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UNREDUCED MEGAGAMETOPHYTE FORMATION VIA SECOND DIVISION RESTITUTION CONTRIBUTES TO TETRAPLOID PRODUCTIONIN INTERPLOIDY CROSSES WITH ‘ORAH’ MANDARIN (CITRUS RETICULATA)

《农业科学与工程前沿（英文）》 2021年 第8卷 第2期

摘要：

Seedless fruits are desirable in the citrus fresh fruit market. Triploid production via diploid × tetraploid interploidy crosses is thought to be the most efficient and widely-used strategy for the breeding of seedless citrus. Although ‘Orah’ mandarin has desirable organoleptic qualities, seeds in the fruits weaken its market competitiveness. To produce new seedless cultivars that are similar to ‘Orah’ mandarin, we performed three 2x × 4x crosses using ‘Orah’ mandarin as the seed parent to regenerate triploid plantlets. A total of 182 triploid and 36 tetraploid plantlets were obtained. By analyzing their genetic origins using nine novel single nucleotide polymorphism (SNP) markers, all of the triploids and tetraploids derived from these three crosses were proven to be hybrids. Also, we demonstrated that 2n megagametophyte formation in ‘Orah’ mandarin result in tetraploid production in these three interploidy crosses. These tetraploid plantlets were genotyped using eight pericentromeric SNP markers and nine centromere distal SNP markers. Based on the genotypes of the 2n megagametophytes, the parental heterozygosity rates in 16 SNP loci and all 2n megagametophytes were less than 50%, indicating that second division restitution was the mechanism underlying 2n megagametophyte formation at both the population and individual levels. These triploid hybrids enrich the germplasm available for seedless breeding. Moreover, the tetraploid hybrids are valuable as parents for ploidy breeding for the production of seedless citrus fruits.

 

关键词： Citrus / 2n gamete / interploidy hybridization / pericentromeric SNP marker / second division restitution    

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UNREDUCED MEGAGAMETOPHYTE FORMATION VIA SECOND DIVISION RESTITUTION CONTRIBUTES TO TETRAPLOID PRODUCTIONIN INTERPLOIDY CROSSES WITH ‘ORAH’ MANDARIN (

Qiangming XIA, Wei WANG, Kaidong XIE, Xiaomeng WU, Xiuxin DENG, Jude W. GROSSER, Wenwu GUO

《农业科学与工程前沿（英文）》   页码 302-313 doi: 10.15302/J-FASE-2021385

摘要： Seedless fruits are desirable in the citrus fresh fruit market. Triploid production via diploid × tetraploid interploidy crosses is thought to be the most efficient and widely-used strategy for the breeding of seedless citrus. Although ‘Orah’ mandarin has desirable organoleptic qualities, seeds in the fruits weaken its market competitiveness. To produce new seedless cultivars that are similar to ‘Orah’ mandarin, we performed three 2x × 4x crosses using ‘Orah’ mandarin as the seed parent to regenerate triploid plantlets. A total of 182 triploid and 36 tetraploid plantlets were obtained. By analyzing their genetic origins using nine novel single nucleotide polymorphism (SNP) markers, all of the triploids and tetraploids derived from these three crosses were proven to be hybrids. Also, we demonstrated that 2n megagametophyte formation in ‘Orah’ mandarin result in tetraploid production in these three interploidy crosses. These tetraploid plantlets were genotyped using eight pericentromeric SNP markers and nine centromere distal SNP markers. Based on the genotypes of the 2n megagametophytes, the parental heterozygosity rates in 16 SNP loci and all 2n megagametophytes were less than 50%, indicating that second division restitution was the mechanism underlying 2n megagametophyte formation at both the population and individual levels. These triploid hybrids enrich the germplasm available for seedless breeding. Moreover, the tetraploid hybrids are valuable as parents for ploidy breeding for the production of seedless citrus fruits.

