Search Results (25)

Overlying hard and thick igneous rocks pose numerous potential safety hazards during the exploitation of coal resources. Identifying the spatial distribution of igneous rocks and analyzing their impact on coal mining are a primary research concern. In this study, a coal mine was investigated in depth. Initially, based on the seismic information, the authors predicted the occurrence conditions of igneous rocks in coal measure strata. Subsequently, two models were developed via the UDEC software4.00: one with igneous layers and the other without. Using the simulation results, the change law of stress, the roof abscission layer, and roof strata subsidence in the overburden during coal face advancement were analyzed. Through a comparison of the simulation results, the hazard-causing mechanism of the igneous intrusion was discussed. Consequently, the occurrence of igneous rocks in the overburden is crucial for predicting potential safety hazards, and the seismic inversion method can be considered an effective tool for evaluating overlying igneous strata. Full article

Apples are widely cultivated primarily for fresh consumption. During mechanized harvesting, the extraction of fruit stalks can significantly impact the storage duration of fresh apples. The tensile force applied to the abscission layers is a critical factor in retaining the stalks; yet, few researchers have focused on preventing stalk pull-out during picking. In this research, we studied the phenomenon of missing stalks during mechanical picking by analyzing the tensile force exerted on the abscission layer during picking and optimizing the attitude of the end effector to achieve the highest stalk retention rate. Firstly, the tangential and normal energy release rates of the abscission layer were used as key parameters to model the cohesive zone of the abscission layer, a finite element model of the fruit–stalk–branch system was developed, based on which the actual fruit picking process using direct-pulling and twisting was simulated. Subsequently, the data obtained from the simulation were analyzed using response surface analysis, and the maximum tensile force at the time of fracture of the delamination and the time of its fracture were used as optimization parameters to find the optimal solution of the angle, direct-pulling speed, and twisting speed d to achieve the highest stalk retention rate. Finally, through field experiments, it was demonstrated that the optimal picking conditions could effectively improve the picking success rate and stalk retention rate. The results show that, when the end effector picks close to the fruit at about 58°, the stalk retention rate can reach 94.0%. Full article

Korla fragrant pear is a high-quality local pear variety native to Xinjiang, China. Currently, the low fruit-setting rate and low calyx shedding rate problems in Korla fragrant pears have been highlighted, which seriously affect the fruit yield and quality. It is of great significance to research the fruiting characteristics and molecular-assisted identification of Korla fragrant pear bud mutation materials for enriching the germplasm resources of Korla fragrant pear. In this research, a natural pollination group (YB) of Korla fragrant pear bud mutation materials and a natural pollination group (CK) of Korla fragrant pears were established. On the fruiting characteristics, the fruit-setting rate and calyx-removal rate of the two groups were investigated. In terms of fruit quality, the fruit shape index, fruit specific gravity, soluble solids content, sugar:acid ratio, soluble sugar content, and other indicators were measured. For the anatomical structure of the calyx tube, the detachment cells were observed. The formation time of the two groups of detached cells was compared. In the GBS simplified genome sequencing, a phylogenetic tree was constructed based on the obtained SNP sites. A principal component analysis, population genetic structure analysis, and genetic diversity index analysis were carried out. In the aspect of SSR molecular marker identification, the SSR types were counted. Polyacrylamide gel electrophoresis was performed. The results demonstrate the following: (1) the fruit-setting rate (30.87%) and calyx-removal rate (68.11%) in the YB group were significantly higher than those in the CK group (19.37%) and the calyx-removal rate (55.18%). (2) There was no significant difference in fruit quality indexes, such as average fruit weight (127.10–130.00 g) and soluble sugar content (9.47–9.56%) between the two groups. (3) Abscission-layer cells were observed at 2, 4, 6, 8, and 10 h after calyx tube discoloration in the YB group and at 48, 72, and 96 h after calyx tube discoloration in the CK group. (4) The genetic background of the YB group and the CK group was similar at the GBS level, but there were differences at the DNA level. This research finally shows that Korla fragrant pear bud mutation material is a good germplasm resource. This germplasm resource can promote the structural optimization of Korla fragrant pear varieties and the healthy development of the industry. Full article

