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Ma X, Chang Y, Chen J, Yu M, Wang B, Ye X, Lin Z. Development of wheat-Dasypyrum villosum T6V#4S·6AL translocation lines with enhanced inheritance for powdery mildew resistance. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2022; 135:2423-2435. [PMID: 35644815 DOI: 10.1007/s00122-022-04124-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Abstract
New translocation lines with T6V#4S·6AL in the Ph1 and ph1b backgrounds were developed with improved inheritance of powdery mildew resistance. The wheat-Dasypyrum villosum T6V#4S·6DL translocation line Pm97033, which exhibits strong powdery mildew (PM) resistance, was developed many years ago, but has limited application in wheat breeding. One of the major reasons for this is that the translocation chromosome has low transmission rate, which makes it difficult to obtain ideal genotype through recombination with other elite agronomic traits in a limited segregating population. Further modifications are thus needed to make better use of this genetic resource. In this study, Pm97033 and the T6V#2S·6AL translocation line NY-W were hybridized with the CS ph1b mutant, and two F1 hybrids were hybridized with each other. Then, plants homozygous for the ph1b deletion carrying the alien chromosome arm(s) 6V#2S and 6V#4S were identified from the segregating populations using molecular markers. New T6V#4S·6AL and T6V#2-6V#4S·6AL translocations were identified by molecular markers and confirmed by genomic in situ hybridization (GISH). Individuals that were heterozygous or homozygous for the translocation chromosome in Ph1 and ph1b backgrounds were obtained. The ratio of PM resistance vs. susceptibility in the self-pollinated heterozygous plants was 3:1, and the phenotype was completely consistent with the KASP genotyping. Thus, the new translocation chromosomes had higher transmission rate than the original T6V#4S·6DL, and so can be effectively applied in breeding programs.
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Affiliation(s)
- Xiaolan Ma
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Yanan Chang
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Jingnan Chen
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Mei Yu
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Baicui Wang
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Xingguo Ye
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
- Key Laboratory of Ministry of Agriculture and Rural Affairs of China for Biology and Genetic Breeding of Triticeae Crops, Beijing, 100081, China.
| | - Zhishan Lin
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
- National Key Facility of Crop Gene Resources and Genetic Improvement, Beijing, 100081, China.
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Morgan C, White MA, Franklin FCH, Zickler D, Kleckner N, Bomblies K. Evolution of crossover interference enables stable autopolyploidy by ensuring pairwise partner connections in Arabidopsis arenosa. Curr Biol 2021; 31:4713-4726.e4. [PMID: 34480856 PMCID: PMC8585506 DOI: 10.1016/j.cub.2021.08.028] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/23/2021] [Accepted: 08/09/2021] [Indexed: 11/25/2022]
Abstract
Polyploidy is a major driver of evolutionary change. Autopolyploids, which arise by within-species whole-genome duplication, carry multiple nearly identical copies of each chromosome. This presents an existential challenge to sexual reproduction. Meiotic chromosome segregation requires formation of DNA crossovers (COs) between two homologous chromosomes. How can this outcome be achieved when more than two essentially equivalent partners are available? We addressed this question by comparing diploid, neo-autotetraploid, and established autotetraploid Arabidopsis arenosa using new approaches for analysis of meiotic CO patterns in polyploids. We discover that crossover interference, the classical process responsible for patterning of COs in diploid meiosis, is defective in the neo-autotetraploid but robust in the established autotetraploid. The presented findings suggest that, initially, diploid-like interference fails to act effectively on multivalent pairing and accompanying pre-CO recombination interactions and that stable autopolyploid meiosis can emerge by evolution of a “supercharged” interference process, which can now act effectively on such configurations. Thus, the basic interference mechanism responsible for simplifying CO patterns along chromosomes in diploid meiosis has evolved the capability to also simplify CO patterns among chromosomes in autopolyploids, thereby promoting bivalent formation. We further show that evolution of stable autotetraploidy preadapts meiosis to higher ploidy, which in turn has interesting mechanistic and evolutionary implications. In a neo-autotetraploid, aberrant crossover interference confers aberrant meiosis In a stable autotetraploid, regular crossover interference confers regular meiosis Crossover and synaptic patterns point to evolution of “supercharged” interference Accordingly, evolution of stable autotetraploidy preadapts to higher ploidies
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Affiliation(s)
- Chris Morgan
- John Innes Centre, Colney Lane, Norwich NR4 7UH, UK
| | - Martin A White
- Department of Molecular and Cellular Biology, Harvard University, 52 Oxford Street, Cambridge, MA 02138, USA
| | | | - Denise Zickler
- University Paris-Saclay, Commissariat à l'Energie Atomique at aux Energies Alternatives (CEA), Centre National de la Recherche Scientifique (CNRS), Institute for Integrative Biology of the Cell (I2BC), 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette, France
| | - Nancy Kleckner
- Department of Molecular and Cellular Biology, Harvard University, 52 Oxford Street, Cambridge, MA 02138, USA.
