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"Ma, Xiaokai"
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A Lightweight Hybrid Detection System Based on the OpenMV Vision Module for an Embedded Transportation Vehicle
2025
Aiming at the real-time object detection requirements of the intelligent control system for laboratory item transportation in mobile embedded unmanned vehicles, this paper proposes a lightweight hybrid detection system based on the OpenMV vision module. The system adopts a two-stage detection mechanism: in long-distance scenarios (>32 cm), fast target positioning is achieved through red threshold segmentation based on the HSV(Hue, Saturation, Value) color space; when in close range (≤32 cm), it switches to a lightweight deep learning model for fine-grained recognition to reduce invalid computations. By integrating the MobileNetV2 backbone network with the FOMO (Fast Object Matching and Occlusion) object detection algorithm, the FOMO MobileNetV2 model is constructed, achieving an average classification accuracy of 94.1% on a self-built multi-dimensional dataset (including two variables of light intensity and object distance, with 820 samples), which is a 26.5% improvement over the baseline MobileNetV2. In terms of hardware, multiple functional components are integrated: OLED display, Bluetooth communication unit, ultrasonic sensor, OpenMV H7 Plus camera, and servo pan-tilt. Target tracking is realized through the PID control algorithm, and finally, the embedded terminal achieves a real-time processing performance of 55 fps. Experimental results show that the system can effectively and in real-time identify and track the detection targets set in the laboratory. The designed unmanned vehicle system provides a practical solution for the automated and low-power transportation of small items in the laboratory environment.
Journal Article
Genome-wide analysis of MADS-box genes and their expression patterns in unisexual flower development in dioecious spinach
2024
Evolution of unisexual flowers involves extreme changes in floral development. Spinach is one of the species to discern the formation and evolution of dioecy. MADS-box gene family is involved in regulation of floral organ identity and development and in many other plant developmental processes. However, there is no systematic analysis of MADS-box family genes in spinach. A comprehensive genome-wide analysis and transcriptome profiling of MADS-box genes were undertaken to understand their involvement in unisexual flower development at different stages in spinach. In total, 54 MADS-box genes found to be unevenly located across 6 chromosomes and can be divided into type I and type II genes. Twenty type I MADS-box genes are subdivided into Mα, Mβ and Mγ subgroups. While thirty-four type II
SoMADS
s consist of 3 MIKC*, and 31 MIKC
C
-type genes including sixteen floral homeotic MADS-box genes that are orthologous to the proposed Arabidopsis ABCDE model of floral organ identity determination, were identified in spinach. Gene structure, motif distribution, physiochemical properties, gene duplication and collinearity analyses for these genes are performed in detail. Promoters of both types of
SoMADS
genes contain mainly MeJA and ABA response elements. Expression profiling indicated that MIKCc genes exhibited more dynamic and intricate expression patterns compared to M-type genes and the majority of type-II genes
AP1, SVP
, and
SOC1
sub-groups showed female flower-biased expression profiles, suggesting their role in carpel development, while
PI
showed male-biased expression throughout flower developmental stages, suggesting their role in stamen development. These results provide genomic resources and insights into spinach dioecious flower development and expedite spinach improvement.
Journal Article
Genetic Mapping and Transcriptomic Analysis of Sepal-Derived Seed Shape in Spinach
by
Fatima, Mahpara
,
Ming, Ray
,
Khalid, Ehsan
in
Analysis
,
Cell cycle
,
Chromosome Mapping - methods
2025
Spinach is a beloved vegetable crop and widely cultivated worldwide. It is dioecious with male and female plants, although monoecious mutations exist. Female spinach exhibits two distinct sepal morphologies—thorn-shaped and round-shaped determine seed shape and strongly influence seed handling, mechanized sowing, and cultivar classification. To dissect the genetic basis of this trait, we developed an F2 population from contrasting parental lines and constructed a high-density linkage map with ~1615 bin markers spanning ~994.04 cm. A major 4.31 Mb genomic interval on chromosome 4, flanked by tightly linked markers, was consistently associated with sepal morphology. Transcriptome profiling across early and mature sepal developmental stages revealed significant enrichment of cell cycle-related pathways, including DNA replication, repair, mitosis, and cytokinesis. By integrating differential expression analysis with weighted gene co-expression network analysis, we identified 25 DEGs within the mapped interval, 11 of which showed strong co-expression with hub genes in trait-associated modules. Structural variation analysis further uncovered promoter and coding sequence polymorphisms in a subset of candidate genes. This study highlights 11 promising candidate genes potentially regulating sepal-derived seed morphology in spinach, rather than confirming definitive causal genes, providing valuable targets for functional validation and new insights into the genetic regulation of sepal development.
