Abstract

S4-07

QTL Mapping in an F₁ Population from Non-inbred Parents in Cassava (Manihot esculenta): Yield and Root Quality Traits

Okogbenin E.^1,2 and Fregene M.¹

1.        International Center for Tropical Agriculture, AA6713, Cali, Colombia    m.fregene@cgiar.org

A F₁ population intra-specific cross obtained from non-inbred parents was evaluated in replicated multi-locational trials for dry root yield (DRY), dry matter content (DMC), fresh root yield (FRY), number of storage roots (NSR), and fresh shoot weight (FSW) over a period of two years.  Other traits evaluated were harvest index (HI), leaf area index (LAI), starch content (STC), starch yield (STY), amylose content (AML), culinary quality (CQ) and post harvest deterioration (PHD).  Molecular markers for QTL analysis was from male- and female- derived linkage maps previously constructed based on 135 and 143 markers respectively.  Analysis of variance indicates significant genetic variation in the F₁ population for most of the traits.  Many QTLs, between 4 and 11 QTLs were identified for each trait with individual effects ranging between 6% and 18%, a total of 81 QTLs were detected.  Our results revealed strong genotype x environment effect for a majority of the QTLs (91%).  The identification of QTLs controlling traits of agronomic importance provides a powerful tool for understanding the genetics of these traits of and can serve to guide breeding schemes for their improvement.