N-partitioning, nitrate reductase and glutamine synthetase activities in two contrasting varieties of maize

Pesquisa Agropecuária Brasileira

Altair Toledo Machado²  Ladaslav Sodek¹  Mânlio Silvestre Fernandes¹ 

[1] ,Embrapa Centro Nacional de Pesquisa de Agrobiologia Seropédica RJ ,Brazil

关键词: nutrient transport;    nitrogen;    grain;    source sink relations;    plant breeding;    transporte de nutrientes;    nitrogênio;    grãos;    relação fonte-dreno;    melhoramento de plantas;   

DOI  :  10.1590/S0100-204X2001000200006

来源: SciELO

【 摘 要 】

In order to identify useful parameters for maize genetic breeding programs aiming at a more efficient use of N, two maize varieties of contrasting N efficiency, Sol da Manhã NF (efficient) and Catetão (inefficient) were compared. Experiments were carried out under field and greenhouse conditions, at low and high N levels. The parameters analysed included total and relative plant and grain N content, biomass and the activities of nitrate reductase and glutamine synthetase in different parts of the plant. It was found that the translocation efficiency of N and photoassimilates to the developing seeds and the source-sink relations were significantly different for the two varieties. N content of the whole plant and grain, cob weight and the relative ear dry weight were useful parameters for characterizing the variety Sol da Manhã NF as to its efficient use of N. Enzymes activity of glutamine synthetase (transferase reaction) and nitrate reductase did not differ among the varieties.

【 授权许可】

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