Features of adaptation of photosynthesis of winter wheat plant leaves to growing conditions

Abstract

Depending on the growing conditions, the intensity of photosynthesis of winter wheat plant leaves varies from 7.58 to 15.76 µmol CO2/m2s, significantly decreasing (on average by 41%) in dry and hot weather. During the day, its value varies from 7.07 to 12.48 µmol CO2/m2s, reaching a maximum (12.48 µmol CO2/m2s) in the morning (from 9:00 to 11:00 am), when the air temperature is not so high (from 18 to 23°C), and the light becomes saturating (1000 -1300 µmol/m2s). In the time following, the intensity of leaf photosynthesis decreases, reaching the minimum values at 7:00 pm. At the same time, the flag leaves of plants are characterized by the highest photosynthetic activity - from 12.56 to 16.16 µmol CO2/m2s, exceeding the pre-flag leaves by 1.6 times, and the lower ones by 3.1 times. The stomatal apparatus plays an important role in the adaptation of leaf photosynthesis to environmental factors. The correlation coefficient of photosynthesis intensity with stomatal conductivity in different leaf locations varied from 0.97 to 0.98.