Open Access Maydica 62-2017 Original Paper RECEIVED 01/11/2017 Phenotypic evaluation of a diversity panel selected from the world collection of sugarcane (Saccharum spp) and related grasses James Todd 1,$ , Hardev Sandhu 2 , Anna Hale 3 , Barry Glaz 4 , Jianping Wang 5 * 1 USDA-ARS Sugarcane Field Station, Canal Point FL 33438, USA 2 University of Florida, Everglades Research & Education Center, 3200 E. Palm Beach Road, Belle Glade, FL 33430-4702, USA 3 USDA, ARS Sugarcane Research Unit, 5883 USDA Road Houma LA 70360 USA 4 Retired USDA-ARS Sugarcane Field Station, Canal Point FL 33438, USA 5 Agronomy Department, Plant Molecular and Cellular Biology Program, Genetics Institute, University of Florida, Gainesville, FL 32610, USA $ Present address: USDA, ARS Sugarcane Research Unit, 5883 USDA Road Houma LA 70360 *Corresponding author: E-mail: wangjp@ufl.edu Keywords: core collection, Erianthus, Miscanthus, biofuel, bioenergy Introduction The Saccharum genus is an important source of plants for sugar and fuel production. Breeding pro- grams have not fully utilized the genetic potential of the Saccharum genus found within germplasm col- lections to enhance biomass yield and resistance to abiotic and biotic stresses. Two large germplasm col- lections called the World Collection of Sugarcane and Related Grasses (WCSRG) are located at the USDA- ARS Subtropical Horticulture Research Station in Mi- ami, FL and the Research Centre at Kannur (Kerala, India) respectively. The Miami collection contains 20 Saccharum species and approximately 1,200 acces- sions from 45 countries. The most abundant species within the collection are S. spontaneum and S. of- ficinarum, along with hybrid Saccharum genotypes. Based on molecular marker and phenotypic data, a core collection of 300 accessions and 10 checks with three replications was planted in Canal Point, FL to capture the majority of the diversity (Nayak et al, 2014; Todd et al, 2014) available in the WCSRG. Due to the labor required to maintain and evaluate Abstract 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 compo- nent 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. the entire WCSRG, this smaller diversity panel with three replicates was more practical for accurately characterizing and analyzing existing variability in the entire collection. Because many of the clones in the collection are progenitors to modern sugarcane and energy cane cultivars (Bremer, 1961; Nair, 2008; Tew and Cobill, 2008), an intensive study of this replicated panel can improve sugarcane breeders’ knowledge of the relationship between germplasm and plant phe- notypic characteristics (Upadhyaya and Ortiz, 2001). Phenotypic characterization of the panel should be useful for parental selection for both energy cane and sugarcane breeding programs, and can be used as a diversity panel for identifying QTLs for yield, disease resistance, fiber content and other important traits for use in marker assisted selection(Perera et al, 2012). The objectives of this study were to 1) phenotypi- cally characterize a representative diversity panel de- rived from the WCSRG; 2) investigate how the mea- sured phenotypic traits correlate with yield and how these correlations change at different developmental stages; 3) compare traits among species and deter- mine how ranks among species for different traits