THE IMPACT OF UV-B RADIATION ON THE PHOTOSYNTHESIS AND GROWTH OF PEAS (Pisum sativum L.)

The impact of 1 and 3 kJ m(-2) d(-1) UV-B radiations on peas (Pisum sativum L.) photosynthesis system and growth was investigated in this work. Peas were sown in vegetative pots with prepared neutral acidity peat substrate. Ten and seventeen days after germination, i.e. at leaf development (BBCH 14-16) stage and formation of lateral shoots (BBCH 21-23) stage pea plants were exposed to different UV-B radiation. Investigated 1 and 3 kJ m(-2) d(-1) UV-B doses decreased photosynthetic rate of BBCH 14-16 stage peas 22.3% (p > 0.05) and 76.8% (p < 0.05), and BBCH 21-23 ones - 22.9% (p > 0.05) and 56.8% (p < 0.05) respectively. 1 kJ m(-2) d(-1) UV-B close had no statistically significant impact on chlorophyll a content of all treated plants, contrary 3 kJ m(-2) d(-1) impact chlorophyll a content of BBCH 14-16 and BBCH 21-23 stages peas decreased 27.6% (p < 0.05) and 24% (p < 0.05) respectively. Both investigated UV-B doses stimulated chlorophyll b synthesis in all treated plants but statistical insignificant (p > 0.05). 1 and 3 kJ m(-2) d(-1) UV-B radiations decreased dry biomass of BBCH 14-16 stage peas 13.8% (p > 0.05) and 35.2% (p < 0.05) respectively. And dry biomass of BBCH 21-23 ones exposed to 1 and 3 kJ m(-2) d(-1) radiations decreased 19.5% (p > 0.05) and 25.2% (p > 0.05) respectively.