Advancing coffee breeding and genetic conservation through tissue culture technology in Saudi Arabia
RIYADH | The Kingdom of Saudi Arabia is characterized by extremely hot and dry weather conditions with summer temperatures sometimes reaching highs of 50°C in some regions and falling close to 0°C during winter. The Kingdom also receives very low rainfall, averaging between 200 and 600 mm annually in the mountainous and coastal regions and less than 100 mm inlands. These conditions hinder sustainable agricultural production in the Kingdom. Arabica coffee (Coffea arabica L.) has been cultivated in the southwestern mountainous regions of Saudi Arabia since the 15th century. Over the years, the original coffee populations have co-evolved with the harsh climatic conditions and have undergone a combination of natural and farmers selection, resulting in elite genotypes that are better adapted to the Saudi conditions.
Analysing genetic wealth through sustainable practices
Under the ongoing Sustainable Rural Agriculture Development (SRAD) project, implemented by the Ministry of Environment, Water and Agriculture (MEWA), the genetic wealth of Saudi coffee is being analysed through morphological, phenotypic and molecular characterization of the coffee genotypes grown by the farmers. With the technical support provided by Food and Agriculture Organization of the United Nations (FAO) in collaboration with the National Seed Center, diverse genotypes with the most desirable attributes have been identified. The genetic integrity of these valuable genotypes must be conserved as the government seeks to increase the local production of Arabica coffee in Saudi Arabia, through development of the most adaptable coffee varieties. This has prompted the need for the introduction of tissue culture propagation, which involves culturing plant tissues (mainly leaves) under sterile and controlled conditions to generate disease-free seedlings (saplings) that are genetically uniform and true to type.
Tissue culture technology for long-term sustainability goals
Since its introduction in Saudi Arabia in 2022, the tissue culture technology has shown remarkable success and great potential as a mass vegetative propagation method for the selected coffee genotypes, without distorting their genetic composition, hence maintaining their inherent attributes. Through the technical support from FAO, in collaboration with Estidamah, a tissue culture protocol uniquely designed for Saudi coffee genotypes was developed, tested and optimized. So far, over 4 000 tissue culture propagated coffee seedlings have been rooted. In addition, the weaning and hardening protocol has been developed and is currently being optimized using the first batch of 80 seedlings transferred to Aseer region for evaluation of their performance under field conditions.
“This technology will aid the multiplication and conservation of native Saudi coffee genotypes against the risk of genetic contamination or extinction due to climate change challenges or diseases, thus ensuring long-term sustainability,” said Hudson Lubabali, FAO Tissue Culture Expert.
Building local capacity
The tissue culture facility has also successfully imparted hands-on technological skills to five Saudi youths (2 male and 3 female) as a means of capacity building, ensuring the sustainability and scalability of the technology. These enthusiastic youths will also gain competence skills on a recently acquired advanced technology of tissue culture bioreactors, further enhancing efficiency and supporting the upscaling of the facility’s utility.
“It was amazing to see how a seedling can emerge from a small piece of leaf and develop to a normal coffee plant. The hands-on skills I have gained in plant tissue culture technology has equipped me with the requisite capacity to apply the technology in different plant species. This has given me the confidence to embrace the technology to contribute to sustainable agriculture,” said Zaed Alanazi, Estidamah Trainee and Laboratory Assistant.
Broader opportunities in coffee sector
The success of tissue culture technology offers a myriad of opportunities in the coffee sector in Saudi Arabia. Besides its utility in micro-propagation, the technology could be utilized in coffee breeding to expand the narrow genetic base associated with Arabica coffee through designed creation of soma-clonal variation. It can also be applied in genetic engineering of coffee to introduce novel genes for disease resistance without significantly affecting the yields, quality and other inherent desirable attributes. In addition, the technology can be used to propagate F1 hybrids, thus reducing the coffee breeding cycle and releasing the new varieties to farmers. Finally, the technology may potentially be useful in the future for the introduction of Robusta coffee species (if deemed necessary) whose multiplication is limited to vegetative (clonal) reproduction or micro-propagation.
“This technology will support the sustainable exploitation of the genetic, agronomic and economic potential of Saudi coffee genotypes as we strive towards positioning the Saudi coffee in the global map,” said Kakoli Ghosh, Chief Technical Adviser, SRAD Project.
