摘要:This study was conducted to investigate the correlation and dynamics of carbohydrate content over diurnal photoperiodic cycle and sucrose-phosphate synthase activity, amylase and invertase in leaves isogenics at EE genes short day and photoperiodically neutral lines of soybean in view of paces of development over different duration period of the day. In short-day photoperiodic cycle disposition of dynamics of sugar and starch content over a day-light period, their runoff over a moon-light period and also activity of enzymes of photoperiodically neutral lines change similar to it of short-day lines. At short day neutral lines more intensively accumulate monosugar and sucrose. At long day, amylose is accumulated in content of starch comparing to short-day lines. Runoff tenseness over night period of short-day photoperiodic cycle in both groups is higher than over the same period of long-day cycle. Capability of photoperiodically neutral lines to change disposition of carbohydrate exchange over a short-day period similar to its disposition of short-day lines is one of the considerable factors in favor of the fact that under the given conditions process of growth and development, this is provided with sufficient amount of substance and energy. As a result morphogenetic processes run at the same speed over both short-day and long-day periods. It allows photoperiodically neutral lines to transit to blooming at the same term over different duration period of the day.