ИСТИНА

STIMULATION OF GERMINABILITY OF AGED SEEDS BY VARIOUS PHYSICAL ACTIONS Biophysics Department, Lomonosov Moscow State University, Moscow, 119991, Russia, taveselova@yandex.ru Until now, it remained unclear why seeds that were stored for a long time and had lost the germinability, restores it after a weak short-term exposure to the factors of different nature. To answer this question it was necessary to understand why part of aged but living seeds did not germinate. During storage, the heterogeneity of the seed population increases. The method based on the detection of room temperature phosphorescence (RTP) of dry individual seeds allows us to estimate the changes in seed quality and population heterogeneity. This method allows to subdivide a lot of aged seeds into three fractions: strong (low RTP level), weak and dead seeds. It has been shown that during aging some strong seed (fraction I) are transformed to fraction II. This leads to a decrease in germination percentage of seed lot. A characteristic feature of the seed fraction II is twofold greater content of glucose, indicating the activation process and the non-enzymatic hydrolysis of oligosaccharides (Veselova at al., 2015). We used various seeds of low germination percentage: pea 80 and 38%, wheat 47%, barley 67%, oat 69% and cucumber 82%. To stimulate the seed germination, the following techniques were applied: -irradiation, electro-magnetic field, electric field of the corona discharge, light-impulse irradiation, laser irradiation and sound action. Measurements of RTP of seeds after any treatment showed that some fraction II seeds returned back to a fraction I. These seeds were cold "improved" because they produced normal seedlings and seed lot germination increase. A specific feature of such “improved” air-dry seeds was the reduction of glucose content in them, indicating the activation of non-enzymatic glycosylation reaction. Seed treatments causing an "improvement" of seed quality do not repair the damage accumulated during seed aging, but rather favor their further deterioration. The "improved" seeds retain their high quality from several days to weeks or months. Veselova T.V., et al., Deterioration mechanisms in air-dry pea seeds during early aging, Plant Physiology and Biochemistry (2014), http://dx.doi.org/10.1016/j.plaphy.2014.12.019. 2015