Identifying QTLs for Fiber Content and Agronomic Characters in Sugarcane Using AFLP Markers

Abstract

Sugarcane is a highly complex poly-aneuploid, heterozygous, interspecific polyploid and cultivars commonly have over 100 chromosomes. The population of 168 progenies from a cross between a sugarcane commercial variety (K 93-207) and a S. spontaneum clone (MPT 97-1) were evaluated in a replicated field trial. Stalk diameter and tillering were recorded at harvesting and subsequently plant material was evaluated for fiber content. Clones were significantly different (P<0.01) for all traits analyzed. A total of 180 AFLP simplex markers were used to analyze the inheritance of quantitative trait loci (QTLs) for stalk diameter, tillering and fiber content. Thirty putative QTLs from the simplex markers were identified for these three traits. Each QTL explained from 3.7 to 10.7% of the variation for stalk diameter and 3.7 to 9.9% for fiber content. For tillering each QTL explained from 4-8% of the variation. K 93-207 contributed a positive effect to the QTLs for stalk diameter and a negative effect for the QTLs for fiber content and tillering. MPT 97-1 contributed a negative effect to the QTLs for stalk diameter and a positive effect for fiber content and tillering. Ten of the QTLs from both parents were identified as contributing to more than one trait. However, these markers were not available for all parts of this very highly complex genome. Further work will be needed to identify more markers in this population.