Current knowledge on plant/canopy architectural traits that reduce the expression and development of epidemics

The architecture of a plant depends on the nature and relative arrangement of each of its parts; it is, at any given time, the expression of an equilibrium between endogenous growth processes and exogenous constraints exerted by the environment. The aim of architectural analysis is, by means of observation and sometimes experimentation, to identify and understand these endogenous processes and to separate them from the plasticity of their expression resulting from external influences. Using the identification of several morphological criteria and considering the plant as a whole, from germination to death, architectural analysis is essentially a detailed, multilevel, comprehensive and dynamic approach to plant development. Despite their recent origin, architectural concepts and analysis methods provide a powerful tool for studying plant form and ontogeny. Completed by precise morphological observations and appropriated quantitative methods of analysis, recent researches in this field have greatly increased our understanding of plant structure and development and have led to the establishment of a real conceptual and methodological framework for plant form and structure analysis and representation. This paper is a summarized update of current knowledge on plant architecture and morphology; its implication and possible role in various aspects of modern plant biology is also discussed.

Despite a huge population increase since the 1960s, the green revolution more than doubled world grain production and averted large-scale famine. Food crop productivity will have to be further raised, however, because the world population is still increasing rapidly. Among several parameters associated with the increase in yield potential, genes that control plant height and tiller number (in cereal crops) have recently been identified. In addition, a promising strategy to generate semi-dwarf varieties has been developed. Recent advances in plant genome analyses and plant biotechnology will realize a second green revolution through the genetic engineering of food crops.