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Erianthus arundinaceus [Retzius] Jeswiet, a wild relative of sugarcane has a high biomass production potential and a reservoir of many genes for superior agronomic traits and tolerance to biotic and abiotic stresses. A comparative physiological, anatomical and root transcriptome analysis were carried out to identify the salt-responsive genes and metabolic pathways associated with salt-tolerant E. arundinaceus genotype IND99-907 and salinity-sensitive sugarcane genotype Co 97010. IND99-907 recorded growth of young leaves, higher proline content, higher relative water content, intact root anatomical structures and lower Na+/K+, Ca2+/K+ and Mg2+/K+ ratio as compared to the sugarcane genotype Co 97010. We have generated four de novo transcriptome assemblies between stressed and control root samples of IND99-907 and Co 97010. A total of 649 and 501 differentially expressed genes (FDR<0.01) were identified from the stressed and control libraries of IND99-907 and Co 97010 respectively. Genes and pathways related to early stress-responsive signal transduction, hormone signalling, cytoskeleton organization, cellular membrane stabilization, plasma membrane-bound calcium and proton transport, sodium extrusion, secondary metabolite biosynthesis, cellular transporters related to plasma membrane-bound trafficking, nucleobase transporter, clathrin-mediated endocytosis were highly enriched in IND99-907. Whereas in Co 97010, genes related to late stress-responsive signal transduction, electron transport system, senescence, protein degradation and programmed cell death, transport-related genes associated with cellular respiration and mitochondrial respiratory chain, vesicular trafficking, nitrate transporter and fewer secondary metabolite biosynthetic genes were highly enriched. A total of 27 pathways, 24 biological processes, three molecular functions and one cellular component were significantly enriched (FDR≤ 0.05) in IND99-907 as compared to 20 pathways, two biological processes without any significant molecular function and cellular components in Co 97010, indicates the unique and distinct expression pattern of genes and metabolic pathways in both genotypes. The genomic resources developed from this study is useful for sugarcane crop improvement through development of genic SSR markers and genetic engineering approaches. [ABSTRACT FROM AUTHOR]

Genomic constitution of commercially cultivated sugarcane varieties over the world is derived from few basic species clones of Saccharum complex. In order to impart new cytoplasmic and nuclear genome in sugarcane hybrids, untapped wild species of Saccharum spontaneum (S), Erianthus arundinaceus (E) and E. bengalense (Eb) were utilized to produce different combinations i.e., E. arundinaceus x S. spontaneum (ES), S. spontaneum x E. arundinaceus (SE) and S. spontaneum x E. bengalense (SEb) intergeneric hybrids (H). Subsequently, these resulting hybrids were repeatedly used as pistil parent and crossed with commercial sugarcane varieties as pollen parent for three (G) to four (G) generations to produce an array of advanced generation hybrids. Twenty six such advanced generation hybrids (G and G) derived were evaluated for quality and yield contributing traits at 300 and 360 days after planting during 2010-2011 and 11-12 in augmented block design along with standard sugarcane varieties. The presence of E. arundinaceus cytoplasmic DNA was validated in intergeneric hybrids by PCR-RFLP of the amplified chloroplast DNA for psbC- trnS. Performance of ESH G and SEH G hybrids were comparable and some E. arundinaceus cytoplasm introgressed hybrids performed on par with standard varieties for yield and quality traits. Few intergeneric hybrids exhibited wider acclimatization in diverse agro-climatic conditions. Some of these intergeneric hybrids have potential for commercial cultivation and their utilization in breeding programme could help in broadening the genetic base and also for wider adaptability of future sugarcane varieties. [ABSTRACT FROM AUTHOR]