关键词： Citrus     2n gamete     interploidy hybridization     pericentromeric SNP marker     second division restitution    

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Detection of Huanglongbing (citrus greening) based on hyperspectral image analysis and PCR

Kejian WANG, Dongmei GUO, Yao ZHANG, Lie DENG, Rangjin XIE, Qiang LV, Shilai YI, Yongqiang ZHENG, Yanyan MA, Shaolan HE

《农业科学与工程前沿（英文）》 2019年 第6卷 第2期   页码 172-180 doi: 10.15302/J-FASE-2019256

摘要：

Huanglongbing (HLB, citrus greening) is one of the most serious quarantine diseases of citrus worldwide. To monitor in real-time, recognize diseased trees, and efficiently prevent and control HLB disease in citrus, it is necessary to develop a rapid diagnostic method to detect HLB infected plants without symptoms. This study used Newhall navel orange plants as the research subject, and collected normal color leaf samples and chlorotic leaf samples from a healthy orchard and an HLB-infected orchard, respectively. First, hyperspectral data of the upper and lower leaf surfaces were obtained, and then the polymerase chain reaction (PCR) was used to detect the HLB bacterium in each leaf. The PCR test results showed that all samples from the healthy orchard were negative, and a portion of the samples from the infected orchard were positive. According to these results, the leaf samples from the orchards were divided into disease-free leaves and HLB-positive leaves, and the least squares support vector machine recognition model was established based on the leaf hyperspectral reflectance. The effect on the model of the spectra obtained from the upper and lower leaf surfaces was investigated and different pretreatment methods were compared and analyzed. It was observed that the HLB recognition rate values of the calibration and validation sets based on upper leaf surface spectra under 9-point smoothing pretreatment were 100% and 92.5%, respectively. The recognition rate values based on lower leaf surface spectra under the second-order derivative pretreatment were also 100% and 92.5%, respectively. Both upper and lower leaf surface spectra were available for recognition of HLB-infected leaves, and the HLB PCR-positive leaves could be distinguished from the healthy by the hyperspectral modeling analysis. The results of this study show that early and nondestructive detection of HLB-infected leaves without symptoms is possible, which provides a basis for the hyperspectral diagnosis of citrus with HLB.

关键词： citrus     HLB     hyperspectral     identification     PCR    

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Endemicity of H9N2 and H5N1 avian influenza viruses in poultry in China poses a serious threat to poultry

Jiao HU,Xiufan LIU

《农业科学与工程前沿（英文）》 2016年 第3卷 第1期   页码 11-24 doi: 10.15302/J-FASE-2016092

摘要： The H9N2 and H5N1 avian influenza viruses (AIVs) have been circulating in poultry in China and become endemic since 1998 and 2004, respectively. Currently, they are prevalent in poultry throughout China. This endemicity makes them actively involved in the emergence of the novel lineages of other subtypes of influenza viruses, such as the well-known viruses of the highly pathogenic avian influenza (HPAI) H5N2 and the 2013 novel H7N7, H7N9 and H10N8 subtypes, thereby threatening both the poultry industry and public health. Here, we will review briefly the prevalence and evolution, pathogenicity, transmission, and disease control of these two subtypes and also discuss the possibility of emergence of potentially virulent and highly transmissible AIVs to humans.

关键词： avian influenza virus     H9N2     H5N1     novel viruses     public health    

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Feature extraction of hyperspectral images for detecting immature green citrus fruit