Programmed cell death (PCD) is common in plant growth and development, such as xylem development, organ senescence, and abscission. Calyx abscission in Korla fragrant pear contributes to fruit quality, while it was not clear whether PCD occurred during calyx abscission and which signals regulated the process. Therefore, it is imperative to clarify the process of PCD in the process of calyx abscission in Korla fragrant pear under natural conditions to enrich the mechanism of calyx abscission. The results showed that the total time of calyx abscission of Korla fragrant pear began from 6 days after pollination (DAP) to 13 DAP, and the peak of calyx abscission occurred 10 DAP. During the whole process of calyx abscission, PCD started 6 DAP. At 9 DAP, the degree of PCD deepened. At 12 DAP, the cells in the abscission zone showed asymmetry on both sides, the organelles in the distal cells of the abscission zone degraded into apoptotic fragments, and the protective layer of the normal development of cells located at the proximal end of the abscission zone region ended the PCD process. ETH concentrations in the abscission zone of the decalyx fruit were significantly higher than those of the persistent calyx fruits in each period during calyx abscission, and high levels of ethylene and hydrogen peroxide and low contents of the GA₃, ZT, and hydroxyl radicals promoted calyx abscission before the formation of the abscission zone. At 3 DAP, the ethylene concentration (43.97 ppm) and H₂O₂ content (8.49 μmol/g) of decalyx fruit in the abscission zone were significantly higher than those of persistent calyx fruit by 67.69% and 27.86%, respectively; however, the GA₃, ZT, and hydroxyl radicals showed the opposite. Overall, PCD in the abscission zone of decalyx fruits did occur during the calyx abscission of Korla fragrant pear, and ethylene and H₂O₂ might play major roles in initiating the PCD process during Korla fragrant pear calyx abscission. Full article

In recent years, the deformation detection technology for underground tunnels has played a crucial role in coal mine safety management. Currently, traditional methods such as the cross method and those employing the roof abscission layer monitoring instrument are primarily used for tunnel deformation detection in coal mines. With the advancement of photogrammetric methods, three-dimensional laser scanners have gradually become the primary method for deformation detection of coal mine tunnels. However, due to the high-risk confined spaces and distant distribution of coal mine tunnels, stationary three-dimensional laser scanning technology requires a significant amount of labor and time, posing certain operational risks. Currently, mobile laser scanning has become a popular method for coal mine tunnel deformation detection. This paper proposes a method for detecting point cloud deformation of underground coal mine tunnels based on a handheld three-dimensional laser scanner. This method utilizes SLAM laser radar to obtain complete point cloud information of the entire tunnel, while projecting the three-dimensional point cloud onto different planes to obtain the coordinates of the tunnel centerline. By using the calculated tunnel centerline, the three-dimensional point cloud data collected at different times are matched to the same coordinate system, and then the tunnel deformation parameters are analyzed separately from the global and cross-sectional perspectives. Through on-site collection of tunnel data, this paper verifies the feasibility of the algorithm and compares it with other centerline fitting and point cloud registration algorithms, demonstrating higher accuracy and meeting practical needs. Full article

