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Xiuxin Deng - One of the best experts on this subject based on the ideXlab platform.
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Immunoblotting Quantification Approach for Identifying Potential Hypoallergenic Citrus Cultivars
2018Co-Authors: Wenjun Deng, Dingbo Lin, Xiuxin DengAbstract:The inherent allergens of citrus fruits, such as Cit s 1, Cit s 2, Cit s 3 can cause allergic reactions. A better understanding of the genetic factors (cultivar to cultivar) affecting the allergenic potential of citrus fruits would be beneficial for further identification of hypoallergenic genotypes. In the present study, an immunoblotting quantification approach was adopted to assess the potential allergenicity of 21 citrus cultivars, including nine subgroups (tangerine, satsuma, orange, Pummelo, grapefruit, lemon, kumquat, tangor, and tangelo). To prepare highly sensitive and specific rabbit polyclonal antibodies, antigenicity of purified rCit s 1.01, rCit s 2.01, and rCit s 3.01 peptides were enhanced with high epitope density in a single protein molecule. The data integration of three citrus allergen quantifications demonstrated that the four Pummelo cultivars (Kao Phuang Pummelo, Wanbai Pummelo, Shatian Pummelo, and Guanxi Pummelo) were potential hypoallergenic, compared with other 8 subgroups. Moreover, the immunological analyses with sera of allergic subjects revealed that Shatian Pummelo and Guanxi Pummelo showed the lowest immunoreactivity in 8 representative citrus cultivars. These potential hypoallergenic genotypes are of great significance to not only allergic consumers but also citrus breeders in the genetic improvement of hypoallergenic citrus as breeding resources
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Genetic diversity and population structure of Pummelo (Citrus maxima) germplasm in China
Tree Genetics & Genomes, 2017Co-Authors: Xiaoming Yang, Fei Guo, Xiaolin Jiang, Xiuxin DengAbstract:Pummelo (Citrus maxima) is one of the basic species of Citrus. It has been cultivated for about 4000 years in China, and therefore, there are abundant germplasm during the long time of culture. However, there is still a lack of a detailed study of the genetic characteristics of Pummelo population. In this study, genetic diversity and population structure among 274 Pummelo accessions collected in China were analyzed using 31 nuclear simple sequence repeat (nSSR) markers. The observed heterozygosity was calculated as 0.325 and genetic differentiation Fst as 0.077. Genetic structure analysis divided the whole germplasm into three subpopulations, Pop-a, Pop-b, and Pop-c. Pop-a was composed of accessions mostly from Southeast China, Pop-b was composed of accessions from the central region of South China, and Pop-c was composed of accessions from Southwest China. Meanwhile, the analysis of principal coordinate analysis and neighbor-join tree supported the viewpoint of three subpopulations, and then the possible dispersal routes of Pummelos in China were proposed. This study provides an insight into the genetic diversity, facilitates future genome-wide association studies, and promotes the breeding program of Pummelo as well.
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RESEARCH ARTICLE De Novo Transcriptome Assembly of Pummelo and Molecular Marker Development
2016Co-Authors: Mei Liang, Lijun Chai, Xiaoming Yang, Xiuxin DengAbstract:Pummelo (Citrus grandis) is an important fruit crop worldwide because of its nutritional value. To accelerate the Pummelo breeding program, it is essential to obtain extensive ge-netic information and develop relative molecular markers. Here, we obtained a 12-Gb tran-scriptome dataset of Pummelo through a mixture of RNA from seven tissues using Illumina pair-end sequencing, assembled into 57,212 unigenes with an average length of 1010 bp. The annotation and classification results showed that a total of 39,584 unigenes had similar hits to the known proteins of four public databases, and 31,501 were classified into 55 Gene Ontology (GO) functional sub-categories. The search for putative molecular markers among 57,212 unigenes identified 10,276 simple sequence repeats (SSRs) and 64,720 sin-gle nucleotide polymorphisms (SNPs). High-quality primers of 1174 SSR loci were de-signed, of which 88.16 % were localized to nine chromosomes of sweet orange. Of 100 SSR primers that were randomly selected for testing, 87 successfully amplified clear banding pat-terns. Of these primers, 29 with a mean PIC (polymorphic information content) value of 0.52 were effectively applied for phylogenetic analysis. Of the 20 SNP primers, 14 primers, in-cluding 54 potential SNPs, yielded target amplifications, and 46 loci were verified via Sanger sequencing. This new dataset will be a valuable resource for molecular biology studies of Pummelo and provides reliable information regarding SNP and SSRmarker de-velopment, thus expediting the breeding program of Pummelo
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De novo transcriptome assembly of Pummelo and molecular marker development.
