Genetic diversity in sugarcane cultivars assessed by DNA markers and morphological traits

Abstract

Better knowledge of sugarcane genetic diversity will provide useful information concerning genotypic value for breeding programs and should help to improve the use and conservation of genetic resources and the protection of sugarcane varieties by intellectual property rights. Morphological descriptors are traditional tools to characterise varieties; however, they vary phenotypically because of environmental effects. Therefore, molecular markers have become increasingly important for identifying genotypes and estimating diversity, as they are accurate, readily available, and are not affected by the environment. The aim of this research was to evaluate genotypes used as parental materials in the Sugarcane Breeding Program of Estación Experimental Agroindustrial Obispo Colombres (EEAOC), Argentina, by using molecular markers (AFLP and SSR) and morphological traits, and by comparing the data obtained with two statistical software programs (NTSys and InfoStat). All cultivars grouped in one main cluster of the dendrogram when using both programs and at least 150 data points. Local Argentine genotypes grouped together with US-varieties and no clear genetic differentiation was found, probably due to regular germplasm exchange. Although morphological traits reflected external resemblance only, the topology of the dendrogram was not modified when combining both molecular and morphological data. These results suggest that both characterisation methods should be used to estimate genetic diversity. Molecular markers should be included internationally for sugarcane variety protection.

Keywords

• programa de mejoramiento
• banco de germoplasma de caña de azúcar
• marcadores moleculares
• descriptores morfológicos