Charmaine Stander serves on the management team of the Tissue Culture Facility (TCF), a newly established facility that aims to address shortages of plant material – specifically rootstocks required by the deciduous fruit industry. This state-of-the-art facility near Paarl employs biotechnology to provide growers with phytosanitary-accredited plant material, and specialises in the multiplication of new-generation clonal rootstocks for the local fruit and wine industry.
The facility has six shareholders: Hortgro Stone, Hortgro Pome, the Canning Producers’ Association, SATI, Raisins South Africa, and the SAPO Trust. In addition, the Western Cape Department of Agriculture supports the TCF by facilitating the import of new varieties through tissue culture quarantine.
Stander focused her presentation on the progress made over the last two years towards establishing the TCF.
She explained that the term ’tissue culture’ refers to a collective of techniques used to maintain or grow plants cells, tissue or organs under sterile conditions. These conditions help to ensure that the plant materials grown at this facility are free of fungi, bacteria and disease.
The benefits of micro-propagation
The TCF employs the technique of micro-propagation to grow plant material. This entails the vegetative multiplication of identical genetic material in a sterile environment. This particular tissue culture technique offers many benefits, including cost-effectiveness. Another bonus is that micro-propagation does not depend on the season or the weather, Stander said. It helps supply growers with virus- and disease-free plant material throughout the year and can be used to grow more uniform and vigorous plants.
Using tissue culture in the provision of plant material is a global trend in the agricultural industry, she pointed out. It is currently the fastest growing area of biotechnology, with a wide range of applications in crop production. By embracing this innovation, Stander said, the South African fruit industry can make sure to keep up with its competitors.
“The most important part of this whole process is the health of the plant material that you start with,” she said. “We need healthy mother plant material that is virus-free and without any signs of disease. And, of course, we want to know that it’s true to type. So, DNA analysis needs to be done on this material so that we can be 100% sure that we are starting with the correct material.”
The TCF also has quarantine capacity and will be focusing on providing better and improved plant material for the local fruit industry. Furthermore, the facility will create opportunities to export quarantined plant material to neighbouring countries and, at the same time, serve as a quarantine station for the importing plant material into SA, Stander said.
Although the TCF is, at this stage, still producing small volumes of plant material, it is gearing up for increased production by optimising its growth medium and also the protocols for growing specific cultivars.
The facility will supply apple, cherry, stone fruit and grapevine rootstocks (including 143B, RS3, Paulsen, and Ramsey).
Choose better plant material to grow better crops
Choosing plant material of good genetic quality can significantly affect production. Stefan Jordaan (Raisins South Africa’s research development manager) focused his presentation on the impact of quality plant material on yield in the long run. Research is underway to quantify the monetary impact of decisions about new planting material and explore the benefits of paying a premium for better quality grapevines.
In 1954 already, the Department of Agriculture identified the physical and genetic status of plant material as one of the most critical factors contributing to agricultural production in SA, Jordaan pointed out.
Decisions regarding plant material quality are becoming increasingly important to ensuring sustainable production and proper yield on farms, he indicated.
The Vine Improvement Association (VIA) is the delegated authority that coordinates vine improvement in SA and administers the South African Plant Certification Scheme for Vitis. The association’s mission is to promote the South African wine, table and drying-grape industry through plant improvement and the certification of propagated vine material, Jordaan said.
The scheme is not compulsory – any nursery, an organisation representing producers, or one that imports, breeds or selects new varieties is free to participate. Even so, the production of over 90% of all wine grapes is managed within the scheme. Approximately half of the table and drying-grape vines produced annually are certified by this scheme.
Jordaan said producers wanting to secure quality plant material should order their plant material well in advance (i.e. the year before they want to establish new grapevines).
Planting grapevines that adhere to minimum industry standards only can have costly implications for local growers in the long term, Jordaan warned.
“Is it worth paying attention to the quality of plant material? Definitely,” he said. “Producers cannot always control rising costs, including those related to labour, fuel and electricity. But they can increase their income from day one by choosing grapevine plant material of good quality.”