PloS one, 2015Co-Authors: Mei Liang, Lijun Chai, Xiaoming Yang, Xiuxin DengAbstract:Pummelo (Citrus grandis) is an important fruit crop worldwide because of its nutritional value. To accelerate the Pummelo breeding program, it is essential to obtain extensive genetic information and develop relative molecular markers. Here, we obtained a 12-Gb transcriptome dataset of Pummelo through a mixture of RNA from seven tissues using Illumina pair-end sequencing, assembled into 57,212 unigenes with an average length of 1010 bp. The annotation and classification results showed that a total of 39,584 unigenes had similar hits to the known proteins of four public databases, and 31,501 were classified into 55 Gene Ontology (GO) functional sub-categories. The search for putative molecular markers among 57,212 unigenes identified 10,276 simple sequence repeats (SSRs) and 64,720 single nucleotide polymorphisms (SNPs). High-quality primers of 1174 SSR loci were designed, of which 88.16% were localized to nine chromosomes of sweet orange. Of 100 SSR primers that were randomly selected for testing, 87 successfully amplified clear banding patterns. Of these primers, 29 with a mean PIC (polymorphic information content) value of 0.52 were effectively applied for phylogenetic analysis. Of the 20 SNP primers, 14 primers, including 54 potential SNPs, yielded target amplifications, and 46 loci were verified via Sanger sequencing. This new dataset will be a valuable resource for molecular biology studies of Pummelo and provides reliable information regarding SNP and SSR marker development, thus expediting the breeding program of Pummelo.
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Construction of a SNP-based high-density genetic map for Pummelo using RAD sequencing.
Tree Genetics & Genomes, 2015Co-Authors: Fei Guo, Xiaolin Jiang, Zheng Tang, Lun Wang, Xia Wang, Xiuxin DengAbstract:Pummelo (Citrus grandis) is one of the most important gene pools for citrus breeding programmes. A high-density linkage map is a valuable tool for functional genomics and genetic breeding studies. A newly developed genome sequence-based marker technology, restriction site-associated DNA (RAD) sequencing, has proven to be powerful for the rapid discovery and genotyping of genome-wide SNP markers and for the high-density genetic map construction. We present the construction of a high-density genetic map of Pummelo using RAD sequencing. An F1 population of 124 individuals and its parents (‘Pingshan’ Pummelo and ‘Guanxi’ Pummelo) were applied to the map construction. One thousand five hundred forty three high-quality single nucleotide polymorphism (SNP) markers were developed and mapped to nine linkage groups. In addition, 20 simple sequence repeat (SSR) markers were included and showed general consistency with the SNP markers. These 1563 markers constituted a total genetic length of 976.58 cM and an average of 0.62 cM between adjacent loci. The number of markers within each linkage group (LG) ranged from 81 (for LG4) to 285 (for LG2). A comparison of the genetic maps to the published sweet orange (Citrus sinensis) genome revealed both conservation and variations. The alignment of the LGs from this map was also shown in comparison with a previously genetic linkage map from Pummelo. This study showed that the RAD sequencing allowed the rapid discovery of a large number of SNPs in the Pummelo. The SNP-based high-density genetic map for Pummelo was successfully generated by using these designed SNP markers. The completed genetic map is a valuable resource for further Pummelo genetic studies and provides useful information for gene positional cloning, MAS breeding and C. grandis genome assembly.
Lijun Chai - One of the best experts on this subject based on the ideXlab platform.
