analysis showed that 68·01% of the total variation occurred within states, correlation between genetic and geographical distances was only found in the southern region. Results indicated that isolates from different states comprise a single population, which is predominantly clonal. When isolates representing different haplotypes were inoculated in four banana cultivars, differences in severity were found, with the high severity values being caused by isolates from haplotypes H7, H31 and H41. The diversity found here points to the need for additional studies, as this characteristic may be related to Foc's evolutionary potential and possibly to its ability to overcome the resistance from breeding programme‐generated cultivars. This is the most comprehensive study on population biology of Foc in Brazil.

RESUMO -A demanda por frutos orgânicos cresce a cada ano em todo o mundo, e a bananicultura pode apresentar crescimento nesse setor, tanto no mercado interno quanto no externo. No entanto, há falta de informações que justifiquem a produção de frutos orgânicos e que atestem as vantagens e desvantagens dos dois sistemas de cultivo. Assim, o objetivo deste trabalho foi avaliar bananas provenientes de sistema de cultivo convencional e orgânico quanto aos seus aspectos físicos e químicos. Utilizaram-se as cultivares Caipira (AAA), Maravilha (AAAB), Pacovan Ken (AAAB), Prata-Anã (AAB), Thap Maeo (AAB) e Tropical (AAAB). No cultivo orgânico, foi utilizada cobertura verde (Canavalia ensiformis e Arachis pintoi) e fertilização com composto orgânico, fosfato natural, torta de mamona e cinzas de madeira. No cultivo convencional, não se utilizou cobertura verde, procedendo-se apenas a fertilização química com ureia (100 kg ha -1 ), superfosfato simples (280 kg ha -1 ) e cloreto de potássio (540 kg ha -1 ). Foram avaliados os atributos físicos: peso de frutos com e sem casca, diâmetro e comprimento do fruto, peso da penca, número de frutos por penca e espessura da casca; e os atributos químicos: sólidos solúveis, acidez titulável, ratio, pH, umidade e os teores de açúcares solúveis (redutores, não redutores e totais). O delineamento utilizado foi o inteiramente casualizado, com 3 repetições, e os dados submetidos à análise de variância e teste de Tukey, a 5% de probabilidade. Pode-se afirmar que o manejo convencional ou orgânico não alterou as características físico-químicas das bananas, com exceção para os teores de umidade e de açúcares não redutores, sólidos solúveis, comprimento e diâmetro do fruto para algumas cultivares. Termos para Indexação: Musa spp., banana orgânica, genótipos melhorados, atributos físico-químicos. PHYSICAL AND CHEMICAL CHARACTERIZATION OF BANANAS PRODUCED IN CONVENTIONAL AND ORGANIC CULTIVATION SYSTEMSABSTRACT -The demand for organic fruit grows every year around the world and banana can show growth in this sector both in the domestic and in the foreigner market. However, there is a lack of information that supports the production of organic fruit and that confirms the advantages and disadvantages of the cropping systems. Thus, the purpose of this study was to evaluate bananas from conventional tillage and organic relation to physical aspects. It was used Caipira (AAA), Maravilha (AAAB), Pacovan Ken (AAAB), Prata Anã (AAB), Thap Maeo (AAB) and Tropical (AAAB) cultivars. Organic farming was used in green roof (Canavalia ensiformis and Arachis pintoi) and fertilization with organic compost, rock phosphate, castor bean and wood ashes. In conventional farming it was not used green cover, proceeding only the chemical fertilization with urea (100 kg ha -1 ), simple superphosphate (280 kg ha -1 ) and potassium chloride (540 kg ha -1 ).It was evaluate the physical attributes, number of fruit per bunch, diameter (cm) and fruit length (cm), shell thickness (mm) and chemical attributes, total soluble solids ...

Fusarium wilt (syn= Panama disease), caused by Fusarium oxysporum f. sp. cubense (FOC), is one of the most destructive diseases of banana, being genetic resistance the main management strategy for this disease. Since the pathogen is constantly evolving to supplant the genetic resistance, new sources of resistance must be investigated by genetic improvement programs aiming to developing new varieties. The objective of the present study was to identify sources of resistance from the different accessions maintained in the banana active germplasm bank (BAGB) at Embrapa Mandioca e Fruticultura. Forty-one BAGB accessions were evaluated, including 17 diploids, 21 triploids, and two tetraploids. The area under the disease progress curve, disease index, and incubation period were also evaluated. In relation to FOC resistance, there is genetic variability available among the BAGB accessions. The genotype M53 is notable for the complete resistance it expressed, and the accessions Birmanie, PA Songkla, Pirua, Imperial, Poyo, Ambei, Walebo, and Kongo FRF 1286 expressed quantitative resistance.

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RESUMO -A bananicultura apresenta importância social na geração de emprego e renda e como fonte alimentar para pessoas em todo o mundo. A crescente demanda por frutos de alta qualidade tem contribuído para a conversão de áreas manejadas convencionalmente para sistemas de manejo orgânico. Contudo, inexistem informações seguras referentes às vantagens de cada tipo de manejo, que possam subsidiar os agricultores nessa importante tomada de decisão. Assim, com o objetivo de comparar cultivares de bananeira, em manejo convencional e orgânico, foram avaliadas as características agronômicas e o estado nutricional das bananeiras, quantificando-se o teor de minerais nas folhas. Foram avaliadas as cultivares Caipira (AAA), Maravilha (AAAB), Pacovan Ken (AAAB), Prata-Anã (AAB), Thap Maeo (AAB) e Tropical (AAAB). Os dados foram submetidos à análise de variância, e as médias, comparadas pelos testes Scott Knott e Tukey, a 5% de probabilidade de erro. O sistema de cultivo afetou os parâmetros agronômicos de bananeira, destacando-se a cultivar Thap Maeo, que apresentou superioridade para algumas características agronômicas, podendo ser facilmente utilizado em sistema orgânico de cultivo. As cultivares apresentaram diferenças agronômicas, independentemente do sistema de manejo adotado. O tipo de manejo afeta a maioria das variáveis, exceto para peso do cacho, peso total da penca, número de frutos por penca, despencamento e firmeza do fruto com casca. Termos para indexação: Musa spp., sistema de manejo, produtividade, caracteres agronômicos. EVALUATION OF BANANA CULTIVARS IN CONVENTIONAL AND ORGANIC CROP SYSTEMABSTRACT -The banana has social importance in generating employment and income and as a food source for people around the world. However, the growing demand for high quality fruits have contributed to the conversion of conventionally managed areas for organic management systems. However, there is no reliable information concerning the advantages of each type of management. Thus, with the goal of improved banana cultivars compared to conventional and organic agronomic traits were evaluated cultivar Caipira (AAA), Maravilha (AAAB), Ken Pacovan (AAAB), Prata Anã (AAB), Thap Maeo (AAB) and Tropical (AAAB) grown in the two systems. In addition to agronomic traits, it was assessed the production and productivity and nutritional status of banana, quantifying the concentration of minerals in samples taken from the third leaf. Data were subjected to analysis of variance and means were compared by the Scott Knott test and Tukey test at 5% probability. The cropping system affects the agronomic parameters of banana, especially the cultivar Thap Maeo that had good agronomic characteristics and can be easily used in organic system. Agronomic cultivars differ, independent of the management system adopted.