Yellow Leaf Disease Resistance and Preference in Commercial Sugarcane Cultivars.

Sugarcane yellow leaf disease (YLD) caused by sugarcane yellow leaf virus (ScYLV) is a major threat for the sugarcane industry worldwide, and the aphid is its main vector. Breeding programs in Brazil have provided cultivars with intermediate resistance to ScYLV, whereas the incidence of ScYLV has been underestimated partly due to the complexity of YLD symptom expression and identification. Here, we evaluated YLD symptoms in a field assay using eight sugarcane genotypes comprising six well-established commercial high-sucrose cultivars, one biomass yield cultivar, and a susceptible reference under greenhouse conditions, along with estimation of virus titer through RT-qPCR from leaf samples.

Sugarcane mosaic virus mediated changes in cytosine methylation pattern and differentially transcribed fragments in resistance-contrasting sugarcane genotypes.

Sugarcane mosaic virus (SCMV) is the causal agent of sugarcane mosaic disease (SMD) in Brazil; it is mainly controlled by using resistant cultivars. Studies on the changes in sugarcane transcriptome provided the first insights about the molecular basis underlying the genetic resistance to SMD; nonetheless, epigenetic modifications such as cytosine methylation is also informative, considering its roles in gene expression regulation. In our previous study, differentially transcribed fragments (DTFs) were obtained using cDNA-amplified fragment length polymorphism by comparing mock- and SCMV-inoculated plants from two sugarcane cultivars with contrasting responses to SMD.

Epigenetic diversity of spp. accessions assessed by methylation-sensitive amplification polymorphism (MSAP).

The epigenetic diversity of six genotype groups (commercial cultivars, , , , , and sp.) was assessed through methylation-sensitive amplification polymorphism (MSAP). A total of 1341 MSAP loci were analyzed, of which 1117 (83.

Reference genes for gene expression studies targeting sugarcane infected with Sugarcane mosaic virus (SCMV).

Objective: The selection of reference genes in sugarcane under Sugarcane mosaic virus (SCMV) infection has not been reported and is indispensable to get reliable reverse transcription quantitative PCR (RT-qPCR) results for validation of transcriptome analysis. In this regard, seven potential reference genes were tested by RT-qPCR and ranked according to their stability using BestKeeper, NormFinder and GeNorm algorithms, and RefFinder WEB-based software in an experiment performed with samples from two sugarcane cultivars contrasting for SCMV resistance, when mechanically inoculated with a severe SCMV strain and using mock inoculated plant controls.

Results: The genes Uridylate kinase (UK) and Ubiquitin-conjugating enzyme 18 (UBC18) were the most stable according to GeNorm algorithm and the Pearson correlation coefficients with the BestKeeper index.