Genotypic variation in water-soluble carbohydrate accumulation in wheat
Sari A Ruuska1, Greg J Rebetzke1, Anthony F van Herwaarden2
1CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia.
Functional Plant Biology : FPB
|July 22, 2020
Summary
Breeding wheat for higher stem water-soluble carbohydrates (WSC) is feasible, as genetic differences are substantial and heritable. These WSC reserves aid grain filling, especially when photosynthesis is limited by drought.
Area of Science:
- Plant Physiology
- Agricultural Science
- Genetics
Background:
- Stem water-soluble carbohydrates (WSC) in wheat contribute to grain filling, particularly under stress.
- Limited assimilation, such as during end-of-season drought, highlights the importance of WSC reserves.
Purpose of the Study:
- To assess the potential for breeding wheat for increased stem WSC accumulation.
- To investigate genotypic and environmental influences on WSC concentration and composition.
Main Methods:
- WSC concentration was measured at anthesis across diverse wheat genotypes in multiple environments.
- WSC composition, including fructan degree of polymerization (DP), was analyzed in selected genotypes.
Main Results:
- Significant genotypic and environmental variation in stem WSC concentration was observed, with high broad-sense heritability (H = 0.90 ± 0.12).
- Variation in total WSC was primarily due to differences in fructan content, while sucrose and hexose levels varied less.
- Higher WSC accumulation correlated with increased abundance of higher DP fructo-oligosaccharides (DP > 6).
Conclusions:
- Breeding for enhanced stem WSC in wheat is a viable strategy to improve grain filling.
- Fructan biosynthesis appears to be a sequential process dependent on sucrose availability, with genotypic differences unlikely due to major mechanistic variations.
