Bread Wheat Landraces Adaptability to Low-Input Agriculture.

Bread wheat landraces were an important source of biodiversity used in agriculture before the widespread adoption of high-yielding commercial cultivars adapted to high inputs. Could future agriculture exploit these landraces in different cropping systems in organic or lower-input environments? A two-year field trial was conducted to evaluate grain yield, agronomic performance, and grain quality of bread wheat landraces under different cropping systems, including low-input/organic/conventional environments. Significant variability was found for almost all characteristics among landraces, which makes landraces valuable sources of genetic variation for breeding programs aimed at achieving high and consistent production as well as high-quality products in low-input/organic environments. Additionally, landraces play a crucial role in expanding the genetic diversity of cultivated bread wheat and mitigating biodiversity erosion, thereby enabling crops to better withstand the challenges of low-input/organic agriculture. The landrace "Xilokastro Lamias" had the highest yield among the landraces evaluated in the first growing season (2.65 t·ha-1) and one of the highest yields (2.52 t·ha-1) of all genotypes in the second growing season, which shows promising potential as a starting material in breeding programs targeting high and stable yields. GGE biplot analysis identified the landrace "Xilokastro Lamias", along with commercial cultivars "Yecora E" and "Panifor", as suitable candidates for direct use in low-input/organic wheat farming systems to achieve enhanced productivity. In the conventional environment (C2-IPGRB), commercial cultivars showed the highest values (3.09 to 3.41 ton·ha-1). Of the landraces, only the X4 showed a high GY (3.10 ton·ha-1) while the other landraces had ~33-85% lower yield. In the organic environment (O2-IPGRB), the highest productivity was found in the commercial cultivar X5 and the landrace X4. Commercial cultivars X8 and X7 showed ~68% reduction in GY in the organic environment compared to the conventional, while this reduction was half for the landraces. Finally, the reduction in grain yield between conventional and organic environments was observed to be 45% for commercial cultivars, while it was only half for landraces. This finding confirms the adaptability of landraces to organic agriculture.

The Evaluation of Common Bean (Phaseolus vulgaris L.) Genotypes under Water Stress Based on Physiological and Agronomic Parameters.

Drought affects common bean productivity, and the severity of its impact is expected to increase due to climate change. The use of versatile genotypes could contribute to securing future bean production. This study investigates the adaptability of 10 common bean genotypes of indeterminate growth type under water scarcity conditions by measuring agronomic and physiological parameters. The evaluation occurs under irrigation treatments applied at two different phenological stages (anthesis (WDA) and seed filling initiation (WDSF)). The recorded adaptabilities of the genotypes (G) showed that G10 produced the highest overall seed yield in the normal irrigation (NI) (197.22 g plant-1) and WDA (192.78 g plant-1), while the G6 had the highest yield at WDSF (196.71 g plant-1). For the genotype's average mean, chlorophyll content decreased by 10.5% under drought at WDSF. Net photosynthetic rate (Pn), stomatal conductance (gs), and transpiration rate (E) were reduced at WDA by 53%, 80.8%, and 61.4% and at WDSF by 43.75%, 57.7%, and 36%, respectively, while relative water content (RWC) reduced by 16.48%, on average, for both stages. G10 and G6 showed adaptability when water scarcity occurred at an early (WDA) or later stage (WDSF), respectively, providing insights into using germplasm resources to cope with the drought effect.

Wheat landraces are better qualified as potential gene pools at ultraspaced rather than densely grown conditions.

The negative relationship between the yield potential of a genotype and its competitive ability may constitute an obstacle to recognize outstanding genotypes within heterogeneous populations. This issue was investigated by growing six heterogeneous wheat landraces along with a pure-line commercial cultivar under both dense and widely spaced conditions. The performance of two landraces showed a perfect match to the above relationship. Although they lagged behind the cultivar by 64 and 38% at the dense stand, the reverse was true with spaced plants where they succeeded in out-yielding the cultivar by 58 and 73%, respectively. It was concluded that dense stand might undervalue a landrace as potential gene pool in order to apply single-plant selection targeting pure-line cultivars, attributable to inability of plants representing high yielding genotypes to exhibit their capacity due to competitive disadvantage. On the other side, the yield expression of individuals is optimized when density is low enough to preclude interplant competition. Therefore, the latter condition appears ideal to identify the most promising landrace for breeding and subsequently recognize the individuals representing the most outstanding genotypes.