Soybean cultivars with high photosynthetic efficiency were studied to see how they perform in terms of photosynthesis and yield. The researchers found that these cultivars had different rates of photosynthesis and dark respiration under specific light and temperature conditions. They also observed that photoinhibition occurred at high light levels among the cultivars. The cultivars with high photosynthetic efficiency were less affected by photoinhibition compared to those with high yield. Additionally, the critical temperatures for photoinhibition were higher in the high photosynthetic efficiency cultivars.