The aim of the present study was to develop a reliable reference database to discriminate between the major Greek olive (Olea europaea L.) cultivars and reveal their genetic relationships, since Greece is considered a secondary center of diversity. In order to establish genetic relationships among the 26 Greek and eight international cultivars, four amplified fragment length polymorphism (AFLP) primer pairs, 12 randomly amplified polymorphic DNA (RAPD) primers, along with measurements from 10 morphological traits, were used. A total of 576 AFLP and 113 RAPD markers were produced. Genetic similarities, estimated using the Jaccard algorithim, ranged from 0.45 to 0.83 for the AFLP data and 0.27 to 0.87 for the RAPD data. The cophenetic correlation coefficients between the genetic similarities and the unweighted pair group method of arithmetic averages (UPGMA) phenograms were 0.77 for the AFLPs, 0.81 for the RAPDs, and 0.69 for the morphological traits. However, limited clustering similarities among the phenograms derived from the three methods were observed. This was also reflected by the low correlation between the three genetic similarity matrices produced (AFLP and RAPD, r = 0.39; AFLP and morphological traits, r = 0.11; RAPD and morphological traits, r = 0.02). According to the molecular results, olive cultivars are clustered according to fruit size but not according to geographical origin. Three of the cultivars tested, `Vasilicada,' `Throumbolia', and `Lianolia Kerkiras', were found to branch distantly to the others, according to the AFLP results, and can be considered as ancient Greek cultivars.
Marianna Hagidimitriou, Andreas Katsiotis, George Menexes, Constantinos Pontikis, and Michael Loukas
Eleni Tsantili, Miltiadis V. Christopoulos, Constantinos A. Pontikis, Pantousis Kaltsikes, Chariklia Kallianou, and Michalis Komaitis
The effect of three preharvest sprays with water or 58.5 mm calcium chloride (CaCl2) on texture and other quality attributes was investigated in ‘Konservolia’ olives harvested at the black-ripe stage and measured after 1 and 15 days of storage in air at 10 °C with 85% relative humidity. Effects on fruit calcium (Ca) and magnesium (Mg) concentrations during the period of spray applications were also studied. Concentrations of Ca, Mg, and chlorophyll and photosynthesis rate in leaves were measured on the day of final fruit harvest. No foliar or fruit toxicity was observed. In leaves, Ca sprays increased Mg but did not affect Ca and chlorophyll concentration and photosynthesis rate. In fruits, Ca sprays prevented the gradual decrease in Ca concentration that occurred in untreated fruits and maintained Mg at constant levels during ripening on the tree but did not affect fruit size and oil content as measured 1 day after storage. Ca-treated fruits were firmer with lower soluble pectin (SP) concentration and higher calcium pectate (CaP) than controls in both storage days, whereas the protopectin levels were similar in all fruits. Results showed positive linear correlation between Ca concentration and either firmness or CaP, whereas that between Ca and SP was negative as found in fruits stored for 1 day. Fruit production rates of carbon dioxide and ethylene, L* and chroma (C*) of peel, and hue angle (h°) of flesh were unaffected either by Ca treatment or storage time. Ca treatment did not affect fruit weight loss, the decreases in peel h° and flesh L*, but increased flesh C* during storage. The results indicate positive effects of preharvest calcium sprays on olive firmness without any negative effect on fruits or leaves.