52 I EUROPEAN SEED I EUROPEAN-SEED.COM O f the top 10 food crops in the world, potato comes in at the third place, and is also the number one non-grain food product. Originally grown in the Andes, the Spanish introduced the potato to Europe in the 16th century, and, after a bumpy start, potatoes have been a very popular food source in the past two cen- turies. The potato offers a healthful low calorie, high fibre food that offers signif- icant protection against cardiovascular disease and cancer. Additionally, potato tubers are a very good source of vita- min B6 and a good source of potassium, copper, vitamin C, manganese, phos- phorus, niacin, dietary fibre, and panto- thenic acid. They also contain a variety of phytonutrients that have antioxidant activity. No wonder this is such a beloved crop across the globe. European Seed sat down with some of the major potato breeding companies in Europe to learn more about the challenges and opportu- nities of breeding new potato varieties. Piet Smeenge, Director of Kweekbedrijf Smeenge-Research, Vanessa Prigge, Project Manager Crop Improvement at Solana, Gerard Backx, CEO of HZPC, Jan-Paul Bandsma, Product manager at de Nijs Potatoes, and Guus Heselmans, manager R&D of C. Meijer B.V. provided insight on this heavily favoured crop. POTATO BREEDING VERSUS THE BREEDING OF SEED CROPS Smeenge states that potato-breeding takes a lot of time as there can be only one selection per year. He says in total it takes 10-12 years before protection and listing. “With seed-crops, hybrid breed- ing is possible, so there you only need a few years for creating new varieties. In potato, hybrid-breeding is (still) not pos- sible, however, KWS, Solynta, HZPC and Bejo are working on it. So maybe it will be possible in the coming 10 years.” Backx concurs, indicating that the multiplication rate of a vegetatively prop- agated crop is much slower, making the selection process slower and the intro- STARCH TREKWHAT IT TAKES TO BREED A NEW POTATO VARIETY. BY: MARCEL BRUINS Potato trials in Scotland (Smeenge Research) duction phase longer. “Hence, much more years are required.” He says on the other hand, the maintenance of the genetics is simple as the genetics do not change. In general, vegetatively propagated crops have a much more complex genome, which is the biggest hurdle. “Potato is tetraploid and enormously heterogeneous. Working with diploid plants is possible, but so far this is only done in a research phase. Apart from that, double haploids might be an option, but not an easy route.” Bandsma agrees: “When you have a good variety produced by the vegeta- tively way, you know what kind variety you will get after multiplication (always the same). In a seed propagated crop there is always difference in the progeny. Although potatoes are multiplied vegeta- tively, it is possible to improve a variety by traditional stem selection. For example, you can improve tuber count, tuber shape or other things.” The main challenges associated with the vegetative nature of potato produc- tion are the low multiplication rate and the high risk of transmission of tuber- borne diseases. Prigge says in maize for example, with the seeds of one single testcross ear you can sow yield trials in several locations, even in replicated designs, already in the first field year. In potato in contrast, it easily takes beyond the fourth field year to reliably assess tuber yield performance in a similar experimental design due to the low multiplication rate of less than 15 tubers per plant which means that the first years are dedicated to tuber production for testing purposes. “This clearly lengthens the breeding cycle and also impacts the selection deci- sions: at the time of the first yield trials, out of necessity due to limited storage capacity for this bulky crop, more than 99% of the original material may already have been discarded based on visually assessable traits such as tuber traits and breeder’s visual preference. In addition, every multiplication cycle bears the risk of infection with tuber-borne diseases, especially viruses, so that extensive test- ing of tuber samples from each selected genotype is performed.” She says another major disadvantage of the vegetative propagation is the ease of farm-saved