E. T. Lammerts van Bueren

Developments in breeding cereals for organic agriculture

The need for increased sustainability of performance in cereal varieties, particularly in organic agriculture (OA), is limited by the lack of varieties adapted to organic conditions. Here, the needs for breeding are reviewed in the context of three major marketing types, global, regional, local, in European OA. Currently, the effort is determined, partly, by the outcomes from trials that compare varieties under OA and CA (conventional agriculture) conditions. The differences are sufficiently large and important to warrant an increase in appropriate breeding. The wide range of environments within OA and between years, underlines the need to try to select for specific adaptation in target environments. The difficulty of doing so can be helped by decentralised breeding with farmer participation and the use of crops buffered by variety mixtures or populations. Varieties for OA need efficient nutrient uptake and use and weed competition. These and other characters need to be considered in relation to the OA cropping system over the whole rotation. Positive interactions are needed, such as early crop vigour for nutrient uptake, weed competition and disease resistance. Incorporation of all characteristics into the crop can be helped by diversification within the crop, allowing complementation and compensation among plants. Although the problems of breeding cereals for organic farming systems are large, there is encouraging progress. This lies in applications of ecology to organic crop production, innovations in plant sciences, and the realisation that such progress is central to both OA and CA, because of climate change and the increasing costs of fossil fuels.

Ecological concepts in organic farming and their consequences for an organic crop ideotype

Abstract Currently, organic farmers largely depend on varieties supplied by conventional plant breeders and developed for farming systems in which artificial fertilizers and agro-chemicals are widely used. The organic farming system differs fundamentally in soil fertility, weed, pest and disease management, and makes higher demands on product quality and yield stability than conventional farming. Organic farming systems aim at resilience and buffering capacity in the farm-ecosystem by stimulating internal self-regulation through functional agrobiodiversity in and above the soil, instead of external regulation through chemical protectants. For further optimization of organic product quality and yield stability new varieties are required that are adapted to organic farming systems. The desired variety traits include adaptation to organic soil fertility management, implying low(er) and organic inputs, a better root system and ability to interact with beneficial soil micro-organisms, ability to suppress weeds, contributing to soil, crop and seed health, good product quality, high yield level and high yield stability. In the short run, organic crop ideotypes per crop and per market segment can help to select the best varieties available among existing (conventional) ones. However, until now many of the desired traits have not received enough priority in conventional breeding programmes. Traits like adaptation to organic soil fertility management require selection under organic soil conditions for optimal results. The limited area of organic agriculture will be the bottleneck for economic interest in establishing specific breeding programmes for organic farming systems. The proposed organic crop ideotypes may benefit not only organic farming systems, but in the future also conventional systems that move away from high inputs of nutrients and chemical pesticides.

The role of molecular markers and marker assisted selection in breeding for organic agriculture

Plant geneticists consider molecular marker assisted selection a useful additional tool in plant breeding programs to make selection more efficient. Standards for organic agriculture do not exclude the use of molecular markers as such, however for the organic sector the appropriateness of molecular markers is not self-evident and is often debated. Organic and low-input farming conditions require breeding for robust and flexible varieties, which may be hampered by too much focus on the molecular level. Pros and contras for application of molecular markers in breeding for organic agriculture was the topic of a recent European plant breeding workshop. The participants evaluated strengths, weaknesses, opportunities, and threats of the use of molecular markers and we formalized their inputs into breeder’s perspectives and perspectives seen from the organic sector’s standpoint. Clear strengths were identified, e.g. better knowledge about gene pool of breeding material, more efficient introgression of new resistance genes from wild relatives and testing pyramided genes. There were also common concerns among breeders aiming at breeding for organic and/or conventional agriculture, such as the increasing competition and cost investments to get access to marker technology, and the need for bridging the gap between phenotyping and genotyping especially with complex and quantitative inherited traits such as nutrient-efficiency. A major conclusion of the authors is that more interaction and mutual understanding between organic and molecular oriented breeders is necessary and can benefit both research communities.

