Breeding Late Blight Resistant Potatoes for Organic Farming—a Collaborative Model of Participatory Plant Breeding: the Bioimpuls Project

Abstract

In organic potato production, the need for varieties with durable late blight resistance developed through classical breeding programmes is urgent. Besides late blight resistance, other variety characteristics needed in organic potato production are early canopy closure for weed suppression and good tuber dormancy to eliminate the need for (chemical) sprouting inhibition during storage, amongst others. This paper is a unique example of collaboration between researchers, farmers and professional breeders of both large, medium and small breeding companies. The aim of the resulting breeding project, Bioimpuls, was to provide a substantial impulse to both the organic and conventional potato breeding sector by enlarging the access to various sources of late blight resistance. The Bioimpuls activities include providing true seed populations for variety selection with five available sources of R-genes against Phytophthora infestans, early and advanced introgression breeding with six new R-genes, and education and communication. The results achieved over the 11-year period (2009–2019) are analysed. Many true seed populations containing multiple resistance genes are produced and selected, and a constant flow of breeding clones is entering the evaluation and positioning trials of companies. However, it will still take a considerable amount of time before varieties with stacked resistance genes will replace the new resistant single gene varieties entering the market in the next few years. Five out of six new sources of R-genes need more years of backcrossing before they are ready for commercial use. Bioimpuls successfully introduced a training course for farmer breeders, and published a manual for potato breeding.

How the Seed of Participatory Plant Breeding Found Its Way in the World through Adaptive Management

“…In the PPB case of the late blight-resistant potato in the Netherlands, the seed companies were already involved in the PPB program as actors; however, the missing actors to adopt the new PPB varieties were supermarkets. A separate action was needed by the Dutch umbrella organization for organic agriculture to convince retailers of the value of the new disease-resistant PPB varieties, which ultimately succeeded in creating a covenant among all Dutch supermarkets to replace the current late blight susceptible varieties with more robust PPB varieties over time [35]. In other PPB projects, aiming at resistant varieties, such as scab-resistant apples and mildew-resistant grapes, benefitting farmers in the first place, demonstrated the need to find alternative ways to involve the market actors in accepting the new varieties and communicate the added value to consumers [36].…”

Late blight resistance genes in potato breeding

“…Successive rounds of bridge crosses between ABP (4x) and S. tuberosum , led to produce ABPT plants which, after three backcrossing to S. tuberosum , eventually led to registration in 2006 and 2008 of two P. infestans resistant cultivars Toluca and Bionica (Haverkort et al 2016 ). Another example of the introduction of Rpi genes into the potato gene pool is the 11-year-long project Bioimpuls, which resulted in the development of true seed population with single or multiple Rpi genes against late blight through classical breeding (Keijzer et al 2021 ). In this project, three groups of sources of resistance to P. infestans were distinguished.…”

“…The third group is potato wild species that have not been used so far, including S. brachycarpum , S. bukasovii , S. iopetalum , S. multiinterruptum , and S. sucrense. This group needs two or three additional rounds of backcrossing to be used for commercial crosses (Keijzer et al 2021 ).…”

Exploring the emergence of participatory plant breeding in countries of the Global North – a review

“…Potato is one of few vegetatively propagated root crops that are involved in participatory breeding programmes in the Global North: in the Netherlands (Lammerts van Tiemens-Hulscher et al, 2012;Keijzer et al, 2021), Germany (Sieber et al, 2018) and CA (Entz, 2019), US (Genger, 2018) (Table 5). The reasons for starting such programmes are the lack of available organically produced seed potatoes (CA and US).…”

“…Many projects stated the goal of improving adaptation to organic farming environments, but projects were also motivated by organic principles and values. The current study identified that projects commonly prioritized breeding goals of improving traits crucial to organic producers that are not a priority in conventional breeding programmes, for example, the case of resistance to late blight (P. infestans) in potatoes (Keijzer et al, 2021) and seedling vigour in cool soil conditions in sweet maize (Shelton and Tracy, 2016).…”