EFFECT OF TEMPERATURE ON THE GERMINATION

MARCHESSI J.E.; CROSTA H.N.; JUAN V.F; BENTIVEGNA D. J.; FERNÁNDEZ O.A.

BIOCELL

INST HISTOL EMBRIOL-CONICET

Año: 2011 vol. 35 p. 237 - 238

0327-9545

Euphorbia davidii is an annual weed with wide distribution in the center of Buenos Aires province which reducing yield of soybean, sunflower and corn crops (59¡Æ52¡¯52¢ªW, 36¡Æ46¡¯05¢ªS). To determine the effect of temperature on the germination were used seeds from two harvests (1995 and 2009) that were stored in laboratory conditions. Using 2,3,5 tryphenyl-tetrazolium chloride test, seed viability was 40% and 73.5% for 1995 and 2009 harvest, respectively. Both seed groups were put to germinate on tissue paper inside compartments in a thermal gradient. Temperature range was from 5.5 to 28 C with incrementing of 1.5 C in each compartment, resulting in 16 temperatures assayed. While maximum seed germination of 27.5% at 22 C for 1995 harvest, it was obtained 64% at 16 C for harvesting 2009. These values correspond to 69 and 87% of viable seeds in the harvest 1995 and 2009, respectively. The optimum temperature range for seed germination was from 11.5 to 22 C for harvesting in 1995 seeds and from 13 to 20.5 C for harvesting in 2009. Maximum germination was 17 C in both cases. Few seeds germinated below 8.5 C and above 26.5 C. E. davidii can germinate in a wide range of temperature. Determination of temperature of germination is a biological parameter used to developing integrated strategies of management.