Plant architecture of Paspalum vaginatum schwartz modified by nitrate and ammonium nutrition

Pesquisa Agropecuária Brasileira

José Beltrano¹  Marta Guillermina Ronco¹  Roberto Barreiro¹  Edgardo Raúl Montaldi¹ 

[1] ,Instituto de Fisiología Vegetal (INFIVE) UNLP La Plata,Argentina

关键词: nitrogen source;    orthogravitropism;    diagravitropism;    sucrose;    fonte de nitrogênio;    ortogravitrópico;    diagravitrópico;    sucrose;   

DOI  :  10.1590/S0100-204X1999000700007

来源: SciELO

【 摘 要 】

Paspalum vaginatum Schwartz plants were grown under greenhouse conditions in a continuous-flow hydroponic culture, containing NO3- or NH4+or NH4NO3 as nitrogen source. After 30 days, the size of aerial biomass and root system decreased significantly when plants were supplied with NH4+as exclusive nitrogen source. Compared to NO3- treatment, reducing and non-reducing sugars were decreasing together with a significant increase in amino acids content. NH4+-nutrition caused tillers to grow toward an orthogravitropic position (average angle of 68° with respect to the horizontal), and with NO3--nutrition, tillers tended to become diagravitropic (average angle of 23°). With NH4NO3 all the parameters measured had values in between those of the other two sources. Thus, the morphologic differences among plants growing in NO3- or NH4+ nutrition confirm the hypothesis that nitrogen source determines the growth habit of tillers in P. vaginatum by modulating the endogenous levels of reducing-non-reducing sugars.

【 授权许可】

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