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RESEARCH ARTICLE De Novo Transcriptome Assembly of Pummelo and Molecular Marker Development
2016Co-Authors: Mei Liang, Lijun Chai, Xiaoming Yang, Xiuxin DengAbstract:Pummelo (Citrus grandis) is an important fruit crop worldwide because of its nutritional value. To accelerate the Pummelo breeding program, it is essential to obtain extensive ge-netic information and develop relative molecular markers. Here, we obtained a 12-Gb tran-scriptome dataset of Pummelo through a mixture of RNA from seven tissues using Illumina pair-end sequencing, assembled into 57,212 unigenes with an average length of 1010 bp. The annotation and classification results showed that a total of 39,584 unigenes had similar hits to the known proteins of four public databases, and 31,501 were classified into 55 Gene Ontology (GO) functional sub-categories. The search for putative molecular markers among 57,212 unigenes identified 10,276 simple sequence repeats (SSRs) and 64,720 sin-gle nucleotide polymorphisms (SNPs). High-quality primers of 1174 SSR loci were de-signed, of which 88.16 % were localized to nine chromosomes of sweet orange. Of 100 SSR primers that were randomly selected for testing, 87 successfully amplified clear banding pat-terns. Of these primers, 29 with a mean PIC (polymorphic information content) value of 0.52 were effectively applied for phylogenetic analysis. Of the 20 SNP primers, 14 primers, in-cluding 54 potential SNPs, yielded target amplifications, and 46 loci were verified via Sanger sequencing. This new dataset will be a valuable resource for molecular biology studies of Pummelo and provides reliable information regarding SNP and SSRmarker de-velopment, thus expediting the breeding program of Pummelo
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De novo transcriptome assembly of Pummelo and molecular marker development.
PloS one, 2015Co-Authors: Mei Liang, Lijun Chai, Xiaoming Yang, Xiuxin DengAbstract:Pummelo (Citrus grandis) is an important fruit crop worldwide because of its nutritional value. To accelerate the Pummelo breeding program, it is essential to obtain extensive genetic information and develop relative molecular markers. Here, we obtained a 12-Gb transcriptome dataset of Pummelo through a mixture of RNA from seven tissues using Illumina pair-end sequencing, assembled into 57,212 unigenes with an average length of 1010 bp. The annotation and classification results showed that a total of 39,584 unigenes had similar hits to the known proteins of four public databases, and 31,501 were classified into 55 Gene Ontology (GO) functional sub-categories. The search for putative molecular markers among 57,212 unigenes identified 10,276 simple sequence repeats (SSRs) and 64,720 single nucleotide polymorphisms (SNPs). High-quality primers of 1174 SSR loci were designed, of which 88.16% were localized to nine chromosomes of sweet orange. Of 100 SSR primers that were randomly selected for testing, 87 successfully amplified clear banding patterns. Of these primers, 29 with a mean PIC (polymorphic information content) value of 0.52 were effectively applied for phylogenetic analysis. Of the 20 SNP primers, 14 primers, including 54 potential SNPs, yielded target amplifications, and 46 loci were verified via Sanger sequencing. This new dataset will be a valuable resource for molecular biology studies of Pummelo and provides reliable information regarding SNP and SSR marker development, thus expediting the breeding program of Pummelo.
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Self-sterility in the mutant ‘Zigui shatian’ Pummelo ( Citrus grandis Osbeck) is due to abnormal post-zygotic embryo development and not self-incompatibility
Plant Cell Tissue and Organ Culture (PCTOC), 2010Co-Authors: Lijun Chai, Manosh Kumar Biswas, Xiuxin DengAbstract:‘Shatian’ Pummelo (Citrus grandis Osbeck), one of the main citrus cultivars in China, is self-incompatible, and its pollen tubes are believed to be arrested in style after self-pollination.We have characterized one ‘Shatian’ Pummelo mutant, named ‘Zigui shatian’ Pummelo. The mutant Pummelo had identical DNA ploidy level, morphology (leaf shape, stoma size and density, pollen shape and size) and developmental progress of pistil and male organs to that of the common ‘Shatian’ Pummelo. However, unlike the common ‘Shatian’ Pummelo, ‘Zigui shatian’ is self-compatible since its pollen tubes can self-pollinate allowing for successful fertilization. Histological analyses of ‘Shatian’ Pummelo further verified abnormal post-zygotic development which led to seed abortion. Simple sequence repeats (SSR) analysis revealed polymorphism in 1 of the 120 primers screened showing that ‘Zigui shatian’ and ‘Shatian’ Pummelo are different at the DNA level. Taken together, these data suggested mutant ‘Zigui shatian’ Pummelo might be derived from ‘Shatian’ Pummelo with self-sterility by self-incongruity after self-fertilization.
