Data/hora: 12/06/2024 14:39:23

Provedor de dados: | 63
País: | Brazil
Título: | Root phosphatase activity, plant growth and phosphorus accumulation of maize genotypes
Autores: | Machado,Cynthia Torres de Toledo; Furlani,Ângela Maria Cangiani.
Data: | 2004-04-01
Ano: | 2004
Palavras-chave: | Zea mays L.; Genetic variability; Enzymatic activity; Nutritional efficiency.
Resumo: | The activity of the enzyme phosphatase (P-ase) is a physiological characteristic related to plant efficiency in relation to P acquisition and utilization, and is genetically variable. As part of a study on maize genotype characterization in relation to phosphorus (P) uptake and utilization efficiency, two experiments were set up to measure phosphatase (P-ase) activity in intact roots of six local and improved maize varieties and two sub-populations. Plants were grown at one P level in nutrient solution (4 mg L-1) and the P-ase activity assay was run using 17-day-old plants for varieties and 24-day-old plants for subpopulations. Shoot and root dry matter yields and P concentrations and contents in plant parts were determined, as well as P-efficiency indexes. Root P-ase activity differed among varieties, and highest enzimatic activities were observed in two local varieties -'Catetão' and 'Caiano' -and three improved varieties -'Sol da Manhã', 'Nitrodente' and 'BR 106'. 'Carioca', a local variety, had the lowest activity. Between subpopulations, 'ND2', with low yielding and poorly P-efficient plants, presented higher root P-ase activity as compared to 'ND10', high yielding and highly P-efficient plants. In general, subpopulations presented lower P-ase activities as compared to varieties. Positive and/or negative correlations were obtained between P-ase activity and P-efficiency characteristics, specific for the genotypes, not allowing inference on a general and clear association between root-secreted phosphatase and dry matter production or P acquisition. Genotypic variability must be known and considered before using P-ase activity as an indicator of P nutritional status, or P tolerance, adaptation and efficiency under low P conditions.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162004000200015
Editor: | São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
Relação: | 10.1590/S0103-90162004000200015
Formato: | text/html
Fonte: | Scientia Agricola  v.61 n.2 2004
Fonte: | info:eu-repo/semantics/openAccess