Germination responses to temperature and water potential as affected by seed oil composition in sunflower

GONZALEZ BELO, RAUL; TOGNETTI, J.; BENECH-ARNOLD, R; IZQUIERDO NATALIA

Industrial Crops and Products

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2014 vol. 62 p. 537 - 544

0926-6690

Sunflower genotypes with increased concentration of stearic and oleic acids have been developed to ful-fil industrial specific requirements. Fatty acid composition of membranes has been widely described toaffect seed germination, but the effect of composition of reserve lipids on germination is still unknown.Two experiments were conducted including: traditional (high linoleic), high stearic?high oleic, highstearic?high linoleic and high oleic genotypes. Thermal and hydrotime analyses were performed on ger-mination data obtained from the incubation of seeds at different temperatures and water potentials. Fattyacid composition affected the parameters values of thermal time model. Base temperature was inverselyrelated to linoleic acid concentration. Genotypes with high linoleic acid concentration germinated earlierat low temperatures, while no significant differences among genotypes at temperatures above 15◦C werefound. High stearic?high oleic genotypes showed lower thermal time requirement for 50% germinationthan traditional and high stearic?high linoleic genotypes. The parameters of hydrotime model were notaffected by fatty acid composition, but at low water potentials and high temperatures thermo-dormancywas induced and strongly reduced final seed germination in all genotypes studied. In conclusion, breedingfor higher oleic acid and lower linoleic acid concentration in sunflower oil may affect seed germinationperformance at low temperatures.