Precise estimation of sediment transport capacity (Tc) is critical to the development of physically based erosion models. Few data are available for estimating Tc on steep slopes. The objectives of this study were to evaluate the effects of unit flow discharge (q), slope gradient (S), and mean flow velocity on Tc in shallow flows and to investigate the relationship between Tc and shear stress, stream power, and unit stream power on steep slopes using a 5‐m‐long and 0.4‐m‐wide nonerodible flume bed. Unit flow discharge ranged from 0.625 × 10−3 to 5 × 10−3 m2 s−1 and slope gradient from 8.8 to 46.6%. The diameter of the test riverbed sediment varied from 20 to 2000 μm, with a median diameter of 280 μm. The results showed that Tc increased as a power function with discharge and slope gradient with a coefficient of Nash–Sutcliffe model efficiency (NSE) of 0.95. The influences of S on Tc increased as S increased, with Tc being slightly more sensitive to q than to S The Tc was well predicted by shear stress (NSE = 0.97) and stream power (NSE = 0.98) but less satisfactorily by unit stream power (NSE = 0.92) for the slope range of 8.8 to 46.6%. Mean flow velocity was also a good predictor of Tc (NSE = 0.95). Mean flow velocity increased as q and S increased in this study. Overall, stream power seems to be the preferred predictor for estimating Tc for steep slopes; however, the predictive relationships derived in this study need to be evaluated further in eroding beds using a range of soil materials under various slopes.

BackgroundBrassica oleracea encompass a family of vegetables and cabbage that are among the most widely cultivated crops. In 2009, the B. oleracea Genome Sequencing Project was launched using next generation sequencing technology. None of the available maps were detailed enough to anchor the sequence scaffolds for the Genome Sequencing Project. This report describes the development of a large number of SSR and SNP markers from the whole genome shotgun sequence data of B. oleracea, and the construction of a high-density genetic linkage map using a double haploid mapping population.ResultsThe B. oleracea high-density genetic linkage map that was constructed includes 1,227 markers in nine linkage groups spanning a total of 1197.9 cM with an average of 0.98 cM between adjacent loci. There were 602 SSR markers and 625 SNP markers on the map. The chromosome with the highest number of markers (186) was C03, and the chromosome with smallest number of markers (99) was C09.ConclusionsThis first high-density map allowed the assembled scaffolds to be anchored to pseudochromosomes. The map also provides useful information for positional cloning, molecular breeding, and integration of information of genes and traits in B. oleracea. All the markers on the map will be transferable and could be used for the construction of other genetic maps.

No abstract

No abstract