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[Objective] The study aims to explore the physiological mechanism of different grafting patterns in alleviating the low temperature stress of melon (Cucumis melo L.) seedlings, in order to provide a theoretical basis for selecting appropriate grafting patterns to improve the resistance of melon to low temperature. [Methods] Taking the thick and thin skin melon varieties as scions, respectively, and the white seed pumpkin as a rootstock, with the self-rooted melon seedling as control, the effects of double root, adhering, and attaching grafting patterns on the photosynthetic pigment content, photosynthetic gas exchange parameters, cell membrane permeability, and antioxidant enzyme activity of leaves of melon seedlings were studied under three treatments, including before low temperature (15 ℃/10 ℃), low temperature, and after low temperature treatment (rewarming treatment). [Results] (1) The photosynthetic pigment content and photosynthetic gas exchange parameters of leaves of the grafted seedlings of various melon varieties were decreased under low temperature treatment; these physiological parameters were increased after rewarming treatment, among which the attaching grafted seedling had the lowest decrease and the highest increase. (2) The relative conductivity, malondialdehyde content, hydrogen peroxide content, and superoxide anion production rate in leaves of the grafted seedlings of all melon varieties were increased under low temperature treatment, and were decreased under rewarming treatment, among which the attaching grafted seedlings had the lowest increase and the highest decrease. (3) The activities of superoxide dismutase, peroxidase, and catalase in leaves of the grafted seedlings of all melon varieties were increased under low temperature, and were increased under rewarming treatment, and the attaching grafted seedlings had the most significant increase. [Conclusion] The three grafting patterns enhance the activities of antioxidant enzymes of thick-skinned and thin-skinned melon seedlings under low temperature stress and rewarming, and effectively reduce the accumulation of reactive oxygen species, maintain the photosynthetic capacity of seedlings, and improve low temperature tolerance of seedlings. The attaching grafting has the best performance.

In this paper we present a comparative sustainability evaluation of a Smart Mobile Factory (SMF) and the conventional Centralized Factory (CF) for the prefabrication of components needed in linear infrastructure construction projects. The research aims to evaluate the environmental and productivity related (economic) impacts of both factory models in the context of sustainable development. The focus of the study is on comparing the logistics performance indicators and environmental sustainability aspects of both approaches. The SMF, a novel approach for distributed onsite manufacturing is compared to the traditional centralized field factory model. The assessment is based on sustainability indicators focusing on transportation cost, and carbon emissions. To offer useful insights into how the SMF and CF techniques might be applied in actual situations, a case study of the Hyperloop Construction project in Switzerland was carried out. The systems under consideration, namely the Smart Mobile Factory (SMF) and Centralized Factory for hyperloop construction, are inherently complex and hence were conceptually modelled. Following the conceptual modelling, facility location and network optimization were carried out to further understand the flow of product units between the facilities and construction sites. The supply chain analysis was performed by using AnyLogistix software. Both approaches were compared in terms of sustainability related impacts. Transportation cost and emissions were selected as the indicators to be compared. The results showed the SMF based approach to be more cost effective and produces lesser carbon emissions than the CF based approach. In the future, the work will be extended to understand the effects of supply chain disruptions on the project progress by simulating the new scenarios. [ABSTRACT FROM AUTHOR]

In this paper, the effect of Na+ concentration on the crystalline phase, morphology, and content of vaterite in a system with different Ca2+ and CO32− ratios using steamed ammonia liquid waste as the calcium source was investigated, and the effect of Na+ on the yield of vaterite was studied systematically for the first time. The obtained products were characterized by powder X-ray diffraction (XRPD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, laser particle size analysis (LPSA), and so on. The results show that the variation of Na+ concentration in different Ca2+ and CO32− ratio systems has an effect on the particle size, morphology, content, and CaCO3 yield of vaterite. Thermogravimetric (TG) analysis indicates that Na+ is involved in forming CaCO3 but does not enter the interior of the vaterite crystals. Mechanistic analysis shows that changes in Na+ concentration can alter the initial pH of the reaction system and the conductivity of the solution, thus changing the processes such as early nucleation and crystal growth of vaterite as well as inhibiting the vaterite phase transition, which determines the particle size of the vaterite obtained. This study reveals to a certain extent the influence of Na+ on the early nucleation and crystal growth of vaterite and provides theoretical support for the realization of large-scale industrial production of vaterite. [ABSTRACT FROM AUTHOR]

