4. Extension of the characterization of varieties and certification in the IOC Network

The production of healthy and authentic olive plant material is a vitally important issue, not only for the exchange between research centres and germplasm banks, but also for the commercial transactions undertaken by the nursery industry.

To guarantee the conservation of existing olive varietal biodiversity and promote the international  certification of olive nursery plants, the International Olive Council (IOC) launched the True Healthy Olive Cultivars (THOC) project. This initiative, carried out by the University of Córdoba with the participation of the 23 germplasm banks forming the IOC Network, represents an important milestone in consolidating the IOC Germplasm Bank Network. It has provided an effective tool for the authentication of the most internationally important olive varieties, ensuring the availability of healthy and authentic plant material to facilitate certified plant production across member countries.

At present, authenticity and representativeness are not guaranteed in most olive germplasm banks. Significant confusion persists due to homonyms (the same name for different cultivars), synonyms (different names for the same cultivar) and errors in denomination (in correct names assigned to cultivars). Overcoming this confusion is a fundamental prerequisite for in any germplasm bank that precedes the evaluation of the agronomic and oleotechnical characteristics of its accessions.

Misidentification can lead to the erroneous attribution of valuable traits to the wrong accessions, or, conversely, to the same name being linked to widely differing agronomic profiles. Until recently, the universal method for varietal identification was morphological characterisation.

Even today, the registration a new varieties is legally based on morphological descriptors, as set out in the UPOV technical protocol TG/99/4 (International Union for the Protection of New Varieties of Plants). However, since the 1990s, molecular DNA markers have increasingly been used to enhance, discrimination capacity and reliability in the identification of the genotype, as they are not influenced by environmental conditions and eliminate subjectivity in identification. In particular, the combination of morphological traits with molecular markers—especially microsatellites (SSRs) —currently represents the most universal, discriminating, and accessible method in many germplasm banks.

Similarly, molecular markers associated with morphological traits (e.g., SNP-EST, SSRs-EST, etc.) are now being developed and compared with traditional methods. The advent of massive genome sequencing and its interpretation is expected to provide a universal tool, not only for varietal identification, but also for locating genes associated with agronomic and oleotechnical traits of interest, thereby accelerating the breeding of new varieties.

In 2016, the IOC endorsed the promotion ofe the authenticated and healthy plant exchange within its Germplasm Bank Network. Subsequently, in 2018, the IOC formally launched the THOC collaborative project to support the international certification of olive nursery plants by IOC member countries.

The model used for producing this material is based on the Public Repository of Commercial Olive Cultivars of Spain (University of Córdoba), where "prebasic” and “basic" category material is produced for Spanish nurseries wishing to initiate certified plant production. This process is governed by, the Technical Regulations for the Control and Certification of Fruit Tree Nursery Plants (Royal Decree 1256/2010 of 8 October, amending Royal Decree 929/1995) (Figure 1).

To this end, a new module was built to host the most internationally important commercial olive
varieties, using the same production frameworks.  

Figure 1. The Public Repository of Commercial Olive Cultivars of Spain, WOGB-UCO: production of prebasic and basic material for certified, true-to-type (authentic), healthy (pathogenfree) olive plants.
 

The production of certified olive plants is currently governed by the national regulations established by each country, as production and trade control areis carried out at the national level. Governments oversee the traceability of the entire production system different plant material categories (prebasic, basic, certified mother plants, and certified plants) produced by authorised nurseries. This process involves controlling production methods, sampling, and laboratory analysis to ensure varietal
authenticity and phytosanitary safety in accordance with national legislation.

National regulations, in turn, are based on European guidelines that harmoniseset out the common line of actions across EU member states.countries, These guidelines are described in the Commission Implementing Regulation (EU) 2019/2072 of 28 November 2019, establishing uniform conditions for the implementation of Regulation (EU) 2016/2031 of the European Parliament and the Council on, protective measures against plant pests, and repealing Commission Regulation (EC) No 690/2008 and amending Commission Implementing Regulation (EU) 2018/2019. 

Additionally, international organisations such as the European and Mediterranean Plant Protection Organization (EPPO) provide recommendations on the production of certified plants. These are prepared by experts specialising in certification, pests, and diseases, and serve as a roadmap for European guidelines and national policies.

The latest revision of the EPPO Standard PM 4/17 for olive, made in 2022, comprehensively covers the actions, plant material categories, recommended analysis techniques for disease analysis and diagnosis, and the control and production schemes for each stage of production of certified material.

Figure 2. illustratess the EPPO scheme for the production of certified material:  SCHEMES FOR THE PRODUCTION OF HEALTHY PLANTS FOR PLANTING

Figure 2. Diagram showing the stages in the olive plant certification scheme.