Monumental Trees of Cyprus Represent Attempt to Create Elite Cultivar

Researchers speculate that early olive growers had grafted native centennial trees with others imported from Greece and Lebanon to selectively breed for desirable traits.

Holy Ancient orthodox Christian church of Aaint, Agia Paraskevi, at mountain village of Askas in Cyprus
By Daniel Dawson
Mar. 1, 2018 14:36 UTC
582
Holy Ancient orthodox Christian church of Aaint, Agia Paraskevi, at mountain village of Askas in Cyprus

A recent study of mon­u­men­tal olive trees in Cyprus has shed light on a some­times cal­cu­lated, but always com­pli­cated agri­cul­tural his­tory.

Based on the data of the cur­rent study it is safe to for­mu­late the con­clu­sion that ole­i­cul­ture in Cyprus has a com­plex his­tory,” Nikolaos Nikoloudakis of Cyprus University of Technology wrote.

The rich­ness in genetic resources is prob­a­bly the out­come of the early domes­ti­ca­tion of olive trees in Cyprus that occurred in antiq­uity- Nikolaos Nikoloudakis, Cyprus University of Technology

It is pos­si­ble that hybridiza­tion between local and or for­eign mate­r­ial, fol­lowed by the selec­tion of elite geno­types has repeat­edly occurred in dif­fer­ent eras with the goal of ame­lio­rat­ing the exist­ing geno­types.”

Researchers from Cyprus University of Technology and Agricultural University of Athens found a diverse amount of genetic mate­r­ial among these iconic olive trees. Since these trees range from hun­dreds to thou­sands of years old, the researchers see the preser­va­tion of this gene pool as immensely impor­tant for the future of olive trees.

These are trees that have with­stood exten­sive and severe biotic and abi­otic adver­si­ties; hence con­sti­tute a valu­able and unex­ploited genetic pool,” said Andreas Katsiotis also of Cyprus University of Technology.

The researchers used gov­ern­ment records and field stud­ies to iden­tify and sam­ple 52 trees across north­ern Cyprus. They took DNA sam­ples from the leaves of each of the trees and com­pared them with a bench­mark of 20 known Greek cul­ti­vars.

The researchers sus­pect that the orig­i­nal olive grow­ers were try­ing to cre­ate an elite cul­ti­var of olive trees using an agri­cul­tural tech­nique known as graft­ing, which involves com­bin­ing parts of two or more plants so they grow together as one.

Much to their sur­prise, they dis­cov­ered that two-thirds of the mon­u­men­tal olive trees that were sam­pled had been grafted.

This find­ing led researchers to spec­u­late that early olive grow­ers had grafted the orig­i­nal cen­ten­nial trees with oth­ers imported from Greece and Lebanon in order to selec­tively breed for desir­able traits. Eventually, the prac­tice ceased and these grafted trees started to repro­duce nat­u­rally.

The rich­ness in genetic resources is prob­a­bly the out­come of the early domes­ti­ca­tion of olive trees in Cyprus that occurred in antiq­uity, while genetic vari­abil­ity accu­mu­lated through time,” Nikoloudakis wrote. Hence, these entries [sam­ples] rep­re­sent an unex­ploited gene pool.”

Grafting was pre­vi­ously thought to be a tech­nique that had been used for hun­dreds of years. However, these find­ings are proof that it may have been used thou­sands of years ago as an orga­nized and exten­sive pro­ce­dure.

As a result of the graft­ing all the genetic diver­sity within the pop­u­la­tion could be traced back to only a por­tion of the cen­ten­nial trees.

This was a rev­e­la­tion since selec­tion of elite cul­ti­vars since antiq­uity is evi­dent. As a result, the mod­ern Cypriot vari­eties resulted from an assort­ment of a few ancient elite clones,” Katsiotis said. Furthermore, this means that there is still a lot of genetic diver­sity out there’ to be uti­lized in order to pro­duce adapted vari­eties with high supe­rior attrib­utes.”

The genetic diver­sity that is out there” could be used to breed trees that yield more olives as well as are more resis­tant to dis­ease and adverse cli­matic con­di­tions, if the cor­rect genes are found within the pop­u­la­tion.

Elite cul­ti­vars are bet­ter than oth­ers in major agro­nomic traits includ­ing resis­tance of biotic and abi­otic stresses and high yield poten­tial,” said Young-Chan Cho of the National Institute of Crop Science in Japan.

Among these traits, Cho sug­gested that breed­ing elite cul­ti­vars may also be use­ful for resist­ing insects. The olive fruit fly is the main car­rier of the olive tree-killing dis­ease, Xylella fas­tidiosa. Cyprus is among the eight European Union nations most con­cerned about the dis­ease, but has not suf­fered major out­breaks such as those seen in Spain, Italy and France.

Katsiotis said that a large pool of genetic diver­sity is the pre­req­ui­site for breed­ing these elite cul­ti­vars. However, more research would need to take place in order to deter­mine whether those traits exist in the Cypriot gene pool.

Surely these geno­types are well adapted in the dry east­ern Mediterranean cli­mate, but we can­not be cer­tain if they will exhibit sig­nif­i­cant resis­tance to exotic pathogens with­out fur­ther exper­i­men­ta­tion,” he said.





Advertisement
Advertisement

Related Articles