Photosynthesis and Carbon Assimilation

J. Masle observed that among genotypes of wheat and barley there was a positive correlation between relative growth rate and net assimilation rate as assessed by growth analysis. In this chapter, the authors discuss modeling of photosynthesis, advances in the understanding of the biochemical regulation of photosynthesis, and progress in the understanding of the biophysical constraints on photosynthesis. They examine the relationship between photosynthesis and growth using equations in which photosynthesis is explicit, rather than implicit in terms such as radiation-use efficiency. The authors aim to emphasize mathematical treatments of photosynthesis because of the growing importance of crop modeling and because trade-offs of carbon gain and water and nutrient use are quantitative and subtle. Also, as with the studies of biochemical and biophysical regulation of photosynthesis, sometimes the relationship between leaf level photosynthesis can be obscured by plant responses.