Researchers Identify Olive Genes Associated with Fruit Weight

The findings could help growers select the most productive olive varieties. Next, they plan to look for genes associated with polyphenol production.
By Daniel Dawson
Oct. 11, 2023 14:45 UTC

Researchers in Spain have iden­ti­fied nine genes that they said showed a high sta­tis­ti­cally sig­nif­i­cant cor­re­la­tion” with fruit weight.

Historically, fruit weight was the most sig­nif­i­cant trait sought by farm­ers when iden­ti­fy­ing which wild olive cul­ti­vars to domes­ti­cate, along with oil con­tent and abil­ity to grow in anthro­pogenic envi­ron­ments.

Larger fruit size is extremely impor­tant in cul­ti­vated olive trees to facil­i­tate har­vest­ing,” researchers from the University of Jaén and the Institute of Agricultural and Fisheries Research and Training (Ifapa) wrote in the study pub­lished in Plants.

See Also:Researchers Work to Reverse Genetic Erosion, Breed Resilient Olive Varieties

Therefore, fruit size in tra­di­tional olive cul­ti­vars is much big­ger than in wild ones,” they added. However, as the long juve­nile period is a main hin­drance in clas­sic breed­ing approaches, obtain­ing genetic mark­ers to be used in breed­ing pro­grams for this trait is a highly desir­able tool.”

According to the researchers, this was the first study iden­ti­fy­ing indi­vid­ual genes linked with olive weight. The Discover Foundation, an Andalusian gov­ern­ment research sup­port group that funded the study, hailed the find­ings as a sig­nif­i­cant advance­ment in under­stand­ing the genet­ics of olive fruit devel­op­ment.

The researchers used data from the genomes of 40 cul­ti­vated olive vari­eties and ten wild olive tree species, which they had pre­vi­ously sequenced, select­ing rep­re­sen­ta­tive sam­ples of each vari­ety with olives of dif­fer­ent weights.

They said the 40 cul­ti­vated olive vari­eties rep­re­sent more than 90 per­cent of the genetic vari­abil­ity of domes­ti­cated olive tree vari­eties. They added that the ten wild vari­eties sequenced rep­re­sented a broad geo­graph­i­cal sam­ple of non-domes­ti­cated olive trees.

The researchers extracted DNA from the 50 spec­i­mens using a genome-wide asso­ci­a­tion study analy­sis, which they said was sim­i­lar to read­ing” and assem­bling DNA as if it were a detailed instruc­tion man­ual.

By doing this, they found 113 genetic mark­ers grouped into sev­eral clus­ters. The researchers then ran a sta­tis­ti­cal analy­sis to detect cor­re­la­tions between the clus­ters of genetic mark­ers and cross-ref­er­enced between the olive sam­ples.

As a result, they deter­mined that 18 of 31 mark­ers clus­tered into nine groups were linked with fruit size and weight, sug­gest­ing nine genes are involved in deter­min­ing fruit size.

Checking spe­cific genetic mark­ers, such as those that deter­mine the weight of the olive, facil­i­tates the selec­tion of trees with ben­e­fi­cial char­ac­ter­is­tics, thus speed­ing up the genetic improve­ment process,” said Francisco Luque, a researcher from the University of Jaén and co-author of the study. It is like open­ing a man­ual for each tree that tells us its qual­i­ties.”

For exam­ple, if a very young olive tree is ana­lyzed and it is con­cluded through a genetic analy­sis that the fruit will have a mediocre weight, the deci­sion could be made to dis­card it and use resources on a spec­i­men whose genetic mark­ers indi­cate that the olive will weigh more,” he added.

The researchers now plan to use a sim­i­lar method to iden­tify the genetic mark­ers and genes that influ­ence the pro­duc­tion of polyphe­nols in dif­fer­ent olive vari­eties. They believe this will help farm­ers pro­duce olives with greater organolep­tic value and health ben­e­fits.

We want to iden­tify the genes respon­si­ble for the pro­duc­tion of dif­fer­ent polyphe­nols and between dif­fer­ent vari­eties of olive trees and deter­mine why some fruits have a greater amount of these mol­e­cules than oth­ers,” Luque said.


Related Articles