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[Objective] This study comprehensively evaluated the drought tolerance of watermelon resources by screening drought tolerant germplasm resources and identifying key drought tolerance indexes at seedling stage to provide support for drought tolerance breeding of watermelon. [Method] Twenty-five watermelon materials were selected for two treatments of drought stress and normal watering in pots at seedling stage. Seven growth indexes including plant height, root length, aboveground fresh weight, underground fresh weight, aboveground dry weight, underground dry weight and root-shoot ratio, and six physiological indexes including chlorophyll content, soluble protein content, proline content, nialondialdehyde con-tent, catalase activity and relative conductivity were measured. Using the methods of membership function, multiple linear regression analysis and cluster analysis, the response differences of watermelon gerniplasm to drought stress were compared, the drought resistance of gerniplasm at seedling stage was evaluated, and the key drought resistance indexes were screened. [Result] Drought stress inhibited the growth and development of watermelon seedlings. Drought stress significantly inhibited shoot fresh mass and root fresh mass of watermelon seedlings, generally reduced plant height, root length, shoot dry mass and root dry mass, and had positive and negative effects on root-shoot ratio. After drought treatment, proline content in watermelon leaves increased significantly, catalase activity increased generally, soluble protein content and relative conductivity in leaves decreased generally, while chlorophyll and nialondialdehyde contents showed differences among germplasms. [Conclusion] The watermelon materials with strong drought resistance at seedling stage including M20, ZTC, M33, M24 and M26, and they can be used for further breeding watermelon resources with drought resistance. Shoot fresh weight, catalase activity, soluble protein content, pro-line content, underground dry weight, and root length could be used as the traits for evaluating drought resistance of watermelon seedlings. [ABSTRACT FROM AUTHOR]

The synthesis of gram quantities of the TF antigen (β-ᴅ-Gal-(1→3)-α-ᴅ-GalNAc) and its 3'-sulfated analogue with a TEG-N 3 spacer attached is described. The synthesis of the TF antigen comprises seven steps, from a known N -Troc-protected galactosamine donor, with an overall yield of 31%. Both the spacer (85%) and the galactose moiety (79%) were introduced using thioglycoside donors in NIS/AgOTf-promoted glycosylation reactions. The 3'-sulfate was finally introduced through tin activation in benzene/DMF followed by treatment with a sulfur trioxide-trimethylamine complex in a 66% yield., (Copyright © 2024, Reihill et al.)