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Isolation, Characterization, and Expression Analysis of an SKP1-like Gene from ‘Shatian’ Pummelo (Citrus grandis Osbeck)
Plant Molecular Biology Reporter, 2010Co-Authors: Lijun Chai, Manosh Kumar Biswas, Xiuxin DengAbstract:Plant s-phase kinase-associated protein 1 (SKP1) genes have diverse functions in plant developmental and physiological activities. Herein, we described a novel SKP1 gene, designated as CgSKP1, from ‘Shatian’ Pummelo (Citrus grandis Osbeck). The cDNA sequence of CgSKP1 was 603 bp and contained an open reading frame of 477 bp. Genomic sequence of the CgSKP1 gene contained two exons and one intron. The predicted amino acid sequence of this gene is consisted of 158 amino acids with theoretical proteins size of 17.9 kDa. CgSKP1 had high identity with SKP1 genes from other plant species within two conserved region. Full-length cDNAs were also amplified and cloned from six citrus varieties, with 95% nucleotide identity and about 98% amino acid similarity among them. Gel blot analysis suggested that CgSKP1 existed as a single locus in the ‘Shatian’ Pummelo genome. The expression of CgSKP1 was gradually increased during flower developmental stages in ‘Shatian’ Pummelo. Moreover, expression analysis by RT-PCR, qRT-PCR and in situ hybridization of CgSKP1 showed that it was highly expressed in the leaf, petal, anther and ovary, but lowly in the style. These findings indicated that CgSKP1 was closely related to ‘Shatian’ Pummelo flower development.
Xiaoming Yang - One of the best experts on this subject based on the ideXlab platform.
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Genetic diversity and population structure of Pummelo (Citrus maxima) germplasm in China
Tree Genetics & Genomes, 2017Co-Authors: Xiaoming Yang, Fei Guo, Xiaolin Jiang, Xiuxin DengAbstract:Pummelo (Citrus maxima) is one of the basic species of Citrus. It has been cultivated for about 4000 years in China, and therefore, there are abundant germplasm during the long time of culture. However, there is still a lack of a detailed study of the genetic characteristics of Pummelo population. In this study, genetic diversity and population structure among 274 Pummelo accessions collected in China were analyzed using 31 nuclear simple sequence repeat (nSSR) markers. The observed heterozygosity was calculated as 0.325 and genetic differentiation Fst as 0.077. Genetic structure analysis divided the whole germplasm into three subpopulations, Pop-a, Pop-b, and Pop-c. Pop-a was composed of accessions mostly from Southeast China, Pop-b was composed of accessions from the central region of South China, and Pop-c was composed of accessions from Southwest China. Meanwhile, the analysis of principal coordinate analysis and neighbor-join tree supported the viewpoint of three subpopulations, and then the possible dispersal routes of Pummelos in China were proposed. This study provides an insight into the genetic diversity, facilitates future genome-wide association studies, and promotes the breeding program of Pummelo as well.
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RESEARCH ARTICLE De Novo Transcriptome Assembly of Pummelo and Molecular Marker Development
2016Co-Authors: Mei Liang, Lijun Chai, Xiaoming Yang, Xiuxin DengAbstract:Pummelo (Citrus grandis) is an important fruit crop worldwide because of its nutritional value. To accelerate the Pummelo breeding program, it is essential to obtain extensive ge-netic information and develop relative molecular markers. Here, we obtained a 12-Gb tran-scriptome dataset of Pummelo through a mixture of RNA from seven tissues using Illumina pair-end sequencing, assembled into 57,212 unigenes with an average length of 1010 bp. The annotation and classification results showed that a total of 39,584 unigenes had similar hits to the known proteins of four public databases, and 31,501 were classified into 55 Gene Ontology (GO) functional sub-categories. The search for putative molecular markers among 57,212 unigenes identified 10,276 simple sequence repeats (SSRs) and 64,720 sin-gle nucleotide polymorphisms (SNPs). High-quality primers of 1174 SSR loci were de-signed, of which 88.16 % were localized to nine chromosomes of sweet orange. Of 100 SSR primers that were randomly selected for testing, 87 successfully amplified clear banding pat-terns. Of these primers, 29 with a mean PIC (polymorphic information content) value of 0.52 were effectively applied for phylogenetic analysis. Of the 20 SNP primers, 14 primers, in-cluding 54 potential SNPs, yielded target amplifications, and 46 loci were verified via Sanger sequencing. This new dataset will be a valuable resource for molecular biology studies of Pummelo and provides reliable information regarding SNP and SSRmarker de-velopment, thus expediting the breeding program of Pummelo
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De novo transcriptome assembly of Pummelo and molecular marker development.