Watermelon is a crucial horticultural crop worldwide but its genetic base has become extremely narrow owing to long-term cultivation. Induced mutagenesis can create a range of variations with distinctive agricultural characteristics. To broaden the genetic diversity of watermelon, we established a mutagenesis library containing over 4000 M1 seeds from an inbred line 'M08', which was irradiated by 350 Gy of 60Co γ-rays for 3 h. The rates of germination, emergence, and survival of the M1 seeds were reduced by 5.88%, 18.66%, and 41.96%, respectively. After phenotypic screening, 20 and 10 types of morphological changes were observed in the M1 and M2 generations, with approximately 10.57% and 14.17% mutation frequencies, respectively. Six mutants with desirable horticultural alterations were selected for additional presentation, including the leaf color mutant C1-NO.1, the yellow peel mutant C1-NO.2, the pericarp thickening mutant C1-NO.3, the pericarp thinning mutant C1-NO.4, the seedless mutant C1-NO.5, and the C2-No.1 mutant with normal female flowers and malformed male flowers. Moreover, the three mutants M1-3, M2-1, and M1-5 were identified from our EMS-induced M2 library, exhibiting the fusiform fruit, the dark green peel, and the yellow leaves, respectively. Compared to the wild type (WT), the photosynthetic pigments and parameters were negatively impacted in the yellow-leaf mutant M1-5. For example, the total chlorophyll was 1.22 and 2.22 mg/g in the young and mature leaves of M1-5, respectively, which were significantly lower than those in the WT (2.58 and 2.90 mg/g, respectively). Notably, some mutagenesis phenotypes could be stably inherited, including traits such as yellow leaf color, fusiform fruit shape, and thickening and thinning pericarp. Taken together, these results indicate that these two mutant libraries serve as essential resources to discover new phenotypic germplasms, thereby facilitating the genetic breeding and functional gene exploration in watermelon. [ABSTRACT FROM AUTHOR]

Precocious leaf senescence can reduce crop yield and quality by limiting the growth stage. Melatonin has been shown to delay leaf senescence; however, the underlying mechanism remains obscure. Here, we show that melatonin offsets abscisic acid (ABA) to protect photosystem II and delay the senescence of attached old leaves under the light. Melatonin induced H2O2 accumulation accompanied by an upregulation of melon respiratory burst oxidase homolog D (CmRBOHD) under ABA‐induced stress. Both melatonin and H2O2 induced the accumulation of cytoplasmic‐free Ca2+ ([Ca2+]cyt) in response to ABA, while blocking of Ca2+ influx channels attenuated melatonin‐ and H2O2‐induced ABA tolerance. CmRBOHD overexpression induced [Ca2+]cyt accumulation and delayed leaf senescence, whereas deletion of Arabidopsis AtRBOHD, a homologous gene of CmRBOHD, compromised the melatonin‐induced [Ca2+]cyt accumulation and delay of leaf senescence in Arabidopsis under ABA stress. Furthermore, melatonin, H2O2 and Ca2+ attenuated ABA‐induced K+ efflux and subsequent cell death. CmRBOHD overexpression and AtRBOHD deletion alleviated and aggravated the ABA‐induced K+ efflux, respectively. Taken together, our study unveils a new mechanism by which melatonin offsets ABA action to delay leaf senescence via RBOHD‐dependent H2O2 production that triggers [Ca2+]cyt accumulation and subsequently inhibits K+ efflux and delays cell death/leaf senescence in response to ABA. Summary statement: Melatonin has been shown to delay leaf senescence; however, the underlying mechanism remains obscure. This study shows that melatonin counteracts abscisic acid (ABA) to delay leaf senescence via RBOHD‐dependent H2O2 production that triggers cytoplasmic‐free Ca2+ accumulation and subsequently inhibits K+ efflux and delays cell death in response to ABA. [ABSTRACT FROM AUTHOR]