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Serra H, Svačina R, Baumann U, Whitford R, Sutton T, Bartoš J, Sourdille P. Ph2 encodes the mismatch repair protein MSH7-3D that inhibits wheat homoeologous recombination. Nat Commun 2021; 12:803. [PMID: 33547285 PMCID: PMC7865012 DOI: 10.1038/s41467-021-21127-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 01/13/2021] [Indexed: 02/06/2023] Open
Abstract
Meiotic recombination is a critical process for plant breeding, as it creates novel allele combinations that can be exploited for crop improvement. In wheat, a complex allohexaploid that has a diploid-like behaviour, meiotic recombination between homoeologous or alien chromosomes is suppressed through the action of several loci. Here, we report positional cloning of Pairing homoeologous 2 (Ph2) and functional validation of the wheat DNA mismatch repair protein MSH7-3D as a key inhibitor of homoeologous recombination, thus solving a half-century-old question. Similar to ph2 mutant phenotype, we show that mutating MSH7-3D induces a substantial increase in homoeologous recombination (up to 5.5 fold) in wheat-wild relative hybrids, which is also associated with a reduction in homologous recombination. These data reveal a role for MSH7-3D in meiotic stabilisation of allopolyploidy and provides an opportunity to improve wheat's genetic diversity through alien gene introgression, a major bottleneck facing crop improvement.
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Affiliation(s)
- Heïdi Serra
- Genetics, Diversity and Ecophysiology of Cereals, UMR 1095, INRAE, Université Clermont Auvergne, Clermont-Ferrand, France. .,Genetics, Reproduction and Development, CNRS, Inserm, Université Clermont Auvergne, Clermont-Ferrand, France.
| | - Radim Svačina
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of the Region Hana for Biotechnological and Agricultural Research, Olomouc, Czech Republic
| | - Ute Baumann
- School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, PMB1, Glen Osmond, SA, Australia
| | - Ryan Whitford
- School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, PMB1, Glen Osmond, SA, Australia
| | - Tim Sutton
- School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, PMB1, Glen Osmond, SA, Australia.,South Australian Research and Development Institute, Adelaide, SA, Australia
| | - Jan Bartoš
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of the Region Hana for Biotechnological and Agricultural Research, Olomouc, Czech Republic
| | - Pierre Sourdille
- Genetics, Diversity and Ecophysiology of Cereals, UMR 1095, INRAE, Université Clermont Auvergne, Clermont-Ferrand, France.
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Abstract
Recombination and pairing are prominent features of meiosis where they play an important role in increasing genetic diversity. In most organisms recombination also plays mechanical roles in mediating pairing of homologous chromosomes during prophase and in ensuring regular segregation of homologous pairs at the first meiotic division. The laboratory directed by D. von Wettstein identified six key steps in the meiotic process: (1) Recombination mediated processes occur in physical and functional linkage with the synaptonemal complex (SC), a highly conserved, meiosis-specific structure that links homologous axes along their lengths. (2) The pairing process involves formation and resolution of chromosomal entanglements/interlockings. (3) The SC normally forms specifically between homologous chromosomes, but in unusual situations can form between nonhomologous chromosomes or regions resulting in two-phase SC formation. (4) In hexaploid common wheat, extensive multivalents form with multiple, pairing partner shifts, indicating homology recognition and SC formation among homoeologs as well as homologs. (5) Linkage between recombination and the SC is revealed by crossover-correlated nodules localized in the SC central region. (6) Modified SCs sometimes play a direct role in homolog segregation, providing the required connection between homologs in absence of crossovers/chiasmata.
