Assessment of Genetic Diversity in Contrasting Sugarcane Varieties Using Inter-Simple Sequence Repeat (ISSR) Markers

Abstract

Sugarcane is an important tropical crop, responsible for two thirds of the world sugar production, gaining actually importance as a source of biofuel. Drought tolerance is a very important feature considering the actual climate change scenario throughout the world. This study aimed to determine the genetic diversity between sugarcane varieties with contrasting features under drought. For this purpose, twelve ISSR primers were used to characterize nine sugarcane varieties under cultivation in different countries including selected drought resistant material from Northeast Brazil and two varieties from India as contrasting genotypes. 317 scorable bands were generated, among which 301 comprised polymorphic markers, with an average of 25 polymorphic bands per primer. In the generated dendrogram the accessions were placed in clusters, where cluster A included two varieties from India (Co331 and Co419), and B comprised plants eight Brazilian accessions and a 'Barbado' variety. Within this clade, drought tolerant and susceptible varieties were clearly separated. The present evaluation revealed important contrasting parental candidates regarding their drought response, very promising for future mapping approaches aiming the identification of quantitative trait loci (QTLs) associated to drought in sugarcane. The selected primers were used for the first time in sugarcane, representing valuable tools for future evaluations, with emphasis to diversity characterization and genetic mapping.