The nutritional value of blue honeysuckle (Lonicera caerulea L.) fruit is abundant; however, its production faces challenges due to a short harvesting period and fruit drop issues. In this study, the effects and potential mechanisms of two different plant growth regulators, GA₃ (Gibberellins acid) and 2,4-D (2,4-Dichlorophenoxyacetic acid), on blue honeysuckle fruit abscission and abscission layer formation were investigated. The main cultivated variety of blue honeysuckle, ‘Berel’, was used as the experimental material. GA₃ and 2,4-D were sprayed on the plants from the veraison. The anatomical structure of the fruit abscission zone (FAZ) was observed after treatment. Key enzymes involved in cell wall degradation, pectinase, cellulase, polygalacturonase, and pectin methylesterase, were analyzed for their activities. Furthermore, the gene expression levels of cell wall detachment-related genes CX1, CX2, PL20, PE, and key genes for gibberellin and ethylene synthesis GA2OX1, GA1, ACO, and ACO3 were examined. The results indicated that the application of GA₃ and 2,4-D could delay the formation of the abscission layer. In the FAZ treated with GA₃ and 2,4-D at 5 DAT, the activity of key enzymes involved in cell wall degradation decreased, the expression of genes related to cell wall degradation enzymes and key genes for ethylene synthesis was inhibited, and the drop of fruit reduced. In conclusion, exogenous application of GA₃ and 2,4-D suppresses the abscission of ‘Berel’ blue honeysuckle fruit, likely through the inhibition of cell wall degradation and abscission layer formation. Full article

A collection of 30 melon introgression lines (ILs) was developed from the wild accession Ames 24297 (TRI) into ‘Piel de Sapo’ (PS) genetic background. Each IL carried an average of 1.4 introgressions from TRI, and the introgressions represented 91.4% of the TRI genome. Twenty-two ILs, representing 75% of the TRI genome, were evaluated in greenhouse (Algarrobo and Meliana) and field (Alcàsser) trials, mainly to study traits related to domestication syndrome such as fruit weight (FW) and flesh content (FFP), as well as other fruit quality traits as fruit shape (FS), flesh firmness (FF), soluble solid concentration (SSC), rind color and abscission layer. The IL collection showed an impressive variation in size-related traits, with FW ranging from 800 to 4100 g, reflecting the strong effect of the wild genome on these traits. Most of the ILs produced smaller fruits compared with PS; however, unexpectedly, the IL TRI05-2 produced bigger fruits, likely due to new epistatic interacions with the PS genetic background. In contrast, the genotypic effect for FS was smaller, and few QTLs with notable effects were detected. Interestingly, variability was also observed for FFP, FF and SSC, rind color and abscission layer formation. Genes in these introgressions are candidates for having been involved in melon domestication and diversification as well. These results confirm that the TRI IL collection is a very powerful tool for mapping traits of agronomic interest in melon, allowing the confirmation of previously reported QTLs and the identification of new ones to better understand the domestication process of this crop. Full article

Seed shattering is an important trait that wild rice uses to adapt to the natural environment and maintain population reproduction, and weedy rice also uses it to compete with the rice crop. The loss of shattering is a key event in rice domestication. The degree of shattering is not only one of the main reasons for rice yield reduction but also affects its adaptability to modern mechanical harvesting methods. Therefore, it is important to cultivate rice varieties with a moderate shattering degree. In this paper, the research progress on rice seed shattering in recent years is reviewed, including the physiological basis, morphological and anatomical characteristics of rice seed shattering, inheritance and QTL/gene mapping of rice seed shattering, the molecular mechanism regulating rice seed shattering, the application of seed-shattering genes, and the relationship between seed-shattering genes and domestication. Full article

In this paper, mechanical stirring and ultrasonic treatment are used to separate graphite electrode materials from copper foils in recycling spent lithium-ion batteries (LIBs). Firstly, the effects of ultrasonic power (60–180 W), ultrasonic time (1–8 min), stirring speed (420–2000 rpm), and stirring time (1–8 min) on the abscission rate of active material on copper foil were studied. It was found that the peeling-off ratio of electrode material under ultrasonic treatment was 91.34% compared with stirring treatment (84.22%). The removal of electrode material from copper foil during stirring was mainly through mechanical scrubbing. As a comparison, the generation of the microjets induced by ultrasound, the local high-temperature and high-pressure environment, and the free radicals during ultrasonic treatment are the key factors to further improve electrode material removal efficiency. An integrated ultrasound-mechanical stirrer technique can achieve a high-efficient separation performance (approximately 100% peeling-off ratio) of anode electrode materials from copper foils. The effects of mechanical stirring speed, temperature, and treatment time on the peeling-off ratios of the ultrasound-mechanical stirrer-assisted system were investigated. Finally, the results of XRF (X-ray fluorescence spectrometer), XRD (X-ray diffraction), and SEM-EDS (scanning electron microscopy coupled with energy dispersive X-ray spectroscopy) showed that the as-separated graphite electrode material had high purity and contained almost no copper foil impurities. Numerical simulation analyses briefly showed that the difference between pressure and ultrasonic temperature changes in the boundary between different anode layers (graphite on copper foil in aqueous solution) was the main effective factor in the considerable separation of graphite from copper anode foil under ultrasonic-assisted delamination. Full article

