Agriculture Reference
In-Depth Information
Chapter 2
Natural Variation as a Tool to Investigate
Nutrient Use Efficiency in Plants
Giorgiana Chietera and Fabien Chardon
Abstract A huge natural variation exists between individuals within a given plant
species. Most of the responses of growth-related traits to different environmental
scenarios are genotype dependent. Hence, natural variation in plants provides an
interesting and valuable source of genetic diversity to study plant responses to
environmental factors. The identification of genes that underlie phenotypic varia-
tion has an enormous practical implication by providing a means to improve crop
yield and quality. The approach based on natural variation aims to use naturally
occurring differences to improve our knowledge about complex physiological
responses of plants to their environment, including nutrition efficiency. An over-
view of different approaches currently used in plant research aimed at dissecting
complex quantitative traits is presented here, with a special focus on those related to
Nutrient Use Efficiency, to explain strategies based on QTL mapping in segregating
populations and association mapping in wild populations. Some case studies
regarding each of the investigative strategies described are detailed.
Keywords NUE (nitrogen use efficiency) • Nitrogen • Assimilation efficiency
• Remobilization efficiency • QTL • MAGIC populations • GWAS • Nutrient
limitation • Candidate genes • Arabidopsis • Natural variation
Introduction
Plants are considered adapted to variable and sub-optimal environments when they
show the ability to successfully grow and reproduce in them. In order to deal with
changing and challenging environmental conditions, plants exhibit a wide range of
integrated responses, which usually display complex quantitative variation. Plant
adaptation interests a large community of scientists, from ecologists and molecular
geneticists working on fundamental mechanisms of adaptation, to crop breeders
looking for natural variants which could optimise environmental resources and
provide targets for breeding programs (Trontin et al.
2011
). The identification of
genes that underlie phenotypic variation can have enormous practical implications