Organic agriculture requires process rather than product evaluation of novel breeding techniques

In organic agriculture the use of genetically modified organisms (GMOs) is banned. Recently, two novel breeding techniques have been developed, i.e., cisgenesis and reverse breeding, both of which are based on gene technology but should raise less moral concerns from the public. Whether the products of these breeding processes are classified as GMOs depends on the interpretation of the relevant EU regulations. In cisgenic plants, the genes introduced through genetic modification are from a crossable donor plant so that the source of the genes is considered to be of the same nature. In reverse breeding, the recombinant genes, essential to the breeding process, are no longer present in the product resulting from the entire breeding process, and thus the product as such is not transgenic. Should varieties obtained through cisgenesis or reverse breeding be allowed in organic agriculture? The answer to this question depends on whether the product or the process of breeding is taken into account. Assessment based on the product implies a choice of an ethical approach that only considers the extrinsic consequences of human action by making a risk-benefit analysis. It neglects so-called intrinsic, ethical arguments related to the applied technology (the process) itself. The organic movement uses the intrinsic argument of ‘unnaturalness’ against genetic engineering. We therefore conclude that products of cisgenesis and reverse breeding should be subject to the current GMO-regulations in organic agriculture and should thus be banned from organic agriculture.

The value of ‘naturalness’ in organic agriculture

Producers, traders and consumers of organic food regularly use the concept of the naturalnatural to characteri ze organic agriculture or organic food. Critics sometimes argue that such use lacks any rational (scientific) basis and only refers to sentiment. We carried out research to (1) better understand the content and the use of the concepts of nature and the natural in organic agriculture, (2) to reconstruct the value basis underlying the use of the concept of the natural in organic agriculture, and (3) to draw implications for agricultural practice and policy. A literature study and the authors’ own experience were used to produce a discussion document with explicit statements about the meaning of natural in the different areas of organic agriculture. These statements were validated by means of qualitative interviews with stakeholders. The concept of nature or the natural appeared to be value-laden. The value basis is a normative reconstruction that cannot just be derived from the use of the word natural by organic stakeholders. For this reconstructed concept the word naturalness is used. Naturalness thus becomes an ethical value for organic agriculture, an inspirational guide for organic stakeholders. The value of naturalness refers to a basic respect for the intrinsic value of nature, i.e., the value nature has, independent of the benefits it may have for humans. This manifests itself in three ways: (1) in the use of natural substances, (2) in respecting the self-regulation of living organisms and ecosystems, and (3) in respecting the characteristic (species-specific) nature of living organisms. If organic stakeholders limit themselves to using natural substances it is called the no-chemicals approach. If they also respect the self-organization of living organisms the authors call it the agro-ecological approach. If also the normative element of naturalness is included, it is called the integrity approach.

Organic propagation of seed and planting material: an overview of problems and challenges for research

By 1 January 2004, as a result of EU-regulation 2092/91 for organic farming, the organic sector needs to have developed efficient schemes to be able to use adequate quantities of organically produced seed and planting material. Market problems and agronomic problems that are related to obtaining sufficient quantities of adequate quality are reviewed. For successful production of organic seed and planting material intensive communication between and mutual commitment of farmers, traders, breeders and governmental organizations are necessary. Farmers together with traders should be involved in variety testing and in designing crop ideotypes by identifying the desired cultivar(s) and variety traits. Breeders can contribute by incorporating the desired organic traits in future breeding programmes. In addition, a great effort is needed to develop empirical knowledge and research-based information on adapting and improving cultural practices for organic seed production, developing resistant cultivars for healthy seed production, developing protocols for seed health testing, assessing disease threshold values, and designing organic seed treatments. The EU-regulation should be strictly enforced, no longer allowing derogation of the use of conventional seeds after 2003 for those crops for which diverse, high quality seed or planting material of organic origin is available. It is expected that by 1 January 2004 enough seed or planting material will be available for most crops. But continuous optimizing of organic seed production management will be required to enlarge the cultivar assortment and to control the quality of organic seed and planting material

Preface to the special issue: Plant breeding for organic and sustainable, low-input agriculture: dealing with genotype-environment interactions

