Identifying loci controlling fiber composition in polyploid sugarcane (Saccharum spp.) through genome-wide association study

Authors: YANG, XIPING - University Of Florida; Todd, James; ARUNDALE, REBECCA - Bp Biofuels North America, Llc; BINDER, JOSEPH - Bp Biofuels North America, Llc; LUO, ZILIANG - University Of Florida; Islam, Md; Sood, Sushma; WANG, JIANPING - University Of Florida

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/12/2019
Publication Date: 1/17/2019
Citation: Yang, X., Todd, J.R., Arundale, R., Binder, J., Luo, Z., Islam, M.S., Sood, S.G., Wang, J. 2019. Identifying loci controlling fiber composition in polyploid sugarcane (Saccharum spp.) through genome-wide association study. Industrial Crops and Products. 130:598-605. https://doi.org/10.1016/j.indcrop.2019.01.023.
DOI: https://doi.org/10.1016/j.indcrop.2019.01.023

Interpretive Summary: Because fossil fuels are unsustainable, there is a need for alternative energy sources. Bioenergy feedstocks, which are derived from renewable living organisms such as plants and algea, are one of these sources. Sugarcane is an important feedstock that accountf for 60% of the bio-ethanol production globally. Different components of the cell wall affect bio-ethanol conversion. To aid in breeding for 12 cell wall fiber components, the fiber composition of plants collected from a diverse panel of the World Collection of Sugarcane and Related Grasses were evaluated for molecular markers associated with fiber components. The markers will assist breeders as they seek to make selections that affect the cell wall composition.

Technical Abstract: The energy crisis of the 1970s spurred the exploration of renewable energy. As an energy-efficient C4 plant, sugarcane (Saccharum spp.) is one of the most important feedstocks for bio-ethanol production, contributing approximately 60% bio-ethanol globally. The plant cell wall mainly consists of cellulose, hemicellulose and lignin. Different fiber components of the cell wall could greatly affect conversion of lignocellulose to bio-ethanol. Therefore, the evaluation of fiber composition and dissection of underling loci in sugarcane are critical for breeding sugarcane cultivars for bio-ethanol production. In this study, we evaluated 12 fiber components of cell wall in a sugarcane diversity panel consisting of 308 accessions in three replicates. We further conducted a genome-wide association study between the traits evaluated and high-density DNA markers with dosages and gene actions taken into consideration. In total, 106 non-redundant markers and 107 candidate genes were identified to be significantly associated with 10 of the fiber components evaluated. This is the first investigation of molecular factors controlling the fiber composition of the cell wall in sugarcane. This study provides a large number of novel genomic resources for selecting/modifying fiber composition in sugarcane simultaneously to improve bio-ethanol production. Moreover, our study suggests that introduction of diverse or wide germplasm in breeding programs to enhance other sugarcane traits did not change sugarcane lignocellulose quality for bio-ethanol production.