Thesis
In situ imaging of root system architecture to improve drought tolerance and yield in spring wheat (Triticum aestivum L.)
Washington State University
Master of Science (MS), Washington State University
2017
Handle:
https://hdl.handle.net/2376/102063
Abstract
Drought is a predominant abiotic constraint to successful wheat production worldwide. The understanding of root system architecture is an untapped source for crop improvement since roots are instrumental for the uptake of water and essential nutrients in addition to their phenotypic plasticity to respond to heterogeneous soil conditions. Breeding for improved root traits is challenging due to the difficulties of root phenotyping in opaque soil, limited understanding of root systems in relevant crops, and laborious and time-consuming field-based studies. However, significant strides in yield enhancement have been gained through the modification of root architectural traits in corn and rice. Our studies sought to uncover spatiotemporal root growth dynamics of both young and mature root systems in six spring wheat cultivars in climate-controlled laboratory and greenhouse environments. The use of the in situ minirhizotron technique for observing the root systems in this study has provided deeper insight into the complex root growth patterns in wheat throughout the lifecycle. We were able to detect quantifiable differences in root traits in both 5-day old as well as adult root systems at heading stage across wheat cultivars tested. Further, the positive correlation of the observed root traits with grain yield and consistency in root traits observed using minirhizotrons as well as manual root extraction of young and mature root systems has reinforced the experimental results. We found that spring wheat cultivars--AUS28451, Dharwar Dry and Alpowa display superior shoot as well as root attributes at different growth stages under multiple growth conditions, which have potential for improved root traits in native dryland farming systems. The results from this study will drive future research to assess the heritability of root traits across varying environments as well as identify drought-adaptive root phenes in natural settings. Above all, the beneficial root traits identified in this study can be leveraged for either direct screening of the breeding lines through ideotype breeding or identifying the genetic makeup of root traits through molecular and quantitative genetics to breed drought-resilient wheat cultivars targeted to Pacific Northwest dryland farming communities.
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Details
- Title
- In situ imaging of root system architecture to improve drought tolerance and yield in spring wheat (Triticum aestivum L.)
- Creators
- Bikash Ghimire
- Contributors
- Karen A. Sanguinet (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Crop and Soil Sciences, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525084601842
- Language
- English
- Resource Type
- Thesis