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Current potato breeding approaches are hampered by several factors including costly seed tubers, tetrasomic inheritance and inbreeding depression. Genomic selection (GS) demonstrated interesting results regardless of the ploidy level, and can be harnessed to circumvent these problems. In this work, three GS models were evaluated using 50,107 informative SilicoDArT markers and 11 traits in two values for cultivation and use (VCU) potato trials. Two key breeding problems modelled included predicting the performance of (i) new and unphenotyped clones (cross-validation) and (ii) a VCU using another as training set (TS). GS models performed comparably. Cross-validation accuracy was high for D35, D45, DMW and BVAL, in ascending order. Prediction accuracies of the VCUs were highly correlated, but the best prediction was obtained for the smaller VCU using the bigger as TS. Cross-validation and VCU prediction accuracies were higher when bigger TSs were used. The findings herein indicate that GS can be attractively integrated in potato breeding, particularly in early clonal generations to predict and select for traits with low heritability which would otherwise require more testing years, environments and resources. [ABSTRACT FROM AUTHOR]

Sorghum [Sorghum bicolor (L.) Moench] yield loss due to terminal drought stress is common in semiarid regions. Stay‐green is a drought adaptation trait, and a deeper understanding of stay‐green‐associated traits is necessary for sorghum breeding. We hypothesize that the stay‐green trait in sorghum may be associated with the root architecture and transpiration rate under drought stress. The objectives were to (i) identify the relationship among stay‐green‐associated traits, (ii) compare the root system architecture and transpiration rate of stay‐green (B35 and 296B) and senescent (BTx623 and R16) genotypes under drought stress, and (iii) quantify the impacts of reproductive stage drought stress on gas exchange and grain yield of stay‐green and senescent genotypes. A series of drought experiments were conducted with these genotypes. Under drought stress, the stay‐green genotypes had an increased total root length in the top 30–60 cm (18%) and 60–90 cm of soil (45%) than the senescent genotypes. In contrast, under progressive soil drying, stay‐green genotypes had a decreased transpiration rate (9%) than senescent genotypes by an early (∼1 h) partial closure of stomata under high vapor pressure deficit conditions. The increased seed yield (43%) in stay‐green genotypes is due to an increased photosynthetic rate (30%) and individual seed size (35%) than senescent genotypes. Overall, it is concluded that stay‐green phenotypes had two distinct drought adaptive mechanisms: (i) increased root length for increased soil exploration for water and (ii) an early decrease in the transpiration rate to conserve soil moisture. Identifying genomic markers for these traits would accelerate drought‐tolerant sorghum breeding. [ABSTRACT FROM AUTHOR]