Identification of QTLs Controlling Genes of Ripening Time, Flesh Detachment from Stone and Firmness in Olive (Olea europaea L.)

Olive fruits and olive oil have been studied for many years due to its potential health benefits. Besides providing energy, they compose of significant amounts of plant-derived anti-oxidants, phyto-sterols, vitamins and minerals. Olive is a diploid species having 46 chromosomes (2n=2x=46) and about 3.120 Mbp genome size. Olive fruit ripening, firmness, and flesh detachment from stone are the main criterias in table olive market so these traits are one of the main criterias for researches in olive breeding. Compare to other fruit crops there are few data available about the QTL analysis of some characters in olive. Parents and 92 F₁ individuals was used in this study. Ripening time was found with the mean value of 161.5 days  and 165.8 days in 2011 and 2013 respectively. Flesh detachment from stone was detected in Memecik as difficult and, as easy in Uslu in both years. The firmness of Memecik was detected 22 N and 22.7 N and Uslu was found 19 N and 15.8 N in 2011 and 2013 respectively. In the Memecik linkage map 1 QTL region identified for ripening time explaining the phenotypic variation between 10.0-16.6%, 3 QTL region and 1 putative QTL marker found for flesh detachment from stone explaining the phenotypic variation between 10.0-14.9% and 1 QTL region detected for firmness, explained the phenotypic variance with 9.5-22.0%. In the Uslu linkage map a total of 2 QTL regions were mapped for firmness, explaining the phenotypic variation between 9.8-26.6%.  Identification of these QTL regions could be useful data for molecular breeding programmes and new varieties of olive could be improved using these markers for early selection in future.