Tough hydrogels that are capable of efficient mechanical energy dissipation and withstanding large strains have potential applications in diverse areas. However, most reported fabrication strategies are performed in multiple steps with long-time UV irradiation or heating at high temperatures, limiting their biological and industrial applications. Hydrogels formed with a single pair of mechanisms are unstable in harsh conditions. Here we report a one-step, biocompatible, straightforward and general strategy to prepare tough soft hydrogels in a few tens of seconds under mild conditions. With a multimechanism design, the network structures remarkably improve the mechanical properties of hydrogels and maintain their high toughness in various environments. The broad compatibility of the proposed method with a spectrum of printing technologies makes it suitable for potential applications requiring high-resolution patterns/structures. This strategy opens horizons to inspire the design and application of high-performance hydrogels in fields of material chemistry, tissue engineering, and flexible electronics.

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Monitoring the pathogenic fungus of wheat stripe rust, Puccinia striiformis f. sp. tritici, plays a key role in effective control of the disease. In the present study, we developed a specific and sensitive polymerase chain reaction (PCR) assay for detecting the pathogen in wheat (Triticum aestivum) leaves. A pair of primers (PSF and PSR) was designed based on the internal transcribed spacer (ITS) region sequence of P. striiformis f. sp. tritici. PCR products that were amplified with universal primers ITS1 and ITS4 were cloned into pGEM-T Easy vectors and sequenced. The ITS sequence was compared with those of P. striiformis f. sp. tritici, P. triticina, P. graminis f. sp. tritici, Blumeria graminis f. sp. tritici, Fusarium graminearum, Rhizoctonia cerealis, and Bipolaris sorokiniana, which are associated with early symptoms of foliar diseases on wheat. Specificity of the primers was tested in the PCR assays using DNA extracted from all tested P. striiformis f. sp. tritici isolates, other fungal species, and healthy and infected wheat leaves sampled around stripe rust foci in wheat fields, different days after inoculation with P. striiformis f. sp. tritici, as well as asymptomatic wheat leaves sampled around stripe rust foci in the fields. A PCR product of 169 bp was amplified from DNA of all P. striiformis f. sp. tritici isolates. The primers did not amplify DNA from the other tested fungal species. The pathogen was detected from asymptomatic wheat leaves inoculated with P. striiformis f. sp. tritici under greenhouse conditions, as well as leaves sampled around stripe rust foci in wheat fields. Under optimum conditions, the PCR assay was highly sensitive and required only 0.1 pg of the target DNA for a detectable and reliable amplification with the PSF and PSR primers.

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Crown rot (CR) and Fusarium head blight (FHB) are two serious wheat diseases caused by Fusarium pathogens in China. To identify new resistant sources for CR and FHB, 205 Chinese wheat cultivars collected from Huang-Huai wheat-growing region in China were screened for resistance. Cunmai633, LS4607, Pubing01, and Hongyun2 showed seedling resistance to CR with disease index (DI) less than 0.25. Sixteen cultivars showed adult-plant resistance to CR with DI lower than 0.10. Twenty-six cultivars showed moderate resistance to CR at seedling stage with DI from 0.26 to 0.35, and 63 cultivars showed moderate adult-plant resistance with DI from 0.11 to 0.20. Among them, Cunmai633, LS4607, Pubing01, Xinong916, Zhengda161, Xumai14017, Zhengpinmai30, Bainong8822, Jimai216, Huacheng865, Fengyumai5, and Tianmin319 showed resistance or moderate resistance to CR at both seedling and adult plant stages, with Cunmai633 showing the best resistance. Most of the cultivars (>76%) were susceptible to FHB in both the 2017 and 2018 experiments with DI > 0.40. However, some cultivars demonstrated excellent FHB resistance. For example, Zhongyu1526, Tianminxiaoyan369, and Yangao168 were resistant (DI ≤ 0.25) in 2017 and moderately resistant (0.26 ≤ DI ≤ 0.40) in 2018; Zhongwo9 was moderately resistant in 2017 (DI = 0.38) and resistant in 2018 (DI = 0.25). Eight cultivars (Cunmai608, Zhengmai162, Minfeng266, Junda159, LS4607, Deyan1603, Pumai1165, and Fengmai12) showed moderate FHB resistance with DI lower than 0.40 in both experiments. LS4607 showed moderate resistance to both diseases. The resistant cultivars identified in this study can be used for mapping the resistance genes and improving resistance to CR and/or FHB.