Yongjun DING, Won Suk LEE, Minzan LI

《农业科学与工程前沿（英文）》 2018年 第5卷 第4期   页码 475-484 doi: 10.15302/J-FASE-2018241

摘要：

At an early immature growth stage of citrus, a hyperspectral camera of 369–1042 nm was employed to acquire 30 hyperspectral images in order to detect immature green fruit within citrus trees under natural illumination conditions. First, successive projections algorithm (SPA) were implemented to select 677, 804, 563, 962, and 405 nm wavebands and to construct multispectral images from the original hyperspectral images for further processing. Then, histogram threshold segmentation using NDVI of 804 and 677 nm was implemented to remove image backgrounds. Three slope parameters, calculated from the pairs 405 and 563 nm, 563 and 677 nm, and 804 and 962 nm were used to construct a classifier to identify the potential citrus fruit. Then, a marker-controlled watershed segmentation based on wavelet transform was applied to obtain potential fruit areas. Finally, a green fruit detection model was constructed according to Grey Level Co-occurrence Matrix (GLCM) texture features of the independent areas. Three supervised classifiers, logistic regression, random forest and support vector machine (SVM) were developed using texture features. The detection accuracies were 79%, 75%, and 86% for the logistic regression, random forest, and SVM models, respectively. The developed algorithm showed a great potential for identifying immature green citrus for an early yield estimation.

关键词： hyperspectral     green citrus     image processing     fruit detection     precision agriculture     yield mapping    

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COMPARISON OF POMELO (CITRUS MAXIMA) GROWN IN CHINA AND THAILAND

《农业科学与工程前沿（英文）》 2021年 第8卷 第2期

摘要：

Pomelo is a member of the genus Citrus that is a key contributor to the breeding of modern citrus cultivars. China is the largest producer of pomelo and one of the top five pomelo exporting countries. Pomelos from Thailand are also well-known for their excellent quality and flavor and are ranked in the top ten export countries. This review introduces pomelo planting locations and conditions in China and Thailand. The characteristics and qualities of some commercial pomelo cultivars in China and Thailand are summarized to introduce them to international consumers and to document their similarities and dissimilarities. Data on bioactive compounds and antioxidant capacity are also included for most Chinese and Thai pomelos to highlight how they differ in this aspect because consumers are increasingly interested in healthier foods. In addition, the sensory perception in terms of aroma, flavor, texture and taste attributes and consumer perspective and preferences are discussed.

 

关键词： climate / commercial cultivars / fruit characteristics / lycopene / naringin / sensory evaluation    

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Transcriptome resources and genome-wide marker development for Japanese larch (

Wanfeng LI,Suying HAN,Liwang QI,Shougong ZHANG

《农业科学与工程前沿（英文）》 2014年 第1卷 第1期   页码 77-84 doi: 10.15302/J-FASE-2014010

摘要： While the differential responses of trees to changes in climatic and environmental conditions have been demonstrated as they age, the underlying mechanisms and age control of tree growth and development are complex and poorly understood particularly at a molecular level. In this paper, we present a transcriptome analysis of , a deciduous conifer that is widely-grown in the northern hemisphere and of significant ecological and economic value. Using high-throughput RNA sequencing, we obtained about 26 million reads from the stems of 1-, 2-, 5-, 10-, 25- and 50-year-old trees. Combining these with the published Roche 454 sequencing reads and the expressed sequence tags (both mainly from embryogenic cell cultures), we assembled 26670549 reads into 146786 transcripts, of which we annotated 79182 to support investigations of the molecular basis of tree aging and adaption, somatic embryogenesis and wood formation. Using these sequences we also identified many single-nucleotide polymorphisms, simple sequence repeats, and insertion and deletion markers to assist breeding and genetic diversity studies of .

关键词： Larix     transcriptome     age     wood formation     somatic embryogenesis     molecular marker    

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Rh2O3/hexagonal CePO4 nanocatalysts for N2O decomposition

Huan Liu, Zhen Ma

《化学科学与工程前沿（英文）》 2017年 第11卷 第4期   页码 586-593 doi: 10.1007/s11705-017-1659-6

摘要： Hexagonal CePO nanorods were prepared by a precipitation method and hexagonal CePO nanowires were prepared by hydrothermal synthesis at 150 °C. Rh(NO ) was then used as a precursor for the impregnation of Rh O onto these CePO materials. The Rh O supported on the CePO nanowires was much more active for the catalytic decomposition of N O than the Rh O supported on CePO nanorods. The stability of both catalysts as a function of time on stream was studied and the influence of the co-feed (CO , O , H O or O /H O) on the N O decomposition was also investigated. The samples were characterized by N adsorption-desorption, inductively coupled plasma optical emission spectroscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron microscopy, hydrogen temperature-programmed reduction, oxygen temperature-programmed desorption, and CO temperature-programmed desorption in order to correlate the physicochemical and catalytic properties.

