PRODUCING HEALTHY SEED POTATO TUBERSThe Potato Laboratory produces disease-freepotatoes for the Seed Certification Schemethrough a process called micropropagation

BackgroundDisease-free seed at planting is a prerequisite for aproductive crop. The potato is propagatedvegetatively and is prone to seed degeneration fromcontinued multiplications and the accumulations ofpathogens (particularly viruses), from onegeneration to the next. Most countries have formal

systems in place, usually referred to as SeedCertification Schemes, which include variousproduction steps whereby a ‘flush-through’ systemis applied to renew seed stocks. The Department of Agriculture, Fisheries and Foodoperate the Seed Potato Certification Scheme. ThePotato Laboratory maintains a collection of morethan 300 virus-free potato varieties and providesnew seed through the process of micropropagationeach year to seed potato growers participating inthis Scheme.

Potato Laboratory, Tops, Raphoe, Co. Donegal.Tel: (074) 9145488 / 9145490, Fax: (074) 9145262

Step 1Tubers from virus-tested plants, which have been tested for bacterial-rotdiseases, are allowed to sprout in the laboratory.

Step 3The meristem develops to form a microplant.

Step 4The microplant is cut to give nodal cuttings.

Step 5Nodal cuttings are planted in solid growth medium. Eachnodal cutting produces a new microplant. Step 4 is repeateduntil the required number of microplants is produced.

Step 7Minitubers are harvested, stored in a cold room and sold on to seed growersthe following spring.

Step 6Microplants are transplanted into soil-free compost in anaphid-proof plastic tunnel or glasshouse and allowed growfor up to 100 days.

Step 2Sprouts are removed from the tuber and surface-sterilised. The meristem(tissue found at the growing point of all plants and free from pathogens) is cutfrom the sprout tip under a dissecting microscope and transferred to a liquidgrowth medium.

Steps in Potato Micropropagation