Crystals in the fruits of Apiaceae are of great importance for taxonomy. The presence/absence and location of large prismatic crystals, druses, and spherical aggregates characterize genera, tribes, and subfamilies. When the fruits of Apiaceae split into mericarps, cell separation occurs, and probably cell death and the destruction of their walls. In clades Saniculeae and Scandicinae, this process is accompanied by the accumulation of calcium oxalate crystals in the abscission layer. However, reports of smaller crystals are rare, and their taxonomic significance is unknown. To fill this gap, we started research with four species of the clade Apieae: Ammi majus, Modesciadium involucratum, Deverra aphylla, and Rutheopsis tortuosa; in the last two species, crystals were described for the first time. We also studied crystals in Chaerophyllum bulbosum from the clade Scandicinae, and in Sanicula rubriflora from the clade Saniculeae. Conventional optical and polarizing microscopy, scanning electron microscopy, and energy dispersive spectroscopy (EDS) were used. In the clade Apieae, the studied species contained crystals in the exocarp and on the commissure, and often in the mesocarp parenchyma as well; the shapes of the crystals are small druses and crystal sand. The calcium content in the crystals was determined as 10–31%; crystals contain also carbon and oxygen and are most likely composed of calcium oxalate. In the fruits of Apiaceae studied, the silicon content is low (<0.3%). Full article

This paper aims to provide the basis of the parameters and data interpretation for some important problems, such as the identification of the type of overlying strata and the analytical calculation, where the coal mine is employed as the object of the study. Particularly, the rock structure and fracture development characteristics of the overlying strata were observed, and the development conditions of the fracture zone were counted. By utilizing the on-site stress data, the inclination of the broken zone based on the rock fracture theory was calculated. The study shows that the distribution of the mining fissure is related to the rock and integrity degree of the strata, and that the native maximum expansion angle of fissure is 70.54°. With mining influence, small angle native shallow fissures will be bound to expansion, and the deep-mined fissure extension will be developed in the same direction. Moreover, it is easy to form the abscission layer, and then eventually form the fracture zone. The research results of this paper will not only provide an important foundation for the engineering practice, but also benefit the study of the simultaneous extraction of coal and gas. Full article

The loss of seed shattering is an important event in crop domestication, and elucidating the genetic mechanisms underlying seed shattering can help reduce yield loss during crop production. This study is the first to systematically identify and analyse the BELL family of transcription factor-encoding genes in Chinese wild rice (Zizania latifolia). ZlqSH1a (Zla04G033720) and ZlqSH1b (Zla02G027130) were identified as key candidate genes involved in seed shattering in Z. latifolia. These genes were involved in regulating the development of the abscission layer (AL) and were located in the nucleus of the cell. Over-expression of ZlqSH1a and ZlqSH1b resulted in a complete AL between the grain and pedicel and significantly enhanced seed shattering after grain maturation in rice. Transcriptome sequencing revealed that 172 genes were differentially expressed between the wild type (WT) and the two transgenic (ZlqSH1a and ZlqSH1b over-expressing) plants. Three of the differentially expressed genes related to seed shattering were validated using qRT-PCR analysis. These results indicate that ZlqSH1a and ZlqSH1b are involved in AL development in rice grains, thereby regulating seed shattering. Our results could facilitate the genetic improvement of seed-shattering behaviour in Z. latifolia and other cereal crops. Full article

