Genome-Wide Association Mapping of quantitative traits in a breeding population of sugarcane

RACEDO, J., GUTIERREZ, L., PERERA, M.F., OSTENGO, S., PARDO, E.M., CUENYA, M.I., WELIN, B. AND CASTAGNARO, A.P..

Workshop; 8th Molecular Biology Workshop ISSCT (International Society of Sugar Cane Technologist; 2015

The aim of this study was to establish an appropriate genome-wideassociation (GWA) analysis to detect molecular markers associated with highbiomass and sugar yield in order to be able to improve productivity insugarcane. Clones of a local breeding population were evaluated for cane yield(CY) and sugar content (SC) at two contrasting locations during three successivecrop cycles and genotyped with molecular markers (DArT and TRAP). GWA mappingwas applied within a mixed-model framework considering the possible populationstructure by using Principal Component Analysis to minimize spuriousassociations. Markers significantly associated with CY and SC in plant-cane, ratoon-1and ratoon-2, respectively, were detected and their corresponding positions inthe sorghum genome were determined. The high gene microlinearity betweensorghum and sugarcane was confirmed since sequences of sugarcane DArT markersshowed high similitude and e-value with coding sequences of Sorghum bicolor.Interestingly, sequences of DArT marker associated with trait of interest werealigned in sorghum chromosomal regions where QTLs[L1]  has been previously reported. The methodology presented in this work that combinesexisting phenotypic trial data and genotypic marker characterizations within a LinkageDisequilibrium (LD) approach including population structure as covariates has provento be highly efficient to find molecular markers associated with the measuredtraits. Therefore, GWA mapping could be a valuable tool in order to assist varietyimprovement to help supply future sugarcane demand thathas been projected for the upcoming decades. [L1]Que tipo de QTL?