Phenotypic evaluation of a diversity panel selected from the world collection of sugarcane (Saccharum spp) and related grasses

Long-term improvement of sugarcane and energy cane (complex hybrids of Saccharum spp) cultivars can be enhanced by breeding with the type of diverse germplasm available at the World Collection of Sugarcane and Related Grasses (WCSRG) maintained in Miami, Florida. To evaluate germplasm in the WCSRG for breeding pur- poses, a diversity panel was selected with approximately 300 accessions and planted at Canal Point, FL in three replications. These accessions were measured for stalk height and stalk number multiple times throughout the plant-crop growing season and for Brix and fresh biomass during the 2013 harvest. First-ratoon stalk height, stalk number, stalk diameter, internode length, Brix, and fresh and dry biomass were evaluated in 2014. The highest correlations were found between early season measurements and harvest traits. Hybrids had higher fresh weight and Brix while Saccharum spontaneum had higher stalk number and dry mass. According to the principal component analysis, the diversity panel was divided into two groups. One group had accessions with high stalk number and high dry biomass like S. spontaneum and the other had accessions with higher Brix and fresh biomass such as S. officinarum. In first ratoon, there were 110 accessions not significantly different in Brix from the sugarcane commercial standards, including 10 S. spontaneum accessions, and 17 and six accessions that were higher than commercial standards in dry and fresh mass, respectively. This study shows the variability in traits of interest and the breeding potential of accessions within the WCSRG for sugar-and energy-cane cultivar development.