About this Research Topic
It is estimated that there are between 300'000 and 500'000 species of higher plants, of which approximately 369'000 have been identified or described. Many species are still unknown to science, while perhaps a third of it is at risk of extinction. The number of plant species used for food by pre-agricultural human societies is only a small fraction of the diversity of the plant kingdom that was domesticated.
The process of crop domestication was based on selection driven by human cultivation practices and agricultural environments. Approximately 2'500 species have undergone some degree of domestication, and 250 species are considered to be fully domesticated. Humanity relies on a small collection of crop plants such as corn, rice, wheat, soybean, and potatoes constituting the majority of our dietary intake. Altogether, some 10-50 plant species together provide about 95% of the world’s calorie intake. This concentration on a few species for most food is a key element of the vulnerability of the world food supply to the impact of climate change and the outbreak of new major plant diseases.
Crop wild relatives (CWR) remain the largest reservoir of genetic diversity for crop improvement and have been utilized for major gene disease and pest resistance, and abiotic stress tolerance. However, a large set of plant species with favorable traits has yet to be domesticated. As we have been gaining knowledge on the genomic and biological background of domestication processes, we can apply more effective selection to domesticate wild species. Since many wild taxa are locally adapted to particular habitats and contain significant genetic diversity, this might lead to novel crops while increasing potential adaptation to novel production environments, and help us achieve more environmentally sustainable agriculture as we face climate change. While conventional breeding by hybridization and progeny selection augmented by marker-assisted selection are likely to be the most practicable approaches for the time being, recent developments in genome-editing technologies, genomic selection, and inoculation of plants with beneficial microbes may help accelerate this process in the future by converting key domestication genes from wild to domesticated forms.
In this Research Topic, we aim to collect a set of innovative papers at the frontiers of wild plants as sources of new crops. In particular, we welcome contributions on the following topics:
- De novo domestication of plant species. This includes not only work with wild relatives of existing crops but also domestication of entirely new species with suitable traits, the work leading to the assessment of such species and traits suitable for targeting. Biological and ethnobotanical knowledge can help to identify suitable candidates. This process will provide the opportunity to have better locally adapted crops.
- Use of crop wild relatives to broaden genetic diversity of crops. It is known that crop wild relatives harbor larger genetic diversity than crops, this can be efficiently used to make current crops more resilient to biotic and abiotic stress including climate change.
- Use of perennial species. Past domestication process has favored annual growth habit on the expense of demanding agriculture practices impacting ultimately negatively on the environment, the incorporation of perennial crops, including cereals, would allow more environmentally friendly and sustainable production
- Novel domestication syndromes and re-imagined ideotypes. During the domestication process common sets of traits (domestication syndrome) have been modified. This, however, has inevitably narrowed today's crop genetic and biological ranges. Modern agriculture has different requirements for cultivation and harvest than in the past. Moreover, scientific knowledge and breeding experience have identified new crop ideotypes.
- Crop weedy relatives constitute a special case of CWR, providing both opportunities for utilization by breeders and challenges for farmers. In relation to crops, proximity to weedy relatives can permit gene flow, transgene escape, and both seed and crop contamination. Yet, locally adapted weedy relatives may provide needed sources of genes conferring local adaptation, and may even be candidates for de novo domestication oriented toward novel ideotypes.
- The development of genetic knowledge and genomic resources such as whole genome assemblies is particularly challenging in polyploid crops, drawing attention to wild, diploid relatives as potentially attractive model systems. The genetic basis for domestication trait variation is likely to be simpler to dissect at the diploid level, and key domestication traits may have their origins in specific diploid ancestors and therefore reside in specific subgenomes.
Keywords: Crop Wild Relatives, Domestication, Ethnobotany, Edible Wild Plants, Genetic Diversity
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