Towards the Genomic Basis of Local Adaptation in Landraces

Abstract

Landraces are key elements of agricultural biodiversity that have long been considered a source of useful traits. Their importance goes beyond subsistence agriculture and the essential need to preserve genetic diversity, because landraces are farmer-developed populations that are often adapted to environmental conditions of significance to tackle environmental concerns. It is therefore increasingly important to identify adaptive traits in crop landraces and understand their molecular basis. This knowledge is potentially useful for promoting more sustainable agricultural techniques, reducing the environmental impact of high-input cropping systems, and diminishing the vulnerability of agriculture to global climate change. In this review, we present an overview of the opportunities and limitations offered by landraces' genomics. We discuss how rapid advances in DNA sequencing techniques, plant phenotyping, and recombinant DNA-based biotechnology encourage both the identification and the validation of the genomic signature of local adaptation in crop landraces. The integration of 'omics' sciences, molecular population genetics, and field studies can provide information inaccessible with earlier technological tools. Although empirical knowledge on the genetic and genomic basis of local adaptation is still fragmented, it is predicted that genomic scans for adaptation will unlock an intraspecific molecular diversity that may be different from that of modern varieties.Keywords: genomics; differentiation; genome-environment association Crop LandracesPublic awareness on the importance of biodiversity conservation is strengthening over time [1]. Climate change, pollution, environmental disasters, loss of natural habitats, environmental degradation, and overexploitation of resources regularly make front-page news. Without taking into consideration the impact of the measures implemented to avoid biodiversity loss, large attention is generally given to wild species, especially those at risk of extinction [1,2]. Agricultural biodiversity (i.e., the variety and variability of animals, plants, and microorganisms that are used directly or indirectly for food and agriculture [3]) is largely regarded as a subset of biodiversity. However, agriculture and biodiversity are closely tied. Their mutual dependence is crucial not only to ensure yield today, but also to contribute to a more resilient, sustainable agriculture. This includes the development of solutions for water-saving technologies and for minimizing the detrimental effects of global climate change on crops [4,5].Plant genetic resources for food and agriculture (PGRFA) are the central components of agricultural biodiversity because they constitute the primary elements of the production process. Crop improvement relies on genetic diversity. Taking into account the trends and efforts of modern breeding, the main part of genetic diversity of cultivated species is expected to be found in traditional varieties, also known as landraces. It is not easy to provide an all-p...

Influence of CNV on transcript levels of HvCBF genes at Fr-H2 locus revealed by resequencing in resistant barley cv. ‘Nure’ and expression analysis

“…Analysis of structural variations -such as CNV, INDELs and movement of transposable elements -was reported to be often related to environmental adaptation in crop plants. Alteration in copy number of genes/gene families caused by natural and man-driven (breeding) evolution may underlie the phenotypic variation of agronomically important traits [25,26]. In particular, in barley and other Triticeae crops, CNV was identified at Ppd-B1 and Vrn-A1 flower response loci [27], and Vrn-H3 loci [28,29]Boron and Aluminum toxicity tolerance loci [26,27].…”

On-Farm Crop Diversity for Advancing Food Security and Nutrition

“…Such practices will be even more essential as the effects of climate change become more frequent and profound. Many farmers' varieties/landraces are suited to local ecosystems, climatic conditions and farming practices, and have been shown to be more resilient to unpredictable and hardy conditions [8,[39][40][41][42].…”

Dynamics of Fertility-Related Traits in Tomato Landraces under Mild and Severe Heat Stress

“…These traits raise great interest for both the valorization of traditional tomatoes and the use of ‘traditional’ genes in breeding programs. Landraces also represent a valuable experimental material to understand the mechanisms that underlie the variation in fertility in response to heat [ 39 ] or other abiotic [ 40 ] challenges.…”