关键词： Rh2O3     CePO4     N2O decomposition    

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Cu-doped Bi/Bi2WO6 catalysts for efficient N2 fixation by photocatalysis

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1412-1422 doi: 10.1007/s11705-023-2312-1

摘要： In this paper, Cu-doped Bi2WO6 was synthesized via a solvothermal method and applied it in photocatalytic N2 immobilization. Characterization results showed the presence of a small amount of metallic Bi in the photocatalyst, indicating that the synthesized photocatalyst is actually Bi/Cu-Bi2WO6 composite. The doped Cu had a valence state of +2 and most likely substituted the position of Bi3+. The introduced Cu did not affect the metallic Bi content, but mainly influenced the energy band structure of Bi2WO6. The band gap was slightly narrowed, the conduction band was elevated, and the work function was reduced. The reduced work function improved the transfer and separation of charge carriers, which mainly caused the increased photoactivity. The optimized NH3 generation rates of Bi/Cu-Bi2WO6 reached 624 and 243 μmol·L–1·g–1·h–1 under simulated solar and visible light, and these values were approximately 2.8 and 5.9 times higher those of Bi/Bi2WO6, respectively. This research provides a method for improving the photocatalytic N2 fixation and may provide more information on the design and preparation of heteroatom-doped semiconductor photocatalysts for N2-to-NH3 conversion.

关键词： Bi2WO6     Cu doping     work function     photocatalytic N2 fixation     charge separation    

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grown TiN/N-TiO composite for enhanced photocatalytic H evolution activity

《能源前沿（英文）》 2021年 第15卷 第3期   页码 721-731 doi: 10.1007/s11708-021-0766-8

摘要： Titanium nitride (TiN) decorated N-doped titania (N-TiO2) composite (TiN/N-TiO2) is fabricated via an in situ nitridation using a hydrothermally synthesized TiO2 and melamine (MA) as raw materials. After the optimization of the reaction condition, the resultant TiN/N-TiO2 composite delivers a hydrogen evolution activity of up to 703 μmol/h under the full spectrum irradiation of Xe-lamp, which is approximately 2.6 and 32.0 times more than that of TiO2 and TiN alone, respectively. To explore the underlying photocatalytic mechanism, the crystal phase, morphology, light absorption, energy band structure, element composition, and electrochemical behavior of the composite material are characterized and analyzed. The results indicate that the superior activity is mainly caused by the in situ formation of plasmonic TiN and N-TiO2 with intimate interface contact, which not only extends the spectral response range, but also accelerates the transfer and separation of the photoexcited hot charge carrier of TiN. The present study provides a fascinating approach to in situ forming nonmetallic plasmonic material/N-doped TiO2 composite photocatalysts for high-efficiency water splitting.

关键词： photocatalytic H2 evolution     TiN/N-TiO2 composite     plasmonic effect     in-situ nitridation    

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Comments on “Determination of heterozygosity for avirulence/virulence loci through sexual hybridization

Ralf T. Voegele

《农业科学与工程前沿（英文）》 2017年 第4卷 第1期   页码 121-122 doi: 10.15302/J-FASE-2017142

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Determination of heterozygosity for avirulence/virulence loci through sexual hybridization of