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Li J, Zhao L, Cheng X, Bai G, Li M, Wu J, Yang Q, Chen X, Yang Z, Zhao J. Molecular cytogenetic characterization of a novel wheat-Psathyrostachys huashanica Keng T3DS-5NsL•5NsS and T5DL-3DS•3DL dual translocation line with powdery mildew resistance. BMC PLANT BIOLOGY 2020; 20:163. [PMID: 32293283 PMCID: PMC7161236 DOI: 10.1186/s12870-020-02366-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Accepted: 03/26/2020] [Indexed: 05/26/2023]
Abstract
BACKGROUND Psathyrostachys huashanica Keng (2n = 2x = 14, NsNs) carries many outstanding agronomic traits, therefore is a valuable resource for wheat genetic improvement. Wheat-P. huashanica translocation lines are important intermediate materials for wheat breeding and studying the functions of alien chromosomes. However, powdery mildew resistance in these translocation lines has not been reported previously. RESULTS This study developed a novel wheat-P. huashanica translocation line TR77 by selecting a F7 progeny from the cross between heptaploid hybrid H8911 (2n = 7x = 49, AABBDDNs) and durum wheat line Trs-372. Chromosome karyotype of 2n = 42 = 21II was observed in both mitotic and meiotic stages of TR77. Genomic in situ hybridization analysis identified two translocated chromosomes that paired normally at meiosis stage in TR77. Molecular marker analysis showed that part of chromosome 5D was replaced by part of alien chromosome fragment 5Ns. It meant replacement made part 5DL and part 5NsL·5NsS existed in wheat background, and then translocation happened between these chromosomes and wheat 3D chromosome. Fluorescence in situ hybridization demonstrated that TR77 carries dual translocations: T3DS-5NsL·5NsS and T5DL-3DS·3DL. Analysis using a 15 K-wheat-SNP chip confirmed that SNP genotypes on the 5D chromosome of TR77 matched well with these of P. huashanica, but poorly with common wheat line 7182. The translocation was physically located between 202.3 and 213.1 Mb in 5D. TR77 showed longer spikes, more kernels per spike, and much better powdery mildew resistance than its wheat parents: common wheat line 7182 and durum wheat line Trs-372. CONCLUSIONS TR77 is a novel stable wheat-P. huashanica T3DS-5NsL·5NsS and T5DL-3DS·3DL dual translocation line and showed significant improved spike traits and resistance to powdery mildew compared to its parents, thus, it can be an useful germplasm for breeding disease resistance and studying the genetic mechanism of dual translocations.
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Affiliation(s)
- Jiachuang Li
- Shaanxi Key Laboratory of Plant Genetic Engineering Breeding, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Li Zhao
- Shaanxi Key Laboratory of Plant Genetic Engineering Breeding, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Xueni Cheng
- College of Life Science, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Guihua Bai
- USDA, Hard Winter Wheat Genetics Research Unit, 4008 Throckmorton Hall, Manhattan, KS, 66506, USA
| | - Mao Li
- Shaanxi Key Laboratory of Plant Genetic Engineering Breeding, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Jun Wu
- Shaanxi Key Laboratory of Plant Genetic Engineering Breeding, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Qunhui Yang
- Shaanxi Key Laboratory of Plant Genetic Engineering Breeding, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Xinhong Chen
- Shaanxi Key Laboratory of Plant Genetic Engineering Breeding, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Zujun Yang
- School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, Sichuan, China
| | - Jixin Zhao
- Shaanxi Key Laboratory of Plant Genetic Engineering Breeding, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China.
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Rawale KS, Khan MA, Gill KS. The novel function of the Ph1 gene to differentiate homologs from homoeologs evolved in Triticum turgidum ssp. dicoccoides via a dramatic meiosis-specific increase in the expression of the 5B copy of the C-Ph1 gene. Chromosoma 2019; 128:561-570. [PMID: 31494715 DOI: 10.1007/s00412-019-00724-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 08/12/2019] [Accepted: 08/14/2019] [Indexed: 11/29/2022]
Abstract
The Ph1 gene is the principal regulator of homoeologous chromosome pairing control (HECP) that ensures the diploid-like meiotic chromosome pairing behavior of polyploid wheat. The HECP control was speculated to have evolved after the first event of polyploidization. With the objective to accurately understand the evolution of the HECP control, wild emmer wheat accessions previously known to differ for HECP control were characterized for the structure and expression of the candidate Ph1 gene, C-Ph1. The C-TdPh1-5A and 5B gene copies of emmer wheat showed 98 and 99% DNA sequence similarity respectively with the corresponding hexaploid wheat copies. Further, the C-TdPh1-5B carried the C-Ph1-5B specific structural changes and transcribed three splice variants as observed in the hexaploid wheat. Further, single nucleotide changes differentiating accessions varying for HECP control were identified. Analyzed by quantitative expression analysis, the wild emmer accessions with HECP control showed ~ 10,000-fold higher transcript abundance of the C-TdPh1-5B copy during prophase-I compared to accessions lacking the control. Differential transcriptional regulation of C-TdPh1-5B splice variants further revealed that C-Ph1-5Balt1 variant is mainly responsible for differential accumulation of C-Ph1-5B copy in accessions with HECP control. Taken together, these results showed that the HECP control evolved via transcriptional regulation of splice variants during meiosis.
