Phenotypic characterization of the Miami World Collection of sugarcane (Saccharum spp.) and related grasses for selecting a representative core

Abstract

The Saccharum L. genus includes important crops that are utilized for sugar and fuel production. The World Collection of Sugarcane and Related Grasses (World Collection) in Miami, FL contains diverse and potentially useful germplasm for this and related genera; however, this collection has been underutilized because little is known about the traits of its accessions. Our objectives were to phenotypically characterize the World Collection and select a representative core collection that could then be studied intensively. In total, eight morphological traits of the World Collection were evaluated three times in 1 year. A core of 300 accessions that included each species in the World Collection was selected by using the Maximization Strategy in MStrat software. The core had a higher diversity rating than random selections of 300 accessions. The Shannon–Weaver Diversity Index scores of the core and whole collection were similar indicating that the majority of the diversity was captured by the core collection. The ranges and medians between the core and World Collection were similar; only two of the trait medians were not significant at P = 0.05 using the non-parametric Wilcoxon method and the coincidence rate (CR % = 96.2) was high (>80) indicating that extreme values were retained. Thus, the phenotypic diversity of these traits in the World Collection was well represented by the core collection. Agronomic studies on the core should be useful for characterizing the World Collection and genes for useful traits should be available in the core collection.