مطالعه اثر اسموپرايمنيگ بر جوانه زني بذر چغندر در شرايط تنش خشكي

The Effect of Osmopriming on Germination of Sugar Beet Seeds Under The Effect of Osmopriming on Germination of Sugar Beet Seeds Under

Seed priming is a technique to improve seed and seedling performance. The purpose of priming is to reduce germination time and improve stand and percentage of germination. This research was counducted under laboratory conditions in the University of Tehran in 2002. In this study sugar beet seeds of two geneticaly monogerm varieties (Rasoul and 276) were selected and primed with polyethylene glycol (PEG) over various times ( 3, 5 and 7 days ). After determining the optimum water potential and time for priming, the primed and control ( unprimed ) seeds were tested under simulated drought stress using PEG solutions ( 0, -2, -4 and -6 bars). Germinated seeds were counted every 24 h. for 10 days. The numbers of normal seedlings were also detected. Results showed that the best osmotic potential for priming of sugar beet seeds was -1.2 MPa for 5 days, which increased germination up to 8% and 1% for 276 and Rasol varieties, respectively. Drought stress decreased germination percentage for both primed and non-primed seed. However, this reduction was lower for primed seeds as compared to non-primed seeds. Mean germination time (MGT) was affected by drought stress, but primed seeds reached to their 500/0 germinationin 0.7 to 1.4 days earlier.