Differentiation of Urochloa brizantha cultivars by inter-simple sequence repeat (ISSR) markers in seed samples

Abstract

Approximately 80-90% of cultivated grassland areas in Brazil are covered by Urochloa brizantha [syn. Brachiaria brizantha (Hochst. ex A. Rich.) Stapf.]. Some genotypes of Urochloa have being widely used with a wrong nomenclature, like species and cultivars. In this way, the Urochloa cultivar identification is primordial for breeding programs and seed production. Considering the importance of genetic purity in commercialized seed lots, the present work aimed to evaluate the use of inter-simple sequence repeat (ISSR) markers in six cultivars of U. brizantha (Xaraés; Piatã; Basilisk; MG4; MG5 and Marandu) to discriminate and determine the contamination in seed batches. Results showed that it is possible to discriminate all cultivar with only two primers in pure samples. Basilisk was confirmed as a U. brizantha cultivar. ISSR markers showed a low polymorphism level. It was not possible to separate samples intentionally contaminated even at 5%.