- A webinar organized by the Gocitrus project concludes that this technology is benefiting all links in the citrus plant industry and will soon do the same for other crops
- A pilot test of an APP with all updated varietal and agronomic information is presented to help citrus growers find the best variety-rootstock combination
- The first mandarin to use markers as the basis for its varietal certification system has been Tang Gold (Tango), from Eurosemillas. Gocitrus will facilitate the expansion of this technology: in 2021 it will obtain the differential DNA sequence of more than 25% of mandarins and 10% of oranges
The term PCR, which is now commonly used and refers to the most reliable diagnostic method for detecting Covid-19, is based on the same technology that is transforming the world of horticultural exploitation of citrus varieties. Indeed, molecular markers can serve both to define the genetic sequence of a specific coronavirus (or any pathogen) and to provide the specific genetic traits of a variety. “Molecular markers are not the future, they are already the present,” said Francisco Llatser, the former director for decades of AVASA (Horticultural Growers Association, S.A., whose member nurseries account for around 80% of Spanish plant production). His contribution “against variety piracy is having and will have an immeasurable economic impact,” he added immediately after. Llatser was quite emphatic during a webinar organized by the Gocitrus project, which also served to demonstrate how this technological revolution is benefiting all links in this chain: it is accelerating variety improvement processes, technology is beginning to be introduced to reduce the time and tests needed to obtain registration (the ‘patent’ of a variety), has perfected the control of nursery production, and is being emergently used in varietal certification and identification systems to prevent fraud.
The meeting, followed online by hundreds of people linked to the citrus sector, was doubly supported by the Ministry of Agriculture. On one side, Alfredo Pollán, head of the Innovation and Digitization Service, introduced the event, and on the other, José Antonio Sobrino, director of the Spanish Office of Plant Varieties, gave the first presentation. Sobrino detailed how the registration process for a new variety is conducted. Initially, and aside from other bureaucratic procedures, the new plant material must demonstrate that it is distinct, homogeneous, and stable. Until not long ago, these studies were based exclusively on the analysis of differential morphological and phenotypic characteristics. In contrast to this— as Sobrino confirmed—technology using markers is also emerging, which allows for the acceleration of the process by comparing the candidate variety only with those that are genetically most similar, “rationalizing the reference collections” (which are enormous in citrus and generally in all fruit trees). The UPOV (International Union for the Protection of New Varieties of Plants)—of which the EU is a member, as are most developed countries—actually has a working group (the ‘IMODDUS’) to incorporate these methods, to generate databases (specific sequences), and protocols into the registration processes.
From a legal perspective, as clarified by the specialized lawyer in obtaining law and director of AM Legal Group, Maribel Montero, variety markers are increasingly used tools in courts, both in judicial and party evidence, in processes related to variety piracy cases. “Their implementation for the unequivocal identification of varieties in citrus has a fundamental deterrent value because we no longer rely solely on expert reports based on the study of morphological characteristics, which are more complex analyses and subject to interpretation,” she warned. Alongside this, in line with what was previously mentioned by Sobrino, Montero expressed support for greater integration of these methods in registration processes. “The genetic identification of plant varieties, in a globalized market, is already starting to provide security and progress to the various economic agents in the citrus sector, but it could also do so for all botanical species,” she concluded.
Llatser, on behalf of the nursery sector and as also highlighted earlier by the representative of the Ministry of Agriculture, emphasized the “great advancement” that the incorporation of this technology into the controls of production and commercialization of plant reproduction materials by the autonomous communities has brought. “They allow, for example, to prevent the illegal multiplication of protected varieties that can be sold under another name,” he clarified. He also wanted to discuss how they have impacted improvement processes and provided examples: “The development of selection markers by IVIA to detect sensitivity to the fungus Alternaria has allowed for the elimination of hundreds of possible parent varieties to hybridize and has accelerated the improvement process of mandarins.”
The first successful case of how the use of these unique genetic sequences can also be key in the exploitation of a variety has occurred with the Tang Gold citrus (known as Tango). To testify to this, Gocitrus invited José Pellicer, director of Development at Eurosemillas, who exploits this tangerine and whose company is one of the partners in the project. Pellicer detailed the role that patented molecular markers play for Tang Gold in what is perhaps one of the most comprehensive varietal certification systems: leaf samples are taken from the fields of licensed farmers; from fruits in the warehouses of operators registered in the system; fruits are also acquired from supermarkets where the tangerine is sold throughout Europe, even – in exceptional cases – samples can be taken at Customs. All of these are sent, respecting the chain of custody by an independent company, to a specialized third-party laboratory that conducts the marker tests and in this way, by following the traceability of the tangerine, possible infractions are controlled (for example, selling labeled as other varieties, Tang Gold tangerines without the breeder’s permission).
Next, the director of the Valencian Institute of Agricultural Research (IVIA), Rodolfo Canet, intervened, whose center also participates in Gocitrus. Canet agreed that this technology “is the future even though it is already part of the present.” The new director wanted, in this regard, to limit the work of his entity to “acting as generators of knowledge” but dismissed – as has been speculated at some point – that IVIA could establish itself as a reference entity “to certify, verify or resolve disputes (over varieties) because these tasks should develop from the generation of an auxiliary sector.”
Test the APP and generate markers
“Today, making the right choice of a variety and the most suitable rootstock is a very complicated decision,” began Carlos Baixauli, director of the Cajamar Foundation’s Experience Center, who is also a partner in the project. Immediately afterwards, Baixauli demonstrated the simple operation of the first app that will assist citrus growers in this process. The application contains information from the varietal sheets of IVIA and a harvesting calendar that groups them according to whether they are ultra-early, early, medium-season, late, or ultra-late. It also integrates a history of prices, average climatic data from the last years of the nearest season, and allows the user to specify if their plot is particularly prone to frost. It will send alerts to the user if there are nearby hybrid mandarin varieties that could encourage cross-pollination and the presence of seeds in the fruit, due to the location of their land. And, as important as the choice of variety, the application will also assist in selecting the rootstock that best adapts to the climatic conditions of the plot, the characteristics of the soil (water salinity, lime, water stress), or will propose updated alternatives with rootstocks that are resistant or tolerant to certain viruses or fungal diseases.
This is the second objective of Gocitrus. The first, which is very close to being achieved, is to provide molecular markers for up to 25% of the commercially available mandarin varieties today (more than 300) and for 10% of oranges, including all of the most commercially demanded ones.