Effect of saline and hydric stress on thegermination of Wedelia glauca (ort) Hoffman ex Hicken

SOBRERO M. T, CHAILA S, FERNÁNDEZ O, SABBATINI M R

Tafí del Valle, Tucumán

Congreso; XXV Annual Scientific Meeting Tucuman Biology Association; 2009

Asociaicón de Biología de tucumán

Biocell 32 (2), 2009. p. 140 25 EFFECT OF SALINE AND HYDRIC STRESS ON THE GERMINATION OF Wedelia glauca (Ortega) O. Hoffman ex Hicken.  Sobrero M. T., Cahila S, Fernández O. A, Sabbatini N. R Fac. de Agronomía y Agroindustrias, UNSE, Avda. Belgrano 1912, 4200 S. del Estero, E-mail: marite@unse.edu.ar Germination is a key event in success determination of weed in an agro-ecosystem. The ability to germinate under hydro stress or high saline content in soil can give advantage to a weed but not to other species. The objective of this work was to determine the effects of saline and hydro stress on the germination of Wedelia glauca. Twenty fruits were incubated in sodium chloride solutions of 0, 0.4; 0.8; 1.2; 1.6; 2.0 and 2.4 mM. Then, the germinated plantlets were weighted and root length were measured. Solutions with osmotic potentials of 0; -0.2; -0.4; -0.6; -0.8; -1.0 MPa, were made with PEG 6000 (Polyethylene glycol 6000) in water. Non-linear regression  analysis was used. W. glauca germination decreases when sodium chloride concentrations increases from 0 to 2.4 mM. Percentage was higher  (91.88%) in distilled water and decreases to 16.25% at 2.0 mM. Germination was inhibited at 2.4 mM; 50% of germination was at 1.2 mM. Under saline conditions root length and plant weight were affected. Plants do not survive under high saline soils. Germination decresed from 85% to 11.25% when hydric stress increased from 0 to -0.6MPa. Germination was completely inhibited at -0.8 MPa and higher. W. glauca ability for germinating until -0.6 MPa indicate that the weed is not sensitive to low hydric potentials and is capable of establishment in low humidity content soils.