PloS one, 2015Co-Authors: Mei Liang, Lijun Chai, Xiaoming Yang, Xiuxin DengAbstract:Pummelo (Citrus grandis) is an important fruit crop worldwide because of its nutritional value. To accelerate the Pummelo breeding program, it is essential to obtain extensive genetic information and develop relative molecular markers. Here, we obtained a 12-Gb transcriptome dataset of Pummelo through a mixture of RNA from seven tissues using Illumina pair-end sequencing, assembled into 57,212 unigenes with an average length of 1010 bp. The annotation and classification results showed that a total of 39,584 unigenes had similar hits to the known proteins of four public databases, and 31,501 were classified into 55 Gene Ontology (GO) functional sub-categories. The search for putative molecular markers among 57,212 unigenes identified 10,276 simple sequence repeats (SSRs) and 64,720 single nucleotide polymorphisms (SNPs). High-quality primers of 1174 SSR loci were designed, of which 88.16% were localized to nine chromosomes of sweet orange. Of 100 SSR primers that were randomly selected for testing, 87 successfully amplified clear banding patterns. Of these primers, 29 with a mean PIC (polymorphic information content) value of 0.52 were effectively applied for phylogenetic analysis. Of the 20 SNP primers, 14 primers, including 54 potential SNPs, yielded target amplifications, and 46 loci were verified via Sanger sequencing. This new dataset will be a valuable resource for molecular biology studies of Pummelo and provides reliable information regarding SNP and SSR marker development, thus expediting the breeding program of Pummelo.
Wen-wu Guo - One of the best experts on this subject based on the ideXlab platform.
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induction of parthenogenetic haploid plants using gamma irradiated pollens in hirado buntan Pummelo citrus grandis l osbeck
Scientia Horticulturae, 2016Co-Authors: Shuming Wang, Hong Lan, Huihui Jia, Kaidong Xie, Chunli Chen, Wen-wu GuoAbstract:Abstract Homozygous genotypes have great potential in breeding and genomic researches in higher plants. Induction of parthenogenesis via pollination with gamma-irradiated pollens is an efficient method to obtain haploid plants that can overcome the biological limitations of fruit trees. In this study, we investigated the induction of haploid plants in ‘Hirado Buntan’ pummlo (Citrus grandis) through in-situ gynogenesis by pollination with irradiated pollens of trifoliate orange (255, 325 and 500 Gy) and ‘Tongshui 72-1 Jincheng’ sweet orange (255, 395 and 500 Gy). The pollen stainability, pollen tube behavior after pollination were evaluated. The seeds extracted from the fruits were rescued by in vitro embryo culture, and the ploidy level of the obtained plantlets was determined by flow cytometry. It showed that two haploid plants and one triploid plant, were obtained from the cross-pollination of ‘Hirado Buntan’ Pummelo with irradiated pollens of trifoliate orange; two haploid plants were obtained from the cross-pollination of ‘Hirado Buntan’ pummlo with irradiated pollens of ‘Tongshui 72-1 Jincheng’ sweet orange. The parthenogenic origin of the haploid plants was further confirmed by chromosomal cytogenetic and SSR analysis. The ‘Hirado Buntan’ haploid plants obtained here hold great potential in citrus genetic and genomic studies in the future.
