A genetic linkage map of olive based on amplified fragment length polymorphism, intersimple sequence repeat and simple sequence repeat markers

A detailed genomic linkage map of the olive (Olea europaea L. ssp.europaea (2x=2n= 46)) was constructed with a 147 F1 full-sib 'Olivi` · 'Arbequina' progeny in a two-way pseudo-test cross-mapping configuration. Based onalogarithmofoddsthresholdof6andamaximumrecombination fractionof0.4,maternalandpaternalmapswere constructed using 222 makers (178 amplified fragment length polymorphism (AFLP), 37 simple sequence repeat (SSR),sevenintersimplesequencerepeat(ISSR))and219markers(174AFLP,39SSR,6ISSR)markers,respectively. The female map regrouped 36 linkage groups (LGs) defining 2210.2 cM of total map length with an average marker spacing 11.2 cM and a maximum gap of 48.5 cM between adjacent markers. The male map contained 31 LGs and covered a distance of 1966.2 cM with an average and a maximum distance between two adjacent markers of 10.3 and 40.4 cM, respectively. Mean LG size was 61.3 and 63.4 cM in the maternal and paternal maps, respectively. The LGs consisted of two to 17 loci (up to 21 loci in the paternal map) and ranged in length from 2.7 to 182 cM (female map) or from4.1 to 218.1 cM(paternal map).Markers were distributed throughout the mapswithoutanyclustering. Thetotal length of the consensus map was 3823.2 cM containing 436 markers distributed into 42 LGs with a mean distance between two adjacent loci of 8.7 cM. Both parental maps and the consensus maps were compared with previously published olive maps. Although not saturated yet, the present maps offer a promising tool for quantitative trait loci mapping because phenotypic characterization of the cross is currently carried out. Olive is one of the most important Mediterranean fruit species cultivated for oil and canned fruit consumption. With over 2000 cultivars, the olive tree is highly diverse and adapted to Mediterranean agroecological conditions. It plays a major socioeconomical role in traditional agroecosystems, especially in southern Mediterranean areas with an expanding use in oil and cosmetic industries (Aburjai and Natsheh, 2003). Olive is a diploid species (2n = 46 (Green and Wickens, 1989)) with a nuclear DNA content ranging from 2.90 ± 0.020