Journal Article
Signatures of selection in recently domesticated macadamia
2022
Macadamia is a high value nut crop that is recently domesticated, ideal for testing the effect of artificial selection. Here, we sequence the genome of Hawaiian cultivar ‘Kau’ and assemble into 794 Mb in 14 pseudo-chromosomes with 37,728 genes. Genome analysis reveals a whole-genome duplication event, occurred 46.8 million years ago. Gene expansions occurred in gene families involves in fatty acid biosynthesis. Gene duplication of MADS-Box transcription factors in proanthocyanidin biosynthesis are relevant for seed coat development. Genome re-sequencing of 112 accessions reveals the origin of Hawaiian cultivars from Mount Bauple in southeast Queensland in Australia. Selective sweeps are detected in macadamia cultivars, including genes involved in fatty acid biosynthesis, seed coat development, and heat stress response. Such strong effects of artificial selection in few generations reveals the genomic basis for ‘one-step operation’ for clonal crop domestication. The knowledge gained could accelerate domestication of new crops from wild species.
Macadamia is a recently domesticated nut crop. Here, the authors report the genome assembly of Hawaiian cultivar ‘Kau’ and conduct population genomic analyses to reveal the origin of Hawaiian cultivars and the genomic basis for one-step operation for the clonal crop domestication.
Journal Article
Characterization of a Saccharum spontaneum with a basic chromosome number of x = 10 provides new insights on genome evolution in genus Saccharum
by
Lin, Yujing
,
Zhuang, Meng
,
Zhao Yiyong
in
Chromosome number
,
Chromosome rearrangements
,
Chromosomes
2020
Key messageA novel tetraploid S. spontaneum with basic chromosome x = 10 was discovered, providing us insights in the origin and evolution in Saccharum species.Sugarcane (Saccharum spp., Poaceae) is a leading crop for sugar production providing 80% of the world’s sugar. However, the genetic and genomic complexities of this crop such as its high polyploidy level and highly variable chromosome numbers have significantly hindered the studies in deciphering the genomic structure and evolution of sugarcane. Here, we developed the first set of oligonucleotide (oligo)-based probes based on the S. spontaneum genome (x = 8), which can be used to simultaneously distinguish each of the 64 chromosomes of octaploid S. spontaneum SES208 (2n = 8x = 64) through fluorescence in situ hybridization (FISH). By comparative FISH assay, we confirmed the chromosomal rearrangements of S. spontaneum (x = 8) and S. officinarum (2n = 8x = 80), the main contributors of modern sugarcane cultivars. In addition, we examined a S. spontaneum accession, Np-X, with 2n = 40 chromosomes, and we found that it was a tetraploid with the unusual basic chromosome number of x = 10. Assays at the cytological and DNA levels demonstrated its close relationship with S. spontaneum with basic chromosome number x = 8 (the most common accessions in S. spontaneum), confirming its S. spontaneum identity. Population genetic structure and phylogenetic relationship analyses between Np-X and 64 S. spontaneum accessions revealed that Np-X belongs to the ancient Pan-Malaysia group, indicating a close relationship to S. spontaneum with basic chromosome number of x = 8. This finding of a tetraploid S. spontaneum with basic chromosome number of x = 10 suggested a parallel evolution path of genomes and polyploid series in S. spontaneum with different basic chromosome numbers.
