ABSTRATThe electrical conductivity test has been used to evaluate seed vigour in many species, especially legumes, such as peas, beans and soybeans. The objective of this research was to evaluate the effect of temperature and storage period on the results of the electrical conductivity test and the mineral composition of the imbibition solution of bean seeds (Phaseolus vulgaris L.). Three seed lots of the cultivar IAPAR -81 and cultivar IPR -TIZIU were stored at 10, 25 and 25-10º C (six months at 10º C and six months at 25º C) The following evaluations were made every three months for a year: seed water content, germination and vigour (accelerated ageing and electrical conductivity) and the potassium, calcium and magnesium contents of the imbibition solution. The cultivars showed similar behavior in storage. The reduction in the vigour of bean seeds stored at 10º C was verified by accelerated ageing and electrical conductivity tests. The bean seed storage at low temperature (10º C) does not influence the results of the evaluation of seed vigour by electrical conductivity test and the quantification of calcium, magnesium and potassium ions. The evaluation of vigour by the electrical conductivity test is not recommended for bean seed stored by long periods (above 9 months). Index terms:Phaseolus vulgaris L, vigour, leaching, low temperature. RESUMOO teste de condutividade elétrica tem sido usado para avaliar o vigor de sementes de muitas espécies, especialmente de fabáceas, como ervilha, feijão e soja. Assim, nesta pesquisa, objetivou-se avaliar o efeito da temperatura e do período de armazenamento sobre os resultados do teste de condutividade elétrica e da composição mineral da solução de embebição de sementes de feijão (Phaseolus vulgaris L.). Foram utilizados três lotes do cultivar IAPAR -81 (grupo "Carioca") e três do cultivar IPR -TIZIU (grupo "Preto") armazenados a 10, 25 e 25-10º C (seis meses a 10º C e seis meses a 25º C). Ao longo de 12 meses de armazenamento, a cada três meses foram determinados: teor de água, germinação e vigor (envelhecimento acelerado e condutividade elétrica) e conteúdo de potássio, cálcio e magnésio da solução de embebição. As sementes das cultivares apresentaram comportamento semelhante no armazenamento. A redução no vigor das sementes de feijão armazenadas a 10º C foi verificada pelos resultados dos testes de envelhecimento acelerado e de condutividade elétrica. O armazenamento de semente de feijão em baixa temperatura (10º C) não influencia os resultados da avaliação do seu vigor pelo teste condutividade elétrica e a quantificação de cálcio, magnésio e potássio. A avaliação do vigor pelo teste de condutividade elétrica não é recomendada para semente de feijão armazenada por longos períodos (acima de 9 meses). Termos para indexação:Phaseolus vulgaris L, vigor, lixiviação, baixa temperatura.

Jatropha belonging to Euphorbiaceae family has around 170 species distributed throughout tropical semi-arid regions of Africa and the Americas. Some of its species include Jatropha curcas L. (Physic Nut), Jatropha pohliana Müll.Arg. (Brazilian Purging Nut) and Jatropha gossypiifolia L. (Black Physic Nut). Phenotypic and genetic studies of a population are important for plant improvements, helping in the characterization of accesses, as well as facilitating selection of parental for directed crossings.Thus, the present study aimed to evaluate accesses of three Jatropha species from different regions of Brazil, through morphological characters and ISSR molecular markers, in order to group them according to the existing degree of divergence. A higher interspecific variability, rather than intraspecific, was observed among accesses, for morphological as well as molecular characters. Qualitative and quantitative characters showed variability between accesses and may serve as reference for future genetic studies. There was no relation between similarity patterns and geographical origin of accesses in the group analysis. Average percentage of polymorphism found for inter-simple sequence repeat (ISSR) markers between the studied accesses was 40.6%. A higher genetic variability interspecific was observed than intraspecific, suggesting the search for genetic variability among species Jatropha through interspecific crosses.