EFFECT OF SEED WATER CONTENT DURING STRATIFICATION ON DORMANCY RELEASE IN Polygonum aviculare L. SEEDS.

CRISTIAN MALAVERT; DIEGO BATLLA; ROBERTO LUIS BENECH-ARNOLD

Buenos Aires

Congreso; XXII Congreso de la ALAM - I Congreso de la ASACIM; 2015

ASACIM - FAUBA- AACREA - UCA

p { margin-bottom: 0.25cm; direction: ltr; color: rgb(0, 0, 0); line-height: 120%; }p.western { font-family: "Liberation Serif","Times New Roman",serif; font-size: 12pt; }p.cjk { font-family: "Droid Sans Fallback","Times New Roman"; font-size: 12pt; }p.ctl { font-family: "FreeSans","Times New Roman"; font-size: 12pt; }a.western:link { }a.ctl:link { }Changesin the level of dormancy in the seed bank are exposed to differentstimuli from several environmental factors simultaneously. The mainregulatory factor is temperature, but it is not known exactly howthis effect is modulated by the seed hydration level determined bysoil water content. The aim of this work was to study the effect ofwater content during stratification period on dormancy release ratein P.aviculareseeds. Tomeasurethe effect of water content, seeds of P.avicularewere stored at 5 °C during 100 days (thermal stratificationconditions for dormancy release) under controlled conditions ofrelative humidity (%RH)of 5%RH(ZnCl2),15 %RH(LiCl),61 %RH(Ca(NO3)2),75 %RH(NaCl), 88 %RH(KCl), 96 %RH(KNO3),100%RH(H2O)and imbibed seeds; under these conditions moisture content values inthe seeds of 6.7, 7.6, 11.4, 13.4, 15.8, 22, 29.8 and 35.1%were obtained respectively. Results obtained showed the existence ofa lower water content threshold of 15 % in the seed below which nodormancy release takes place. Seed water content values above thisthreshold promoted the effect of stratification temperature ondormancy release, showingan increase in the dormancy loss rate with increasing seed watercontents, reaching aplateauabove 29.8 %.The resultsobtained in this study are among the first to quantify the effect ofseed moisture content during the stratification period on thedormancy release rate. These results could be incorporated intoexisting predictive models to take into account the effect of soilwater content on the dormancy loss process. p { margin-bottom: 0.25cm; direction: ltr; color: rgb(0, 0, 0); line-height: 120%; }p.western { font-family: "Liberation Serif","Times New Roman",serif; font-size: 12pt; }p.cjk { font-family: "Droid Sans Fallback","Times New Roman"; font-size: 12pt; }p.ctl { font-family: "FreeSans","Times New Roman"; font-size: 12pt; }a.western:link { }a.ctl:link { }