Yuan TIAN,Gangming ZHAN,Xia LU,Jie ZHAO,Lili HUANG,Zhensheng KANG

《农业科学与工程前沿（英文）》 2017年 第4卷 第1期   页码 48-58 doi: 10.15302/J-FASE-2016114

摘要： Wheat stripe rust caused by f. sp. is one of the most devastating diseases of wheat worldwide and resistant cultivars are vital for its management. Therefore, investigating the heterozygosity of the pathogen is important because of rapid virulence changes in isolates heterozygous for avirulence/virulence. An isolate of f. sp. was selfed on to determine the heterozygosity for avirulence/virulence loci. One hundred and twenty progeny isolates obtained from this selfing were phenotyped using 25 lines of wheat containing genes and genotyped with 96 simple sequencing repeat markers, with 51 pathotypes and 55 multi-locus genotypes being identified. All of these were avirulent on lines with , , , and and virulent on lines with , and , indicating that the parental isolate was homozygously avirulent or homozygously virulent for these loci. Segregation was found for wheat lines with , , , , , , , , , , , , , , , and . The 17 cultivars to which the was identified as heterozygous with respect to virulence/avirulence should not be given priority in breeding programs to obtain new resistant cultivars.

关键词： Puccinia striiformis f. sp. tritici     selfing     heterozygosity     virulence inheritance    

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Effect of 2,5-dimethylfuran addition on ignition delay times of n-heptane at high temperatures

Zhenhua GAO, Erjiang HU, Zhaohua XU, Geyuan YIN, Zuohua HUANG

《能源前沿（英文）》 2019年 第13卷 第3期   页码 464-473 doi: 10.1007/s11708-019-0609-z

摘要： The shock tube autoignition of 2,5-dimethylfuran (DMF)/n-heptane blends (DMF0-100%, by mole fraction) with equivalence ratios of 0.5, 1.0, and 2.0 over the temperature range of 1200–1800 K and pressures of 2.0 atm and 10.0 atm were investigated. A detailed blend chemical kinetic model resulting from the merging of validated kinetic models for the components of the fuel blends was developed. The experimental observations indicate that the ignition delay times nonlinearly increase with an increase in the DMF addition level. Chemical kinetic analysis including radical pool analysis and flux analysis were conducted to explain the DMF addition effects. The kinetic analysis shows that at lower DMF blending levels, the two fuels have negligible impacts on the consumption pathways of each other. As the DMF addition increases to relatively higher levels, the consumption path of n-heptane is significantly changed due to the competition of small radicals, which primarily leads to the nonlinear increase in the ignition delay times of DMF/n-heptane blends.

关键词： ignition delay time     shock tube     kinetic model     2     5-dimethylfuran (DMF)     n-heptane    

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面向语义通信的模分多址技术 Research Article

张平1,2,3,许晓东1,2,3,董辰1,牛凯1,2,梁灏泰1,梁子键1,秦晓琦1,孙梦颖1,陈昊2,马楠1,2,许文俊1,王光宇1,陶小峰2,4

《信息与电子工程前沿（英文）》 2023年 第24卷 第6期   页码 801-812 doi: 10.1631/FITEE.2300196

摘要： 在多用户系统中，系统资源应分配给不同用户。在传统通信系统中，系统资源通常包括时间、频率、空间和功率，因此广泛使用诸如时分多址（TDMA）、频分多址（FDMA）、空分多址（SDMA）、码分多址（CDMA）、非正交多址（NOMA）之类多址技术。在被认为是下一代通信系统新范式的语义通信中，我们从语义角度，以基于模型的人工智能方法，从信源中提取高维语义域特征，并针对信源和信道特征联合构建模型信息空间。从模型信息空间中挖掘语义信息的共性化和个性化信息，提出一种新的基于语义域资源的多址技术，称为模分多址（MDMA）。从信息论角度，证明模分多址比传统多址技术获得更多性能提升。仿真结果表明，模分多址比传统多址技术节省更多带宽资源，并且在低信噪比条件下，在加性高斯白噪声（AWGN）信道中，相比非正交多址具有至少5 dB的性能优势。

关键词： 模分多址（MDMA）；语义通信；多址技术    

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High-order phase-field model with the local and second-order max-entropy approximants

