Data/hora: 10/06/2024 00:54:21

Biblioteca(s): | Embrapa Soja.
Data corrente: | 20/10/2005
Data da última atualização: | 20/10/2005
Autoria: | ANDRADE, D. S.; MATOS, M. A.; COLOZZI-FILHO, A.; HUNGRIA, M.
Título: | Diversity of rhizobial isolates from commom bean seeds in Brazil.
Ano de publicação: | 2004
Fonte/Imprenta: | In: INTERNATIONAL SYMPOSIUM ON MICROBIAL ECOLOGY, 10., 2004, Cancun. Microbial planet: sub-surface to space. Cancun: Internacional Society for Microbial, 2004. p.1131.
Idioma: | Inglês
Conteúdo: | Previous studies on the biodiversity of rhizobia associated with common bean (Phaseolus vulgaris L.) have emphasized the promiscuous nature of the host plant. Seeds of common bean can carry many viable rhizobial cells and studies performed in Mexico identified the presence of Rhizobium etli on the seeds. In this study, 103 fast-grower isolates of Phaseolus-rhizobia were obtained from 32 seed samples of several cultivars collected in the States of Parana, São Paulo and Minas Gerais, in Brazil. Thirty-eight % of those samples carried viable cells of rhizobia on the seeds that resulted in nodulation ranging from 1.5 to 45 nodules per plant. Nodule size ranged from 2 to 5 mm of diameter and nodules showed internal color white or pink. One-hundred and three isolates were morphologically characterized aiming their grouping according to the phenotypic traits and differences among them were verified on several properties. Polymerase Chain Reaction (PCR)-mediated restriction fragment length polymorphism (RFLP) analysis of the 16S-23S rRNA internally transcribed spacer (ITS) region and of the 16S rRNA gene indicated that the rhizobial subpopulation isolated from seeds of cultivar Carioca contained the largest number of ITS groups. Based on the number of ITS, the diversity and richness, estimated with the Shannon and Margalef indices, ranged from 0.69 to 2.89 and 0.45 to 6.04, respectively. The presence of infective rhizobia on common bean seeds may have contributed to the high level of rhizobial diversity observed in Brazilian soils.
Thesagro: | Bacteriologia do Solo; Feijão; Rhizobium; Semente.
Categoria do assunto: | --
Registro original: | Embrapa Soja (CNPSO)
Exemplares: | CNPSO - (25642-1) - UPC - SP - -- - 11271 -  - 11271 - DIS