About this Research Topic
Intercropping, also known as mixed cropping, has a great potential for enhancing water and nutrient use efficiency and improving plant productivity and resilience to biotic and abiotic stress, including those triggered by climate change. For example, species or cultivar mixtures in forestry and agriculture, including forage crops, can reduce fossil energy and chemical inputs, and enhance ecosystem services compared to the stands of pure species or cultivars. Despite their manifold benefits, the practice of intercropping has not risen above its niche status in many regions of the world. The selection of varieties specifically adapted to intercropping has been recognized as a major practical challenge to its widespread deployment, because plant breeding so far has focused almost exclusively on the cultivation of pure stands. There is increasing evidence that yield figures assessed in pure stands do not predict well yield performance in mixed stands due to local selection pressures along with plasticity generated by the inter-specific neighbor interactions occurring in mixtures. The identification of traits or genes involved in resource complementarities and spatio-temporal interactions for specific species or cultivar combinations show great promise to develop dedicated breeding and improve the potential of intercropping.
New breeding schemes, selection criteria (traits) and ideotypes, plant modelling at individual and stand level, and novel phenotyping approaches are key topics at the core of research studies on breeding for intercropping. The two concepts “mixing ability” (MA) and “evolutionary plant breeding” (EPB) can be applied or adapted to exploit selective pressures within species or cultivar mixtures. MA and EPB approaches should be complemented with functional approaches and modelling in order to limit the large number of species or cultivar combinations to be tested. This Research Topic aims to gather new insights in the areas of quantitative genetics, ecology, ecophysiology, agronomy and forestry integrating theoretical, experimental as well as participatory approaches.
This Research Topic welcomes the submission of Reviews, Mini Reviews, Methods, Opinion, and Original Research manuscripts aiming to address recent breeding-related developments in intercropping research falling under, but not limited to:
• Morphological and functional plant traits and ideotypes involved in species or cultivar interactions
• Plant modelling at individual or stand scale to explore the large range of trait combinations, quantify effects of traits, predict how different trait combinations affect performance of species or cultivar mixtures and determine the resource ecological niche adapted to each species or cultivar in mixtures
• Screening systems (including experimental designs and statistical methods) and novel non-destructive high-throughput phenotyping approaches to screen species or varieties within the existing genetic resources that take GxE and GxM interactions into account, complemented with functional approaches based on ecological niche concepts and interaction traits
• Genetic studies (GWAS, QTL detection on segregating populations, mutant analysis, etc.) highlighting the genetic architecture of plant-plant interactions
• New breeding schemes for species or cultivar mixtures based on MA, EPB and key trait approaches
Image credit: Pierre Hohmann.
Keywords: Intercropping, Mixing ability, Evolutionary plant breeding, Trait combination, Participatory breeding
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.