In current agriculture, abiotic and biotic stress are the main reasons that yield potential and quality aspects are difficult to realize for many crops. Resistance breeding focuses on the use of genetic resources for improving plant defence against stress factors. Breeding for biotic stress resistance addresses with defence mechanisms and strategies that protect host plants against pests and pathogens, inheritance of resistance genes, and durable effectiveness of resistance genes. Abiotic stress is caused by environmental factors (a.o. temperature, water, nutrients, minerals). Breeding for abiotic stress resistance and tolerance to such factors addresses concepts such as adaptability and stability of crop plants, mechanisms of stress tolerance and phenotyping for selection, genotype by environment interaction and selection in multi-environment trials. Differences between plant genotypes and assessment of the importance of these effects can be quantified in experiments with appropriate experimental designs and using statistical analysis of the collected data.
Quality breeding is mainly directed at improving plant compounds like carbohydrates, proteins, vegetable fats and oils, fibres and secondary metabolites, that are all synthesized in metabolic pathways. Breeding objectives include improved product quality (e.g. taste, shelf life), enhanced production of flavours, fragrances and health-supporting components, absence of allergens and other undesirable compounds and improvement of processing characteristics of plant raw materials.
