Genetic diversity in sugarcane cultivars assesed by DNA markers and morphological traits.

PERERA, M. F.; ARIAS, M. E.; COSTILLA, D.; LUQUE, C.; GARCÍA, M. B., CUENYA, M. I.; FILIPPONE, M. P. Y CASTAGNARO, A. P.

Workshop; 10th Germplasm and Breeding and 7th Molecular Biology Workshop. ISSCT; 2011

Knowledge of sugarcane genetic diversity should provide useful information concerning genotype value for breeding programs and should contribute to the improved use and conservation of genetic resources, especially since this crop should be considered as a high genetic complexity model. For the aforementioned reasons and also for protecting new sugarcane varieties and intellectual property rights, varietal identification is essential. Ideally, the identification method should be rapid, simple and inexpensive. Morphological descriptors are traditional tools to characterize varieties; however, sometimes they do not yield clear data due to ambiguous differences or phenotypic modifications caused by environmental factors. Molecular markers are becoming important for genotype identification and diversity estimation, because they are accurate, abundant and not affected by the environment. The aim of this work is to evaluate integrally the genotypes most widely used as parents by the Breeding Program of Estación Experimental Agroindustrial Obispo Colombres (EEAOC) (Tucumán, Argentina) by using different molecular techniques jointly (AFLP, SSR and ISSR), studying morphological traits and comparing data analysis softwares. All cultivars were grouped in one main cluster in dendrograms with both NTSys and InfoStat programs. At least 150 data should be included in the analysis to obtain the same cluster with both programs. Local genotypes grouped together with USA varieties: no clear genetic differentiation could be found comparing these programs, due to constant germplasm exchange. Although morphological traits only reflected external resemblance, the dendogram topology that revealed genetic relationships was not modified when molecular and morphological methods were used jointly. Therefore, both methods should be used together to estimate diversity, and molecular traits should be included in the characters established internationally for sugarcane variety protection.