Testing the potential significance of different scion/rootstock genotype combinations on the ecology of old cultivated olive trees in the southeast Mediterranean area.
A previous multi-locus lineage (MLL) analysis of SSR-microsatellite data of old olive trees in the southeast Mediterranean area had shown the predominance of the Souri cultivar (MLL1) among grafted trees. The MLL analysis had also identified an MLL (MLL7) that was more common among rootstocks than other MLLs. We here present a comparison of the MLL combinations MLL1 (scion)/MLL7 (rootstock) and MLL1/MLL1 in order to investigate the possible influence of rootstock on scion phenotype.



A linear regression analysis demonstrated that the abundance of MLL1/MLL7 trees decreases and of MLL1/MLL1 trees increases along a gradient of increasing aridity. Hypothesizing that grafting on MLL7 provides an advantage under certain conditions, Akaike information criterion (AIC) model selection procedure was used to assess the influence of different environmental conditions on phenotypic characteristics of the fruits and oil of the two MLL combinations. The most parsimonious models indicated differential influences of environmental conditions on parameters of olive oil quality in trees belonging to the MLL1/MLL7 and MLL1/MLL1 combinations, but a similar influence on fruit characteristics and oil content. These results suggest that in certain environments grafting of the local Souri cultivar on MLL7 rootstocks and the MLL1/MLL1 combination result in improved oil quality. The decreasing number of MLL1/MLL7 trees along an aridity gradient suggests that use of this genotype combination in arid sites was not favoured because of sensitivity of MLL7 to drought.



Our results thus suggest that MLL1/MLL7 and MLL1/MLL1 combinations were selected by growers in traditional rain-fed cultivation under Mediterranean climate conditions in the southeast Mediterranean area.
Institute of Plant Sciences, Israel Plant Gene Bank, Agricultural Research Organization, 75359, Rishon LeZion, Israel. barazani@agri.gov.il.
Oz
0000-0002-1557-7799
O
Barazani
Institute of Plant Sciences, Israel Plant Gene Bank, Agricultural Research Organization, 75359, Rishon LeZion, Israel.
Yoni
Y
Waitz
Department of Fruit Tree Sciences, Institute of Plant Sciences, Agricultural Research Organization, Gilat Research Center, 85280, M.P. Negev 2, Israel.|Institute of Biochemistry, Food Science and Nutrition, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, 76100, Rehovot, Israel.
Yizhar
Y
Tugendhaft
Department of Geography and Environmental Development, Ben-Gurion University of the Negev, 84105, Beer-Sheva, Israel.
Michael
M
Dorman
Department of Fruit Tree Sciences, Institute of Plant Sciences, Agricultural Research Organization, Gilat Research Center, 85280, M.P. Negev 2, Israel.
Arnon
A
Dag
Arab Agronomist Association, Al Nahda St., Ramallah and Al-Bireh Governorate, 4504, Al-Bireh, Palestine.
Mohammed
M
Hamidat
Arab Agronomist Association, Al Nahda St., Ramallah and Al-Bireh Governorate, 4504, Al-Bireh, Palestine.
Thameen
T
Hijawi
Institute of Biochemistry, Food Science and Nutrition, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, 76100, Rehovot, Israel.
Zohar
Z
Kerem
Institut für Spezielle Botanik und Botanischer Garten, Johannes Gutenberg-Universität Mainz, 55099, Mainz, Germany.
Erik
E
Westberg
Institut für Spezielle Botanik und Botanischer Garten, Johannes Gutenberg-Universität Mainz, 55099, Mainz, Germany.
Joachim W
JW
Kadereit
D055864:Droughts; D004463:Ecology; D005838:Genotype; D019083:Mediterranean Region; D031658:Olea / Q000145:classification / Q000235:genetics* / Q000254:growth & development; D018517:Plant Roots / Q000145:classification / Q000235:genetics / Q000254:growth & development; D014197:Trees / Q000145:classification / Q000235:genetics* / Q000254:growth & development
Akaike information criterion (AIC) selection model; Environmental conditions; Multi-locus lineage analysis; Olive oil quality; Selection