IDENTIFICATION OF MOLECULAR MARKERS ASSOCIATED WITH FATTY ACID COMPOSITION IN PLANTS

摘要

A map was constructed from AFLP, RPLP and SSR analysis of the progeny derived from an interspecific cross involving a Colombian Elaeis oleifera (UP 1026) and a Nigerian E. guinneensis (T128). This interspecific cross was used to map genes associated with oil quality. A framework map was generated for the male parent, T128, using Joinmap ver. 3.0. In the paternal guineensis map, 389 markers (305 AFLP, 64 RFLP and 20 SSR) were ordered in 18 linkage groups (157IcM). The E. guineensis map was also used in scanning for quantitative trait loci (QTLs) controlling oil quality (measured in terms of iodine value and fatty acid composition). At a 99 % significant genomic wide threshold level, QTLs associated with iodine value (IV), C14:0, C16:0, C16:l, C18:0 and C18:l were detected. The same genomic region appears to be influencing IV, Cl 8:1 and C 16:0 content. Considering the three traits are strongly correlated further supports the data observed. The QTLs also explain a significant proportion (about 35%) of the variation observed. Similarly significant QTLs for C16:l and C14:0 were detected around the same locus in separate genomic region. This probably points to another major locus influencing fatty acid composition. Markers associated with IV and FAC (C 14:0, C16:0, C16:l and Cl 8:1) were confirmed in a second mapping population or in palms of different genotype. The markers concerned are RFLP probes, namely CB75A (for IV, C16:0, C18:l) and RD56 (for C14:0 and C16:l) and microsatellite (SSR) marker P4T8 (Cl 8:0 and C16:0).