Crescimento de genótipos de gramíneas ornamentais em condições de salinidade

Abstract

Lawns performing various functions, among them is beautify public places, help to prevent soil erosion and act as protector of dust and sludge. In Brazil, the best widespread genus is the Paspalum sp, the most common Paspalum notatum kind because it presents a greater number of species native to Brazil. The salinity may be a limiting factor that may disadvantage the growth of lawns by toxicity of sodium and chloride ions. The experiment was conducted at Experimental Pacajús Field of Embrapa in Fortaleza - CE from March to June 2015. O objective was to evaluate five accessions of Paspalum species subjected to five different levels of salinity in order to select the best species. This study used five accessions of species of grass, of Paspalum gender sp.. They were submitted to different salinity doses: 0.5, 1.5, 3.0, 4.5 and 6.0 dS.m-1. The variables analyzed were related to electrical conductivity of the soil, determining the levels of Na+ and Cl- and growth variables, including the determination of the dry mass of leaves and roots, leaf area and surface of bare soil and morphological evaluation through force, fixation and staining. In the inorganic solute contents species of Paspalum sp, through the mechanism of tolerance they were able to expel the ions. For the values of dry matter leaves the best performances were achieved accesses 23 and 24 and the root dry matter only for access 24. Access control showed the highest leaf area followed by material 14, 5 and 23. The assessment morphological, high salinity doses caused the process Aof burning and yellowing, especially access and 23 own witness. According to the analyzed variables, access 24 showed better tolerance to salt stress.