Sustainable Stewardship of the Landrace Diversity

Abstract

Landraces are heterogeneous populations and their variability goes through continuous alterations because of physical, genetic, and epigenetic procedures exacerbated by the ongoing climatic changes. Appropriate stewardship of landrace diversity is pivotal to promote its longevity in a manner that is sustainable from the farming perspective. A seed multiplication procedure is presented based on the assumption that in order to improve effectiveness in resource use and increase seed productivity, landraces should comprise genotypes which minimize intra-species competition. These aforementioned genotypes should be of the "weak competitor" ideotype, which are selected so as to alleviate the interplant competition and reach as high as possible crop stand uniformity. Stand uniformity is essential to ensure the same growing conditions for each plant. Reduced intra-crop inequality and equal use of inputs by individual plants will optimize crop performance. Precisely, the "weak competitor" is most often of high yield potential due to a negative association between yielding and competitive ability. Therefore, the suggested procedure involves initial reproduction at nil-competition (widely spaced plants to preclude any plant-to-plant interference for inputs) where "off-type" and low yielding plants are omitted, followed by subsequent multiplication at dense stands. This may represent an effective cultural practice to improve also the landrace health status concerning seed-borne diseases in the absence of certification systems.

Yield and Stability for agronomic and seed quality traits of common bean genotypes under Mediterranean conditions

“…These results indicate that the Li and Mi could be considered as wide adaptation cultivars, whereas Ch is a promising genetic material with high yield potential. Wide adapted cultivars are of great importance, especially due to the ongoing climate change (Tokatlidis and Vlachostergios, 2016). On the other hand, the landrace Ch constitutes a valuable source of genetic diversity and breeding efforts should be targeted in its exploitation.…”

Intense Breeding within Lentil Landraces for High-Yielding Pure Lines Sustained the Seed Quality Characteristics

“…Based on the well-established negative relationship between genotype yield and competitive ability, breeding in conditions that ensure nil-competition instead of dense stand, and applying single-plant yield as the main selection criterion puts additional emphasis on highlighting the "weak competitor of high plant yield efficiency" ideotype [30]. The hypothesis of this approach is that genotypes characterized as "weak competitors" are exceptionally resilient to environmental forces that induce acquired intra-crop variation and, thus, could be employed to optimize resource use at crop level, while, at the same time, efficiency in resource use at single-plant level promotes stability due to better overall results in case of missing plants in the field [50].…”

Peasant Seeds in France: Fostering A More Resilient Agriculture

“…The comparative yield of landraces and commercial varieties is the subject of controversy. Nonetheless, it is generally acknowledged that landraces typically lag behind commercial varieties in terms of profitability [46]. Peasant seeds' lower productivity is partly explained by the fact that genetic richness augments intra-specie competition, which negatively affect output [47].…”