Fatemeh AMIRI

《结构与土木工程前沿（英文）》 2019年 第13卷 第2期   页码 406-416 doi: 10.1007/s11709-018-0475-5

摘要： We approximate the fracture surface energy functional based on phase-field method with smooth local maximum entropy (LME) and second-order maximum entropy (SME) approximants. The higher-order continuity of the meshfree methods such as LME and SME approximants allows to directly solve the fourth-order phase-field equations without splitting the fourth-order differential equation into two second-order differential equations. We will first show that the crack surface functional can be captured more accurately in the fourth-order model with smooth approximants such as LME, SME and B-spline. Furthermore, smaller length scale parameter is needed for the fourth-order model to approximate the energy functional. We also study SME approximants and drive the formulations. The proposed meshfree fourth-order phase-field formulation show more stable results for SME compared to LME meshfree methods.

关键词： second-order maximum entropy     local maximum entropy     second- and fourth-order phase-field models     B-spline    

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标题 作者 时间 类型 操作

UNREDUCED MEGAGAMETOPHYTE FORMATION VIA SECOND DIVISION RESTITUTION CONTRIBUTES TO TETRAPLOID PRODUCTIONIN INTERPLOIDY CROSSES WITH ‘ORAH’ MANDARIN (CITRUS RETICULATA)

期刊论文

UNREDUCED MEGAGAMETOPHYTE FORMATION VIA SECOND DIVISION RESTITUTION CONTRIBUTES TO TETRAPLOID PRODUCTIONIN INTERPLOIDY CROSSES WITH ‘ORAH’ MANDARIN (

Qiangming XIA, Wei WANG, Kaidong XIE, Xiaomeng WU, Xiuxin DENG, Jude W. GROSSER, Wenwu GUO

期刊论文

Detection of Huanglongbing (citrus greening) based on hyperspectral image analysis and PCR

Kejian WANG, Dongmei GUO, Yao ZHANG, Lie DENG, Rangjin XIE, Qiang LV, Shilai YI, Yongqiang ZHENG, Yanyan MA, Shaolan HE

期刊论文

Endemicity of H9N2 and H5N1 avian influenza viruses in poultry in China poses a serious threat to poultry

Jiao HU,Xiufan LIU

期刊论文

Feature extraction of hyperspectral images for detecting immature green citrus fruit

Yongjun DING, Won Suk LEE, Minzan LI

期刊论文

COMPARISON OF POMELO (CITRUS MAXIMA) GROWN IN CHINA AND THAILAND

期刊论文

Transcriptome resources and genome-wide marker development for Japanese larch (

Wanfeng LI,Suying HAN,Liwang QI,Shougong ZHANG

期刊论文

Rh2O3/hexagonal CePO4 nanocatalysts for N2O decomposition

Huan Liu, Zhen Ma

期刊论文

Cu-doped Bi/Bi2WO6 catalysts for efficient N2 fixation by photocatalysis

期刊论文

grown TiN/N-TiO composite for enhanced photocatalytic H evolution activity

期刊论文

Comments on “Determination of heterozygosity for avirulence/virulence loci through sexual hybridization

Ralf T. Voegele

期刊论文

Determination of heterozygosity for avirulence/virulence loci through sexual hybridization of

Yuan TIAN,Gangming ZHAN,Xia LU,Jie ZHAO,Lili HUANG,Zhensheng KANG

期刊论文

Effect of 2,5-dimethylfuran addition on ignition delay times of n-heptane at high temperatures

Zhenhua GAO, Erjiang HU, Zhaohua XU, Geyuan YIN, Zuohua HUANG

期刊论文

面向语义通信的模分多址技术

张平1,2,3,许晓东1,2,3,董辰1,牛凯1,2,梁灏泰1,梁子键1,秦晓琦1,孙梦颖1,陈昊2,马楠1,2,许文俊1,王光宇1,陶小峰2,4

期刊论文

High-order phase-field model with the local and second-order max-entropy approximants

Fatemeh AMIRI

期刊论文