SciELO - Scientific Electronic Library Online

 
vol.42 issue3Anatomical changes in the leaves and roots of Jatropha curcas L. cultivated under saline stressMethods and temperatures of hydration on physiological quality of corn seeds author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Revista Ciência Agronômica

On-line version ISSN 1806-6690

Abstract

FEIJAO, Alexcyane Rodrigues et al. Effect of nitrate nutrition on tolerance of sudangrass plants to salinity. Rev. Ciênc. Agron. [online]. 2011, vol.42, n.3, pp. 675-683. ISSN 1806-6690.  http://dx.doi.org/10.1590/S1806-66902011000300014.

This work aimed to study the effect of NO3- nutrition on growth, on gas exchange and on inorganic and organic solutes accumulation of sudangrass plants subjected to salinity. Plants were grown in hydroponic medium and kept in a greenhouse. The experiment was a completely randomized design, following a factorial arrangement of 2 (NO3- at 0,5 mM or 8,0 mM) x 2 (NaCl at 0 mM or 100 mM), with five replications. All data were subjected to analysis of variance and the means were compared by Tukey's test at 5% of significance. Salinity reduced leaf area and dry weight of shoots and roots. However, plants growing in the 8.0 mM NO3- increased more than those growing in 0.5 mM. The stomatal conductance, photosynthesis, transpiration and the relationship between internal and external concentration of CO2 were increased by better nutrition NO3-. Na+ and Cl- contents were significantly increased by salinity in leaves and roots and the K+ content was reduced only in the roots. Nevertheless, plants fed with 8.0 mM NO3- had the lowest contents of Na+ and Cl- in leaves under salt stress. Salinity increased proline and amino acid contents and the higher NO3- concentration promoted the accumulation of these solutes in roots of stressed plants. Proper nutrition for NO3- was able to reduce deleterious effects of salinity in sudangrass plants.

Keywords : Growth; Salt stress; Nitrogen; Inorganic and organic solutes; Sorghum sudanense.

        · abstract in Portuguese     · text in Portuguese     · pdf in Portuguese