Assessment of susceptibility of olive cultivars to theBactrocera oleae(Gmelin, 1790) andCamarosporium dalmaticum(Thüm.) Zachos & Tzav.-Klon. attacks in Calabria (Southern Italy)

Abstract

Within the framework of research concerning the application of techniques alternative to chemical pesticides for control of parasites, the C.R.A. Experimental Institute for Olive Growing for many years has been performing a large investigation in order to detect sources of genetic resistance in olive germplasm. In the present study we observed the behavior related to the olive fly (Bactrocera oleae) infestation and Camarosporium dalmaticum infection of ten olive cultivars farmed under the same agronomic and climatic conditions in Calabria, Southern Italy. The sampling and the data collecting were carried out in three different ripening times. The drupe amount of oleuropein and cyanidine was detected by laboratory analyses in order to verify a possible correlation between these molecules and the level of infestation/infection of the above-mentioned parasites. The obtained data were submitted to analysis of variance. In relation to the fungal infection the results displayed that cvs Tonda nera dolce showed the lowest susceptibility, while the cv Giarraffa turned out to be the most susceptible. The less susceptible cultivars to the phytophagous were Tonda nera dolce and Bhardi Tirana. Since the less susceptible cultivar to olive fly attacks are the same observed in relation to the susceptibility to olive fruit rot, it is suggested a relation between the olive fly infestation and the fungal infection. It suggests the utility to achieve these results both to transfer directly to the farmers' world and to emphasize ecosystem health and biodiversity conservation.

Identification of leaf volatiles from olive (Olea europaea) and their possible role in the ovipositional preferences of olive fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae)

“…Bactrocera oleae (Rossi) (Diptera: Tephritidae), the olive fly, is considered the key pest in several regions in the world, particularly in the Mediterranean area (Daane and Jonhson, 2010), causing important economic and quality losses (Malheiro et al, 2015a). The female of this dipteran shows cultivar preference by attacking specific olive cultivars (Burrack and Zalom, 2008;Iannotta et al, 2007;Navrozidis et al, 2007;Gonçalves et al, 2012). Host selection for oviposition is believed to be based on chemical (Imperato et al, 2012;Kombargi et al, 1998;Spadafora et al, 2008), physical (Neuenschwander et al, 1985;Rizzo et al, 2012), and molecular aspects .…”

Susceptibility of Cultivars to Biotic Stresses

“…Differences in the response of olive cultivars to olive fly infestations have been observed (Gümusay et al, 1990;Iannotta et al, 1999Iannotta et al, , 2006aIannotta et al, , 2007aIannotta et al, , 2007bPereira et al, 2004;Basile et al, 2006;Rizzo and Caleca, 2006;Daane and Johnson, 2010). Two phenolic compounds, oleuropein and cyanidine, were assessed to determine their role in the reduced susceptibility of certain olive cultivars to olive fly (Iannotta et al, 2006a(Iannotta et al, , 2007a(Iannotta et al, , 2007b.…”

“…The study proves the utility of further investigations in order to characterize the different cultivars behaviour in relation to their parasites, so as to define their specific susceptibility. Trials performed by Iannotta et al (2007a) in the collection field of the CRA OLI compared susceptibility to Camarosporium dalmaticum of cultivars planted in the same environmental and agronomic conditions (Fig. 2).…”

“…The susceptibility to B. oleae of other ten cultivars has been investigated by Iannotta et al (2007a). Observations were carried out detecting the percentages of sterile oviposition stings, active infestation (presence of pre-imago stages: eggs, larvae and pupae) and total infestation (emergence holes, feeding tunnels and pre-imago stages) on olive fruit samples, 200 drupes per cultivar.…”

“…Two phenolic compounds, oleuropein and cyanidine, were assessed to determine their role in the reduced susceptibility of certain olive cultivars to olive fly (Iannotta et al, 2006a(Iannotta et al, , 2007a(Iannotta et al, , 2007b. In addition, a positive correlation has been observed between the drupe oleuropein content and a low susceptibility of olive cultivars to olive fly damage such that when the drupe oleuropein content is high, the olive fruit is less susceptible to attack (Iannotta et al, 2006a(Iannotta et al, , 2007a(Iannotta et al, , 2007b. Iannotta et al (2001) investigated the huge olive showing a low susceptibility to olive fly infestations of some cultivars due to the high content of oleuropein within drupes.…”