Mitigating the function of acquired transgenes in crop wild/weedy relatives can provide an ideal strategy to reduce the possible undesired environmental impacts of pollen-mediated transgene flow from genetically engineered (GE) crops. To explore a transgene mitigation system in rice, we edited the seed-shattering genes, SH4 and qSH1, using a weedy rice line (“C9”) that originally had strong seed shattering. We also analyzed seed size-related traits, the total genomic transcriptomic data, and RT-qPCR expression of the SH4 or qSH1 gene-edited and SH4/qSH1 gene-edited weedy rice lines. Substantially reduced seed shattering was observed in all gene-edited weedy rice lines. The single gene-edited weedy rice lines, either the SH4 or qSH1 gene, did not show a consistent reduction in their seed size-related traits. In addition, reduced seed shattering was closely linked with the weakness and absence of abscission layers and reduced abscisic acid (ABA). Additionally, the genes closely associated with ABA biosynthesis and signaling transduction, as well as cell-wall hydrolysis, were downregulated in all gene-edited weedy rice lines. These findings facilitate our deep insights into the underlying mechanisms of reduced seed shattering in plants in the rice genus Oryza. In addition, such a mitigating technology also has practical applications for reducing the potential adverse environmental impacts caused by transgene flow and for managing the infestation of weedy rice by acquiring the mitigator from GE rice cultivars through natural gene flow. Full article

Two studies were conducted to determine how methyl jasmonate (MeJA), jasmonic acid (JA), and 1-aminocyclopropane-1-carboxylic acid (ACC) affect grape berry abscission in the initial days after treatment. The overarching goal was to determine whether JA, with or without ACC, may hold the potential to sufficiently reduce fruit detachment force (FDF) and increase the proportion of berries with dry stem scars while minimizing preharvest abscission, effects that could be useful in the production of stemless table grapes. On Thompson Seedless grapes, JA was at least as effective as MeJA for stimulating berry abscission based on reduced fruit detachment force (FDF) and yielding detached berries with dry stem scars. Further, since previous studies showed that ACC improved MeJA-induced grape abscission, we tested ACC effects on JA activity. We found that JA rapidly induced preharvest berry abscission, confirming previous results. ACC alone did not induce preharvest berry abscission, but ACC improved the effectiveness of JA on reducing FDF and increasing dry stem scar development. These studies also demonstrated that JA-induced abscission occurs within the first day after treatment. Commercial use of JA plus ACC as an abscission agent requires that FDF sufficiently declines, and the incidence of dry stem scars increases, prior to a significant increase in fruit abscission. However, the rapid progression of fruit abscission may require harvest either within 24 and 48 h after treatment or the use of a passive catch system. Full article

The seed yield of grass species is greatly dependent on inflorescence morphological traits, starting with spikelets per inflorescence and seeds per spikelet, to kernel size, and then to awns. Previous studies have attempted to estimate the contribution of these traits on the harvested yield of major cereal crops, but little information can be accessed on the influence of awns on seed yield of forage grass species. Siberian wildrye (Elymus sibiricus L.) is a widely important perennial forage grass used to increase forage production in arid and semi-arid grasslands. The grass has long inflorescences with long awns developed at the tip end of the lemmas in the florets. In order to evaluate the effect of awns on Siberian wildrye seed production, awn excision analyses from 10 accessions were performed at flowering stage under irrigated and rainfed regimes. Overall, awn excision reduced thousand-seed weight and seed size under both irrigated and rainfed regimes, which decreased final seed yield per plant. De-awned plants produced significantly more seeds per inflorescence, but spikelets per inflorescence was not influenced by awn excision in either condition. Moreover, histological analyses showed a high degradation of the abscission layer in the awned plants than de-awned ones, and awn excision evidently improved average seed breaking tensile strength (BTS), and thus decreased the degree of seed shattering. In conclusion, the observed significant impact of awn excision on different yield-related traits mirrored the impact of awns on the performance of Siberian wildrye under diverse growing conditions. These results provide useful information for plant breeders, seed producers, and researchers to efficiently improve seed production in Siberian wildrye. Full article