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comparative transcript profiling of a male sterile cybrid Pummelo and its fertile type revealed altered gene expression related to flower development
PLOS ONE, 2012Co-Authors: Beibei Zheng, Jude W Grosser, Xiuxin Deng, Wen-wu GuoAbstract:Male sterile and seedless characters are highly desired for citrus cultivar improvement. In our breeding program, a male sterile cybrid Pummelo, which could be considered as a variant of male fertile Pummelo, was produced by protoplast fusion. Herein, ecotopic stamen primordia initiation and development were detected in this male sterile cybrid Pummelo. Histological studies revealed that the cybrid showed reduced petal development in size and width, and retarded stamen primordia development. Additionally, disorganized cell proliferation was also detected in stamen-like structures (fused to petals and/or carpel). To gain new insight into the underlying mechanism, we compared, by RNA-Seq analysis, the nuclear gene expression profiles of floral buds of the cybrid with that of fertile Pummelo. Gene expression profiles which identified a large number of differentially expressed genes (DEGs) between the two lines were captured at both petal primordia and stamen primordia distinguishable stages. For example, nuclear genes involved in nucleic acid binding and response to hormone synthesis and metabolism, genes required for floral bud identification and expressed in particular floral whorls. Furthermore, in accordance with flower morphology of the cybrid, expression of PISTILLATA (PI) was reduced in stamen-like structures, even though it was restricted to correct floral whorls. Down-regulated expression of APETALA3 (AP3) coincided with that of PI. These finding indicated that, due to their whorl specific effects in flower development, citrus class-B MADS-box genes likely constituted ‘perfect targets’ for CMS retrograde signaling, and that dysfunctional mitochondria seemed to cause male sterile phenotype in the cybrid Pummelo.
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production and molecular characterization of potential seedless cybrid plants between pollen sterile satsuma mandarin and two seedy citrus cultivars
Plant Cell Tissue and Organ Culture, 2007Co-Authors: Xiaodong Cai, Xiuxin Deng, Wen-wu GuoAbstract:Cytoplasmic male sterility (CMS) is known to be controlled by mitochondrial genome in higher plants including Satsuma mandarin (Citrus unshiu Marc.). Citrus symmetric fusion experiments often produce diploid cybrids possessing nuclear DNA from the mesophyll parent and mitochondrial DNA (mtDNA) from the embryogenic callus parent. Therefore, it is possible to transfer CMS from Satsuma mandarin as callus parent to seedy citrus cultivars as leaf one by somatic cybridization. Herein, symmetric fusion technique was adopted to create cybrids for potential seedlessness by transferring CMS from Citrus unshiu Marc. cv. Guoqing No. 1 (G1) to two traditional Chinese seedy citrus cultivars, ‘Shatian’ Pummelo (C. grandis (L) Osbeck) and ‘Bingtang’ orange (C. sinensis (L) Osbeck). Flow cytometry analysis showed that 19 plants recovered from G1 + ‘Bingtang’ orange and 17 of 35 plants regenerated from G1 + ‘Shatian’ Pummelo were diploid. The remaining plants from G1 + ‘Shatian’ Pummelo were tetraploid. The diploid plants from the two combinations were confirmed as true cybrids by simple sequence repeat (SSR) and cleaved amplified polymorphic sequence (CAPS) analysis, with nuclear DNA from their corresponding leaf parent and mtDNA from their common suspension parent, G1 Satsuma mandarin. The remaining plants from G1 + ‘Shatian’ Pummelo were identified as somatic hybrids with mtDNA from G1. The chloroplast simple sequence repeat (cp-SSR) analysis revealed somatic hybrid/cybrid plants from the two combinations in most cases possessed either of their parental chloroplast type, and two plants from G1 +‘Shatian’ Pummelo and all embryoids analyzed from G1 + ‘Bingtang’ orange possessed chloroplast DNA (cpDNA) from both parents. These results demonstrated that we succeeded in introducing mtDNA from G1 Satsuma mandarin into the two target seedy citrus cultivars for potential seedlessness through symmetric fusion.
Jude W Grosser - One of the best experts on this subject based on the ideXlab platform.
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comparative transcript profiling of a male sterile cybrid Pummelo and its fertile type revealed altered gene expression related to flower development
PLOS ONE, 2012Co-Authors: Beibei Zheng, Jude W Grosser, Xiuxin Deng, Wen-wu GuoAbstract:Male sterile and seedless characters are highly desired for citrus cultivar improvement. In our breeding program, a male sterile cybrid Pummelo, which could be considered as a variant of male fertile Pummelo, was produced by protoplast fusion. Herein, ecotopic stamen primordia initiation and development were detected in this male sterile cybrid Pummelo. Histological studies revealed that the cybrid showed reduced petal development in size and width, and retarded stamen primordia development. Additionally, disorganized cell proliferation was also detected in stamen-like structures (fused to petals and/or carpel). To gain new insight into the underlying mechanism, we compared, by RNA-Seq analysis, the nuclear gene expression profiles of floral buds of the cybrid with that of fertile Pummelo. Gene expression profiles which identified a large number of differentially expressed genes (DEGs) between the two lines were captured at both petal primordia and stamen primordia distinguishable stages. For example, nuclear genes involved in nucleic acid binding and response to hormone synthesis and metabolism, genes required for floral bud identification and expressed in particular floral whorls. Furthermore, in accordance with flower morphology of the cybrid, expression of PISTILLATA (PI) was reduced in stamen-like structures, even though it was restricted to correct floral whorls. Down-regulated expression of APETALA3 (AP3) coincided with that of PI. These finding indicated that, due to their whorl specific effects in flower development, citrus class-B MADS-box genes likely constituted ‘perfect targets’ for CMS retrograde signaling, and that dysfunctional mitochondria seemed to cause male sterile phenotype in the cybrid Pummelo.