Journal Article
Thermal Imaging-Based Lightweight Gesture Recognition System for Mobile Robots
by
Wang, Xinxin
,
Wang, Lijun
,
Ma, Xiaokai
in
Color imagery
,
Comparative analysis
,
Computer vision
2025
With the rapid advancement of computer vision and deep learning technologies, the accuracy and efficiency of real-time gesture recognition have significantly improved. This paper introduces a gesture-controlled robot system based on thermal imaging sensors. By replacing traditional physical button controls, this design significantly enhances the interactivity and operational convenience of human–machine interaction. First, a thermal imaging gesture dataset is collected using Python3.9. Compared to traditional RGB images, thermal imaging can better capture gesture details, especially in low-light conditions, thereby improving the robustness of gesture recognition. Subsequently, a neural network model is constructed and trained using Keras, and the model is then deployed to a microcontroller. This lightweight model design enables the gesture recognition system to operate on resource-constrained embedded devices, achieving real-time performance and high efficiency. In addition, using a standalone thermal sensor for gesture recognition avoids the complexity of multi-sensor fusion schemes, simplifies the system structure, reduces costs, and ensures real-time performance and stability. The final results demonstrate that the proposed design achieves a model test accuracy of 99.05%. In summary, through its gesture recognition capabilities—featuring high accuracy, low latency, non-contact interaction, and low-light adaptability—this design precisely meets the core demands for “convenient, safe, and natural interaction” in rehabilitation, smart homes, and elderly assistive devices, showcasing clear potential for practical scenario implementation.
Journal Article
SunUp and Sunset genomes revealed impact of particle bombardment mediated transformation and domestication history in papaya
2022
Transgenic papaya is widely publicized for controlling papaya ringspot virus. However, the impact of particle bombardment on the genome remains unknown. The transgenic SunUp and its progenitor Sunset genomes were assembled into 351.5 and 350.3 Mb in nine chromosomes, respectively. We identified a 1.64 Mb insertion containing three transgenic insertions in SunUp chromosome 5, consisting of 52 nuclear-plastid, 21 nuclear-mitochondrial and 1 nuclear genomic fragments. A 591.9 kb fragment in chromosome 5 was translocated into the 1.64 Mb insertion. We assembled a gapless 9.8 Mb hermaphrodite-specific region of the Y
h
chromosome and its 6.0 Mb X counterpart. Resequencing 86 genomes revealed three distinct groups, validating their geographic origin and breeding history. We identified 147 selective sweeps and defined the essential role of zeta-carotene desaturase in carotenoid accumulation during domestication. Our findings elucidated the impact of particle bombardment and improved our understanding of sex chromosomes and domestication to expedite papaya improvement.
Genome assemblies for the SunUp transgenic papaya and its progenitor Sunset identify three transgene-insertions in SunUp. Resequencing of 86 papaya genomes highlights the impacts of breeding and geographic origin.
Journal Article
The spinach YY genome reveals sex chromosome evolution, domestication, and introgression history of the species
by
Xu, Xindan
,
Wang, Jingjing
,
Fatima, Mahpara
in
Animal Genetics and Genomics
,
archaeology
,
Bioinformatics
2022
Background
Spinach (
Spinacia oleracea
L.) is a dioecious species with an XY sex chromosome system, but its Y chromosome has not been fully characterized. Our knowledge about the history of its domestication and improvement remains limited.
Results
A high-quality YY genome of spinach is assembled into 952 Mb in six pseudo-chromosomes. By a combination of genetic mapping, Genome-Wide Association Studies, and genomic analysis, we characterize a 17.42-Mb sex determination region (SDR) on chromosome 1. The sex chromosomes of spinach evolved when an insertion containing sex determination genes occurred, followed by a large genomic inversion about 1.98 Mya. A subsequent burst of SDR-specific repeats (0.1–0.15 Mya) explains the large size of this SDR. We identify a Y-specific gene,
NRT1/PTR 6.4
which resides in this insertion, as a strong candidate for the sex determination or differentiation factor. Resequencing of 112 spinach genomes reveals a severe domestication bottleneck approximately 10.87 Kya, which dates the domestication of spinach 7000 years earlier than the archeological record. We demonstrate that a strong selection signal associated with internode elongation and leaf area expansion is associated with domestication of edibility traits in spinach. We find that several strong genomic introgressions from the wild species
Spinacia turkestanica
and
Spinacia tetrandra
harbor desirable alleles of genes related to downy mildew resistance, frost resistance, leaf morphology, and flowering-time shift, which likely contribute to spinach improvement.
