|Kim, Woojae - Rural Development Administration - Korea|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/27/2018
Publication Date: 10/16/2018
Citation: Barnaby, J.Y., Kim, W., Rivers, A.R., McClung, A.M., Maul, J.E. 2018. Profiles of rhizosphere soil microbial composition affecting methane emissions. 5th International Rice Conference Abstract. Available: http://ricecongress2018.irri.org/sites/default/files/Profiles%20of%20Rhizosphere%20soil%20microbial%20composition%20affecting%20methane%20emmissions.pdf.
Technical Abstract: Agriculture is recognized as a significant contributor to greenhouse gas emissions (GHGE) globally. Methane (CH4) is an important GHG and is 25 times more potent than CO2 and is the primary GHGE from flooded rice fields, which have ideal conditions for methanogens, the anaerobic bacteria that produce methane. Because of the extensive global rice acreage, reducing CH4 emissions due to rice production would have a significant impact on global warming. Research has shown that the amount of methane emitted from paddy rice can vary by cultivar indicating that genetics has the potential for mitigating the effects of GHGE. In this study, we sought to investigate whether genetic variation in methane emissions exists and further to understand the mechanism of soil-rice-methane producing bacteria interactions. Five rice cultivars were examined to relate seasonal methane profiles with anatomical and/or physiological characteristics i.e. root and shoot biomass, tiller number, aerenchyma density, plant height, developmental stage, etc. The results showed that root biomass was a major driver that affected total methane emissions. This was verified in a subsequent study with nine recombinant inbred lines (RILs) and their parents, Francis and Rondo, segregating for methane emissions and root biomass. Moreover, next-generation sequencing was performed to characterize the predominant microbes present in the soil microbiome among those nine RILs and their parents. The profiles of seasonal CH4 emissions and root biomass were associated with the temporal profiles of rhizosphere soil microbial composition to understand the mechanisms of rice-soil-microorganisms interactions that produce methane. This study provided the fundamental information to identify/develop low CH4 emitter lines with high yield potential that will have sustainable grain production in response to changing environments.