In Europe, agriculture is increasingly moving towards organic and sustainable, low-input farming systems. These agricultural practices, however, have various constraints that still need to be solved. One of the major constraints of organic farmers is that they largely depend on crop varieties produced for conventional farming systems with high inputs of artiWcial, mineral fertilizers and chemicals for crop defense. Therefore, the organic sector urgently requires breeding programmes for robust varieties, which are better adapted to low-input conditions, with traits such as improved rooting systems, stronger interspeciWc competition ability for weed suppression and yield stability. An important aspect in the breeding for such varieties is the choice for an appropriate selection environment or a combination of environments: organic versus conventional and highversus lowinput conditions. Recognising the above mentioned constraints and the need to explore alternative strategies to overcome these constraints, hereby also using insight and knowledge from agronomic Welds working at a higher aggregation level (i.e. system level), the Wrst EUCARPIA meeting of the Section Organic plant breeding and low-input agriculture was organised in Wageningen, the Netherlands, from 7 to 9 November 2007. This symposium was organised in close cooperation with COST860 SUSVAR, the European Consortium for Organic Plant breeding (ECO-PB), ISOFAR section Plant Breeding and Seed Production, the C.T. de Wit Graduate School for Production Ecology and Resource Conservation (PE&RC) and the Chair Organic Plant Breeding of Wageningen University. Some 130 participants representing 28 countries attended the symposium, including students, researchers and other professionals from universities, institutes and breeding companies. The programme featured 17 oral and 47 poster presentations, covering the topic areas of genotype–environment interaction, breeding strategies, selection criteria and methods, and participatory breeding approaches. A book of abstracts was available at the symposium including abstracts of all the presentations, see www.eucarpia.org. A selection of presentations were regarded as representing the four topic areas and are combined as full papers in this special issue of Euphytica, the international plant breeders’ journal. We are grateful to the editor-in-chief professor Dr. Richard Visser, for supporting the publication E. T. Lammerts van Bueren (&) Wageningen UR Plant Breeding, Wageningen University, P.O. Box 386, 6700 AJ Wageningen, The Netherlands e-mail: edith.lammertsvanbueren@wur.nl

Can conventional breeding programmes provide onion varieties that are suitable for organic farming in the Netherlands

Main stream commercial onion breeders do not select varieties for organic farming, but solely for conventional farming. Seed companies consider the organic market too small to justify investments in breeding for this sector. In order to study if their varieties also suit organic farmers’ needs we interviewed four Dutch commercial onion breeders on their breeding programme and selection criteria and compared the outcome with a variety profile composed of the priority traits of Dutch organic farmers. Breeders gave priority to the same storage and bulb quality traits that are demanded by organic farmers, because organic onions are exported to conventional supermarkets that apply the same quality standards to organic and conventional onions. However, organic farmers also need varieties that perform well in the field. Breeders give low priority to field selection. Furthermore, three of the four seed companies only breed hybrids. The cytoplasmic male sterility system used to produce these hybrids does not comply with organic principles. We conclude that at present breeders can provide varieties that meet organic farmers’ demands for storability and quality traits, but they should give higher priority to field selection to also improve required field traits. The latter will only occur, if in future the organic seed market will grow. If the organic sector wants varieties developed according to its own principles, it should either set up its own onion breeding programme or seek alliances with breeding companies that are prepared to harmonize their breeding methodology with the organic principles.

The consequences of the concept of naturalness for organic plant breeding and propagation

Organic agriculture is enhancing specific plant breeding activities to meet its requirements for varieties better adapted to the specific organic environment. In the past five years, therefore, attempts have been made to translate the principles of organic farming into rules, regulations and guidelines for organic plant breeding and propagation. These principles are based on the concept of naturalness, which includes three complementary approaches: the non-chemical approach, the agro-ecological approach and the integrity approach. Departing from the concept of naturalness, criteria have been developed to evaluate existing plant breeding and propagation techniques for their compliance to the principles of organic agriculture. Each of the three approaches of the concept of naturalness has major consequences. If these consequences are taken seriously, plant breeding and propagation strategies and techniques for organic farming will greatly differ from breeding and propagation for conventional farming. To better understand the choices to be made and to make them acceptable to the mainstream seed industry, it is necessary to further clarify the underlying framework. This paper provides this clarification by analysing the cognitive, emotive, and normative dimensions of the three approaches. Distinguishing the three different approaches of naturalness in organic agriculture, as well as their three dimensions, and analysing the consequences for the breeding and propagation strategies and techniques can also help to identify and prioritize short-term and long-term steps for the practical development of organic seed production and plant breeding.

Broadening the genetic base of onion to develop better-adapted varieties for organic farming systems

SummaryAs organic farming refrains from high and chemical inputs it needs varieties better adapted to organic conditions to improve the yield stability and quality of crops. In order to make genebank accessions more accessible for the utilisation in organic breeding programmes, a participatory research project with farmers was carried out in 2002 and 2003. From the Dutch genebank collection 37 onion accessions, divided into five different groups (according to their market use), were selected and planted at a commercial organic farm. Farmer participation in characterisation and evaluation of the material resulted in including additional plant traits for genebank characterisation as well as new selection criteria for breeding. It also provided researchers insight into how organic farmers evaluate and value certain plant traits. Variation for important properties was found within and between the five groups. To establish base populations, the farmers, in collaboration with the researchers, selected the best genotypes within the five groups of onion accessions. The new base populations may be exploited in order to achieve better-adapted material for organic farming systems.