Conclusions
Analysis of the YY genome uncovers evolutionary forces shaping nascent sex chromosome evolution in spinach. Our findings provide novel insights about the domestication and improvement of spinach.
Journal Article
Identification of structural variation and polymorphisms of a sex co-segregating scaffold in spinach
2022
Spinach is a common vegetable, and dioecy is maintained by a pair of XY sex chromosomes. Due to limited genomic resources and its highly repetitive genome, limited studies were conducted to investigate the genomic landscape of the region near sex-determining loci. In this study, we screened the structure variations (SVs) between Y-linked contigs and a 1.78-Mb X scaffold (Super_scaffold 66), which enabled the development of 12 sex co-segregating DNA markers. These markers were tested in one F
1
mapping population and 40 spinach accessions, which comprised 692 individual plants with the strong sex linkage pattern. In addition, we found that Super_scaffold 66 was highly repetitive along with the enriched LTR-RTs insertions and decreased microsatellite distribution compared with the rest genome, which matches extremely low gene density featured by only nine annotated genes. Synteny analysis between Y contigs and Superscaffold_66 revealed a 340-Kb accumulative Y contig (non-continuous) and a 500-Kb X counterpart along with SVs and wide-spread tandem duplications. Among the nine genes, one ABC transporter gene revealed noticeable SVs between Y contig and X counterpart, as an approximate 5-Kb recent
Gypsy
LTR-RT insertion in the Y-linked allele, but not the X allele. The gene paucity, SVs, and sex-linked polymorphisms attributed to the recombination suppression. We proposed that Super_scaffold 66 is part of the non-recombining region containing the sex determination genes. The spread of 12 sex co-segregating markers from this 1.78 Mb genomic region indicated the existence and expansion of sex determination region during progression of the Y chromosome.
Journal Article
Auxin regulated metabolic changes underlying sepal retention and development after pollination in spinach
2021
Background
Pollination accelerate sepal development that enhances plant fitness by protecting seeds in female spinach. This response requires pollination signals that result in the remodeling within the sepal cells for retention and development, but the regulatory mechanism for this response is still unclear. To investigate the early pollination-induced metabolic changes in sepal, we utilize the high-throughput RNA-seq approach.
Results
Spinach variety ‘Cornel 9’ was used for differentially expressed gene analysis followed by experiments of auxin analog and auxin inhibitor treatments. We first compared the candidate transcripts expressed differentially at different time points (12H, 48H, and 96H) after pollination and detected significant difference in Trp-dependent auxin biosynthesis and auxin modulation and transduction process. Furthermore, several auxin regulatory pathways i.e. cell division, cell wall expansion, and biogenesis were activated from pollination to early developmental symptoms in sepals following pollination. To further confirm the role auxin genes play in the sepal development, auxin analog (2, 4-D; IAA) and auxin transport inhibitor (NPA) with different concentrations gradient were sprayed to the spinach unpollinated and pollinated flowers, respectively. NPA treatment resulted in auxin transport weakening that led to inhibition of sepal development at concentration 0.1 and 1 mM after pollination. 2, 4-D and IAA treatment to unpollinated flowers resulted in sepal development at lower concentration but wilting at higher concentration.
Conclusion
We hypothesized that sepal retention and development might have associated with auxin homeostasis that regulates the sepal size by modulating associated pathways. These findings advanced the understanding of this unusual phenomenon of sepal growth instead of abscission after pollination in spinach.
Journal Article