ABSTRACT
This study evaluated 26 pigeonpea rhizobial isolates according to their cultural characteristics, intrinsic antibiotic resistance, salt and temperature tolerance, carbon source utilization and amylolytic activity. The cultural characterization showed that the majority of them presented the ability to acidify the YMA. Among the 27 isolates evaluated, 25 were able to grow when incubated at 42° C and 11 showed tolerance to 3% (w/v) of NaCl in YMA medium. The patterns of carbon sources utilization was very diverse among the isolates. It was observed the capacity of three strains to metabolize all the carbon sources evaluated and a total of 42% of the bacterial isolates was able to grow in the culture medium supplemented with at least, six carbon sources. The carbon sources mannitol (control) and sucrose were metabilized by all isolates evaluated. The profile of intrinsic resistance to antibiotics showed that the isolates were mostly resistant to streptomycin and ampicillin, but susceptible to kanamycin and chloranphenicol. High amylolytic activity of, at least, four isolates was also demonstrated, especially for isolated 47.3b, which showed the highest enzymatic index. These results indicate the metabolic versatility of the pigeonpea rhizobia, and indicates the isolate 47.3b to further studies regarding the amylase production and characterization.
Subject(s)
Anti-Bacterial Agents/analysis , Drug Resistance, Microbial , Streptomycin/isolation & purification , Genetic Variation , Nitrogen Fixation , Phenotype , Rhizobiaceae/physiology , Rhizobiaceae/isolation & purification , Biotechnology , Methodology as a SubjectABSTRACT
O objetivo deste trabalho foi avaliar algumas correlações entre as características da planta em bananeira 'Prata-Anã' grupo genômico (AAB) conduzidas de uma forma diferente da tradicional e em diferentes épocas no período de fevereiro de 2002 a janeiro de 2003. O experimento foi instalado na Fazenda Reunidas FLL Ltda em uma área cultivada com a cultura da bananeira com cinco anos de idade e plantadas no espaçamento de 3,5 m x 2,0 m, no município de Cristais Paulista SP. O delineamento estatístico utilizado foi inteiramente casualizado no esquema de parcelas subdivididas, com três repetições, sendo as parcelas constituídas pelos tipos de manejos (M1) planta-filha desenvolvida sem a planta-mãe, a qual teve o pseudocaule retirado logo após a emissão floral e (M2) planta-filha e planta-mãe desenvolvidas normalmente até a colheita de seus cachos (manejo convencional). As subparcelas foram constituídas por doze épocas de seleção da planta-filha (fev./02 a jan./03). Avaliou-se as características circunferência do pseudocaule, peso do cacho das plantas-mãe e filhas e o ciclo vegetativo da planta-filha. De acordo com as análises das variáveis avaliadas, observou-se correlação positiva entre as circunferências dos pseudacaules das plantas-mãe e plantas-filha, correlação positiva entre a circunferência do pseudocaule da planta-mãe e o peso do seu cacho, porém esta correlação não foi significativa na planta-filha, os pesos dos cachos das plantas-mãe e plantas-filha não foram correlacionados entre si, o ciclo vegetativo das plantas-filha correlacionou-se negativamente com a circunferência do pseudocaule das mesmas e os manejos nas touceiras (M1) e (M2) e as épocas de seleção da planta-filha não afetaram as correlações avaliadas neste trabalho.
The aim of this study was to evaluate the correlations between vegetative and productive characteristics of banana tree (Musa spp) cv 'Prata-Anã' (genomic group AAB) differently managed from the conventional system. The experiment was carried out in an orchard with five years old banana plants spaced by 3,5 x 2,0 m, in the Fazendas Reunidas FFL Ltda., at Cristais Paulista, São Paulo, Brazil. The experiment was a split plot under a completely randomized design with three replicates, being the main treatments constituted by: M1 - daughter-plant without the mother-plant whose stem was cut after flowering; M2 - daughter-plant and mother-plant conventionally managed until harvest. The sub plots were constituted by twelve periods of selection of the daughter-plants (February 2002 to January 2003). The pseudostem diameter and the bunch weight of all plants and the vegetative period of the daughter-plants were evaluated. The statistical analysis showed a positive correlation between the stem diameter of the daughter-plants and mother-plants. The stem diameter of the mother-plant was positive correlated with its bunch weight. However the stem diameter of the daughter-plant not was correlated with its bunch weight. The vegetative cycle and the pseudostem diameter of the daughter-plants were negatively correlated. The Plant management (M1 and M2) and the selection of periods daughter-plant did not affected the correlations evaluated in this study.