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production of mandarin Pummelo somatic hybrid citrus rootstocks with potential for improved tolerance resistance to sting nematode
Scientia Horticulturae, 2007Co-Authors: Jude W Grosser, J.l. Chandler, Larry W. DuncanAbstract:Abstract Sting nematode (Belonolaimus longicaudatus Rau) has become a primary factor limiting citrus production in localized regions of the central Florida sandridge citrus production area, making the development of resistant rootstocks a new breeding objective. In efforts to develop a replacement rootstock for the widely adapted sour orange, our focus has been on somatic hybridization of selected mandarin + Pummelo combinations [Grosser, J.W., Gmitter, Jr., F.G., 1990. Protoplast fusion and citrus improvement. Plant Breed. Rev. 8, 339–374; Ananthakrishnan, G., Calovic, M., Serrano, P., Grosser, J.W., 2006. Production of additional allotetraploid somatic hybrids combining mandarins and sweet oranges with pre-selected Pummelos as potential candidates to replace sour orange rootstock. In Vitro Cell. Dev.: Plant 42, 367–371], since sour orange is probably an introgression hybrid of mandarin and Pummelo as suggested by molecular marker analyses [Nicolosi, E., Deng, Z.N., Gentile, A., La Malfa, S., Tribulato, E., 2000. Citrus phylogeny and genetic origin of important species as investigated by molecular markers. Theor. Appl. Genet. 100, 1155–1166; Gulsen, O., Roose, M.L., 2001. Lemons: diversity and relationships with selected Citrus genotypes as measured with nuclear genome markers. J. Am. Soc. Hort. Sci. 126, 309–317]. Somatic hybrid plants were produced from four new mandarin (C. reticulata Blanco) + Pummelo (C. grandis L. Osbeck) parental combinations by fusing embryogenic suspension culture-derived protoplasts isolated from selected mandarins with leaf protoplasts of Pummelo seedlings previously selected for tolerance/resistance to the sting nematode (B. longicaudatus Rau) as follows: Amblycarpa mandarin + ‘Liang Ping Yau’ (seedling) Pummelo seedling SN7; Amblycarpa mandarin + ‘Hirado Buntan Pink’ (HBP) Pummelo seedling SN3; Murcott tangor + Pummelo seedling SN3; and Shekwasha mandarin + Pummelo seedling SN3. Somatic hybridization was verified by ploidy analysis (via flow cytometry) and RAPD analyses. Mandarin parents were selected for wide soil-adaptation and ability to produce friable embryogenic callus lines. Pummelo seedlings used as leaf parents were identified from a previous screen of large seed populations (200 each) from four Pummelos for resistance to sting nematode as follows: ‘Hirado Buntan Pink‘; ‘Red Shaddock‘; ‘Large Pink Pummelo’ and a seedling Pummelo of ‘Liang Ping Yau‘. Ten resistant/tolerant Pummelo seedlings were selected from the 800 Pummelo seeds planted in the screen for further study. The four new somatic hybrids have been propagated to evaluate their horticultural performance and resistance to the sting nematode. These potential somatic hybrid rootstocks should also have potential to control tree size due to polyploidy.
