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The lack of a suitable rootstock to control scion growth has limited the development of high-density plantations in pear production, which is partly attributed to poor understanding of the dwarfing mechanism. In the present study, the rootstock of the dwarf-type pear (Pyrus betulaefolia) ‘PY-9’ was identified and used as the material for anatomical analysis. ‘PY-9’ grew to half the tree height of the normal cultivar ‘Zhengdu’, along with fewer internodes and shorter length. Significant differences in growth rate between ‘PY-9’ and ‘Zhengdu’ were detected at approximately 30 days after full bloom, which corresponded with the time of the greatest difference in water potential between the dwarf and normal cultivar. ‘PY-9’ showed a higher photosynthetic rate than ‘Zhengdu’. Anatomical analysis showed that ‘PY-9’ had higher area ratios of both phloem and xylem and more developed vascular tissues than ‘Zhengdu’. The three-dimensional reconstructed skeleton of the xylem from X-ray computed tomography scanning revealed greater intervessel connectivity in ‘Zhengdu’ than in ‘PY-9’, which could contribute to the more vigorous growth of ‘Zhengdu’. This study thus provides the first comparison of the microstructural properties of xylem elements between a dwarfing-type and vigorous-type pear rootstock, providing new insights into the dwarfing mechanism in pear and facilitating breeding of dwarf pear rootstocks to increase crop productivity.

Iron slag, a byproduct of the wet zinc refining process, contains a substantial amount of valuable metals such as iron and zinc, making it highly valuable for comprehensive recovery and reuse. However, before recovery, the iron slag requires dehydration pretreatment. The water content in iron slag remains relatively high and difficult to remove even after pressure filtration, leading to extended drying times, reduced drying efficiency, and increased energy consumption. This study explores a novel ultrasonic pretreatment process for iron slag. Using the response surface methodology, we investigated the effects of ultrasonic power, ultrasonic time, liquid-to-solid ratio, and their interactions on the water content, capillary suction time (CST), and filtration resistance of the slag. Regression equations were established to predict the relationships between the water content, CST, filtration resistance, and the various factors. The optimal process parameters were determined as an ultrasonic power of 60 W, ultrasonic time of 22 s, and a liquid-to-solid ratio of 4:1. Under these conditions, the dehydration performance of the iron slag was optimal. The measured values closely matched the predicted values, demonstrating the reliability of the model and the feasibility of the optimized process. Our study of the mechanism of ultrasonic action on iron slag found that under the influence of ultrasonic waves, the particle size of the slag significantly decreased, and the particle morphology changed. Compared to conventional drying, the drying rate of the iron slag after ultrasonic pretreatment was accelerated, and the drying time was reduced.

The lotus (Nelumbo Adans.) is one of the most economically relevant ornamental aquatic plants. Plant architecture (PA) is an important trait for lotus classification, cultivation, breeding, and applications. However, the underlying genetic and molecular basis controlling PA remains poorly understood. In this study, an association study for PA-related traits was performed with 93 genome-wide microsatellite markers (simple sequence repeat, SSR) and 51 insertion–deletion (InDel) markers derived from the candidate regions using a panel of 293 lotus accessions. Phenotypic data analysis of the five PA-related traits revealed a wide normal distribution and high heritability from 2013 to 2016, which indicated that lotus PA-related traits are highly polygenic traits. The population structure (Q-matrix) and the relative kinships (K-matrix) of the association panels were analyzed using 93 SSR markers. The mixed linear model (MLM) taking Q-matrix and K-matrix into account was used to estimate the association between markers and the traits. A total of 26 markers and 65 marker–trait associations were identified by considering associations with p < 0.001 and Q < 0.05. Based on the significant markers, two QTLs on Chromosome 1 were identified, and two candidate genes were preliminarily determined. The results of our study provided useful information for the lotus breeding aiming at different PA phenotypes using a molecular-assisted selection (MAS) method and also laid the foundation for the illustration of the molecular mechanism underlying the major QTL and key markers associated with lotus PA.

Hedgehog (Hh) signaling patterns embryonic tissues and contributes to homeostasis in adults. In Drosophila, Hh transport and signaling are thought to occur along a specialized class of actin-rich filopodia, termed cytonemes. Here, we report that Interference hedgehog (Ihog) not only forms a Hh receptor complex with Patched to mediate intracellular signaling, but Ihog also engages in trans-homophilic binding leading to cytoneme stabilization in a manner independent of its role as the Hh receptor. Both functions of Ihog (trans-homophilic binding for cytoneme stabilization and Hh binding for ligand sensing) involve a heparin-binding site on the first fibronectin repeat of the extracellular domain. Thus, the Ihog-Ihog interaction and the Hh-Ihog interaction cannot occur simultaneously for a single Ihog molecule. By combining experimental data and mathematical modeling, we determined that Hh-Ihog heterophilic interaction dominates and Hh can disrupt and displace Ihog molecules involved in trans-homophilic binding. Consequently, we proposed that the weaker Ihog-Ihog trans interaction promotes and stabilizes direct membrane contacts along cytonemes and that, as the cytoneme encounters secreted Hh ligands, the ligands trigger release of Ihog from trans Ihog-Ihog complex enabling transport or internalization of the Hh ligand-Ihog-Patched -receptor complex. Thus, the seemingly incompatible functions of Ihog in homophilic adhesion and ligand binding cooperate to assist Hh transport and reception along the cytonemes.