Potentials, Challenges, and Genetic and Genomic Resources for Sugarcane Biomass Improvement

Abstract

Lignocellulosic biomass has become an emerging feedstock for second-generation bioethanol production. Sugarcane (Saccharum spp. hybrids), a very efficient perennial C4 plant with a high polyploid level and complex genome, is considered a top-notch candidate for biomass production due to its salient features viz. fast growth rate and abilities for high tillering, ratooning, and photosynthesis. Energy cane, an ideal type of sugarcane, has been bred specifically as a biomass crop. In this review, we described (1) biomass potentials of sugarcane and its underlying genetics, (2) challenges associated with biomass improvement such as large and complex genome, narrow gene pool in existing commercial cultivars, long breeding cycle, and non-synchronous flowering, (3) available genetic resources such as germplasm resources, and genomic and cell wall-related databases that facilitate biomass improvement, and (4) mining candidate genes controlling biomass in genomic databases. We extensively reviewed databases for biomass-related genes and their usefulness in biofuel generation. This review provides valuable resources for sugarcane breeders, geneticists, and broad scientific communities involved in bioenergy production.

The Impact of cDNA Normalization on Long-Read Sequencing of a Complex Transcriptome

“…Finally, sugarcane is an important industrial crop with a great potential for biofuel and biomaterial production to reduce our dependence on fossil fuel energy. Modification of sugarcane biomass can be tailored by genetic approaches for a better composition for converting to biofuels and other high value molecules (Waclawovsky et al, 2010; de Souza et al, 2014; Furtado et al, 2014; Hoang et al, 2015; Kandel et al, 2018). The sugarcane genome is complex, and this hinders the sequencing progress and understanding of the genome structure and functions, compared to progress made for other grass species including sorghum and maize in recent years (Souza et al, 2011; Thirugnanasambandam et al, 2018).…”

Evaluation of genomic selection and marker-assisted selection in Miscanthus and energycane

“…hybrids), a type of sugarcane that has been bred for use as a bioenergy feedstock, has great potential as a source of lignocellulose and/or sugar for sustainably producing biofuels (Kandel et al 2018). Nevertheless, the cultivation and productivity of energycane has been hampered by its narrow genetic base and disease susceptibility because most modern energycane varieties were derived from few interspecific hybrids between S. officinarum L. and S. spontaneum L. (Wang et al 2013). To improve disease resistance in energycane, two other genera (Miscanthus and Erianthus) that share a close phylogenetic relationship with energycane have received appreciable attention (Tew and Cobill 2008).…”

“…To improve disease resistance in energycane, two other genera (Miscanthus and Erianthus) that share a close phylogenetic relationship with energycane have received appreciable attention (Tew and Cobill 2008). For instance, intergeneric crosses between S. officinarum 'Ludashi' and Erianthus rockii have been used to introgress brown rust resistance into energycane (Wang et al 2013). Miscane, a hybrid of Saccharum × Miscanthus, has been noted to exhibit increased cold tolerance and disease resistance compared with ordinary Saccharum and therefore can potentially facilitate disease resistance introgression back into energycane through backcrossing (Chen and Lo 1989).…”

“…Markers tagging quantitative trait loci (QTL) and other genomic signals exhibiting statistically significant associations with traits have been identified in energycane (Yang et al 2018), which can potentially facilitate marker-assisted selection (MAS) in energycane breeding programs. Given the success of MAS breeding programs in other crops (Okogbenin et al 2007;Xu and Crouch 2008;Jiang 2013;Yohannes et al 2015), the potential of MAS to develop disease-resistant energycane crops is promising. Nevertheless, MAS-based breeding approaches are undermined by several factors.…”

Sugarcane as Future Bioenergy Crop: Potential Genetic and Genomic Approaches

“…Sugarcane bagasse contains 22% lignin, 24% hemicellulose, and 43% cellulose whereas sweet sorghum has 21% lignin, 27% hemicellulose, and 45% cellulose with theoretical ethanol production of 12,938 and 5,804 kg per ha respectively. Though sugarcane has higher productivity as compared with its counterparts (sweet sorghum, sugar beet) yet further improvement in its fiber and sugar contents is desired to transform it into energy cane [32].…”