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Production of mandarin + Pummelo somatic hybrid citrus rootstocks with potential for improved tolerance/resistance to sting nematode
Scientia Horticulturae, 2007Co-Authors: Jude W Grosser, J.l. Chandler, Larry W. DuncanAbstract:Abstract Sting nematode (Belonolaimus longicaudatus Rau) has become a primary factor limiting citrus production in localized regions of the central Florida sandridge citrus production area, making the development of resistant rootstocks a new breeding objective. In efforts to develop a replacement rootstock for the widely adapted sour orange, our focus has been on somatic hybridization of selected mandarin + Pummelo combinations [Grosser, J.W., Gmitter, Jr., F.G., 1990. Protoplast fusion and citrus improvement. Plant Breed. Rev. 8, 339–374; Ananthakrishnan, G., Calovic, M., Serrano, P., Grosser, J.W., 2006. Production of additional allotetraploid somatic hybrids combining mandarins and sweet oranges with pre-selected Pummelos as potential candidates to replace sour orange rootstock. In Vitro Cell. Dev.: Plant 42, 367–371], since sour orange is probably an introgression hybrid of mandarin and Pummelo as suggested by molecular marker analyses [Nicolosi, E., Deng, Z.N., Gentile, A., La Malfa, S., Tribulato, E., 2000. Citrus phylogeny and genetic origin of important species as investigated by molecular markers. Theor. Appl. Genet. 100, 1155–1166; Gulsen, O., Roose, M.L., 2001. Lemons: diversity and relationships with selected Citrus genotypes as measured with nuclear genome markers. J. Am. Soc. Hort. Sci. 126, 309–317]. Somatic hybrid plants were produced from four new mandarin (C. reticulata Blanco) + Pummelo (C. grandis L. Osbeck) parental combinations by fusing embryogenic suspension culture-derived protoplasts isolated from selected mandarins with leaf protoplasts of Pummelo seedlings previously selected for tolerance/resistance to the sting nematode (B. longicaudatus Rau) as follows: Amblycarpa mandarin + ‘Liang Ping Yau’ (seedling) Pummelo seedling SN7; Amblycarpa mandarin + ‘Hirado Buntan Pink’ (HBP) Pummelo seedling SN3; Murcott tangor + Pummelo seedling SN3; and Shekwasha mandarin + Pummelo seedling SN3. Somatic hybridization was verified by ploidy analysis (via flow cytometry) and RAPD analyses. Mandarin parents were selected for wide soil-adaptation and ability to produce friable embryogenic callus lines. Pummelo seedlings used as leaf parents were identified from a previous screen of large seed populations (200 each) from four Pummelos for resistance to sting nematode as follows: ‘Hirado Buntan Pink‘; ‘Red Shaddock‘; ‘Large Pink Pummelo’ and a seedling Pummelo of ‘Liang Ping Yau‘. Ten resistant/tolerant Pummelo seedlings were selected from the 800 Pummelo seeds planted in the screen for further study. The four new somatic hybrids have been propagated to evaluate their horticultural performance and resistance to the sting nematode. These potential somatic hybrid rootstocks should also have potential to control tree size due to polyploidy.
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Building a replacement sour orange rootstock: somatic hybridization of selected mandarin + Pummelo combinations
Journal of the American Society for Horticultural Science, 2004Co-Authors: Jude W Grosser, G Ananthakrishnan, Victor Medina-urrutia, Patricia SerranoAbstract:Sour orange has been a premier citrus rootstock worldwide due to its ability to perform on challenging soils and to produce and hold high-quality fruit. However, increasingly widespread quick-decline isolates of citrus tristeza virus (CTV) have destroyed entire industries on sour orange in some countries, and are in the process of destroying millions of trees on sour orange in Florida. CTV also threatens other citrus locations planted heavy to sour orange, including Texas and Mexico. An acceptable alternative rootstock to replace sour orange is in high demand but has yet to be developed. Molecular analyses have recently determined that sour orange is probably a hybrid of Pummelo and mandarin. We report the production of 12 new mandarin + Pummelo somatic hybrids produced by protoplast fusion from selected superior mandarin and Pummelo parents, in efforts to develop a suitable replacement sour-orange-like rootstock that is resistant to CTV-induced quick decline. Somatic hybrids from all 12 parental combinations were con- fi rmed by a combination of leaf morphology, fl ow cytometry, and RAPD analyses (for nuclear hybridity). These new mandarin + Pummelo somatic hybrids are being propagated by rooted cuttings as necessary to conduct quick-decline resistance assays and to assess horticultural performance in replicated fi eld trials.
