Sugarcane (Saccharum Spp.) produces 80% of the world's sugar along with other by‐products. The production of sugarcane is vulnerable to infestation of sugarcane yellow leaf virus (SCYLV) worldwide. A study was conducted using an F₁ segregating population derived from CP95‐1039 × CP88‐1762 to identify the genetic factors underlying SCYLV resistance. The disease infection data were measured using tissue blot immunoassay after 6 years of exposure to the virus under natural field conditions. Genetic maps were created using genotyping by sequencing‐based markers for each parent separately following a pseudo‐testcross approach. Two quantitative trait loci (QTL) were detected for SCYLV resistance accounting for 28% of the phenotypic variation. A major QTL qSCYLR79 located on linkage group 79 and linked with marker 3PAV3154 appears to be unique for SCYLV resistance in sugarcane. Progeny having a combination of two major alleles had 31% less SCYLV incidence than progeny with a combination of major and minor alleles in the genomic region of qSCYLR79. Thus, selection against the minor allele may decrease the SCYLV incidence in sugarcane.

Genomic selection (GS) has been demonstrated to enhance the selection process in breeding programs. The objectives of this study were to experimentally evaluate different GS methods in sugarcane hybrids and to determine the prospect of GS in future breeding approaches. Using sugar and yield-related trait data from 432 sugarcane clones and 10,435 single nucleotide polymorphisms (SNPs), a study was conducted using seven different GS models. While fivefold cross-validated prediction accuracy differed by trait and by crop cycle, there were only small differences in prediction accuracy among the different models. Prediction accuracy was on average 0.20 across all traits and crop cycles for all tested models. Utilizing a trait-assisted GS model, we could effectively predict the fivefold cross-validated genomic estimated breeding value of ratoon crops using both SNPs and trait values from the plant cane crop. We found that the plateau of prediction accuracy could be achieved with 4000 to 5000 SNPs. Prediction accuracy did not decline with decreasing size of the training population until it was reduced below 60% (259) to 80% (346) of the original number of clones. Our findings suggest that GS is possibly a new direction for improving sugar and yield-related traits in sugarcane.

The selection of sugarcane genotypes with high sucrose content and good ratooning ability (RA) is an important objective of the Canal Point breeding program to improve the current profitability levels of the Florida sugarcane industry. In this study, thirteen test sugarcane genotypes and three checks were evaluated in three sand locations, Pahokee Produce Inc. (PP), Townsite farm (TS), and Lykes Brothers Inc. (PF), during three crop cycles (plant cane, first ratoon, and second ratoon). Multi-environment best linear unbiased predictors (BLUPs) were highly significant for commercially recoverable sucrose (CRS) and not significant for cane yield (CY) among genotypes. The ANOVA based on the RA values produced significant genotypic effects but a reduced RA diversity among the genotypes. The simultaneous selection for BLUP_CRS, BLUP_CY yield, and RA identified CP 14-4165 and CP 13-2340 as the most outstanding genotypes. The BLUP_GGE biplots method showed that the PP location was the most discriminative for BLUP_CY, whereas the TS was the ideal location. For BLUP_CRS, the three locations had similar abilities to discriminate genotypes and were positively and strongly correlated. The which-won-where graph indicated that CP 13-2340 showed the highest BLUP_CRS levels in TS and PP locations, while CP 14-4165 and CP 14-4588 were the top genotypes in the PF location. The results suggest that selecting genotypes with high CRS values is possible without compromising the genotype discrimination for CY. CP 14-4165 and CP 13-2340 are resistant to most diseases and genetically diverse.

‘CP 13‐4100’ (Reg. no. CV‐202, PI 698546) sugarcane cultivar (a complex hybrid of Saccharum spp.) was developed through cooperative research conducted by the USDA‐ARS, the University of Florida, and the Florida Sugar Cane League, Inc. The Florida Sugarcane Variety Committee (FSVC) released CP 13‐4100 in June 2020 to growers for commercial cultivation on mineral (sand) soils. It originated from a polycross made at Canal Point (CP) on 3 Dec. 2008 where CP 96‐1252 was the female parent and the male parent was unknown and could be any one of genotypes used in the polycross. CP 13‐4100 was released by FSVC for its high cane and sucrose yields, acceptable commercial recoverable sucrose, and resistances to orange rust, leaf scald, Sugarcane mosaic virus strain E (mosaic), and smut, and acceptable levels of susceptibility to brown rust. CP 13‐4100 and commercial reference checks (i.e., CL 88‐4730, CP 96‐1252, CPCL 97‐2730) yield data were collected from 12 harvests (i.e. three crop cycles—plant cane, first, and second ratoon—at four sand‐soil locations) in final‐stage replicated yield trials. Compared with CL 88‐4730 and CPCL 97‐2730, CP 13‐4100 had significantly (P ≤ .0001) higher cane yield (tonnes of cane per hectare: 18.7 and 29.5%), sucrose yield (tonnes of sugar per hectare: 26.3 and 30.7%), and economic index (EI; 10.9–16.9%) and no significant differences from CP 96‐1252 in these traits. CP 13‐4100 tested negative for the Bru1 marker, which is linked to a quantitative major locus of brown rust resistance. CP 13‐4100 could be considered moderately tolerant to freezing among 23 tested genotypes.