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Affiliation(s)
- Kanwardeep S Rawale
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA, USA
| | - Muhammad A Khan
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA, USA
| | - Kulvinder S Gill
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA, USA.
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Gyawali Y, Zhang W, Chao S, Xu S, Cai X. Delimitation of wheat ph1b deletion and development of ph1b-specific DNA markers. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2019; 132:195-204. [PMID: 30343385 DOI: 10.1007/s00122-018-3207-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 10/05/2018] [Indexed: 06/08/2023]
Abstract
We detected the deletion breakpoints of wheat ph1b mutant and the actual size of the deletion. Also, we developed ph1b deletion-specific markers useful for ph1b-mediated gene introgression and genome studies. The Ph1 (pairing homoeologous) locus has been considered a major genetic system for the diploidized meiotic behavior of the allopolyploid genome in wheat. It functions as a defense system against meiotic homoeologous pairing and recombination in polyploid wheat. A large deletion of the genomic region harboring Ph1 on the long arm of chromosome 5B (5BL) led to the ph1b mutant in hexaploid wheat 'Chinese Spring,' which has been widely used to induce meiotic homoeologous recombination for gene introgression from wild grasses into wheat. However, the breakpoints and physical size of the deletion remain undetermined. In the present study, we first anchored the ph1b deletion on 5BL by the high-throughput wheat 90K SNP assay and then delimited the deletion to a genomic region of 60,014,523 bp by chromosome walking. DNA marker and sequence analyses detected the nucleotide positions of the distal and proximal breakpoints (DB and PB) of the ph1b deletion and the deletion junction as well. This will facilitate understanding of the genomic region harboring the Ph1 locus in wheat. In addition, we developed user-friendly DNA markers specific for the ph1b deletion. These new ph1b deletion-specific markers will dramatically improve the efficacy of the ph1b mutant in the meiotic homoeologous recombination-based gene introgression and genome studies in wheat and its relatives.
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Affiliation(s)
- Yadav Gyawali
- Department of Plant Sciences, North Dakota State University, Fargo, ND, 58108, USA
| | - Wei Zhang
- Department of Plant Sciences, North Dakota State University, Fargo, ND, 58108, USA
| | - Shiaoman Chao
- USDA-ARS, Red River Valley Agricultural Research Center, Fargo, ND, 58102, USA
| | - Steven Xu
- USDA-ARS, Red River Valley Agricultural Research Center, Fargo, ND, 58102, USA
| | - Xiwen Cai
- Department of Plant Sciences, North Dakota State University, Fargo, ND, 58108, USA.
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9
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Loginova DB, Silkova OG. The Genome of Bread Wheat Triticum aestivum L.: Unique Structural and Functional Properties. RUSS J GENET+ 2018. [DOI: 10.1134/s1022795418040105] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Ronceret A, Vielle-Calzada JP. Meiosis, unreduced gametes, and parthenogenesis: implications for engineering clonal seed formation in crops. PLANT REPRODUCTION 2015; 28:91-102. [PMID: 25796397 DOI: 10.1007/s00497-015-0262-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 03/09/2015] [Indexed: 05/18/2023]
Abstract
Meiosis and unreduced gametes. Sexual flowering plants produce meiotically derived cells that give rise to the male and female haploid gametophytic phase. In the ovule, usually a single precursor (the megaspore mother cell) undergoes meiosis to form four haploid megaspores; however, numerous mutants result in the formation of unreduced gametes, sometimes showing female specificity, a phenomenon reminiscent of the initiation of gametophytic apomixis. Here, we review the developmental events that occur during female meiosis and megasporogenesis at the light of current possibilities to engineer unreduced gamete formation. We also provide an overview of the current understanding of mechanisms leading to parthenogenesis and discuss some of the conceptual implications for attempting the induction of clonal seed production in cultivated plants.
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Affiliation(s)
- Arnaud Ronceret
- Group of Reproductive Development and Apomixis, UGA Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV Irapuato, Km 9.6 Libramiento Norte Carretera Irapuato-León, CP 36821, Irapuato, Guanajuato, Mexico
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Silencing of a metaphase I-specific gene results in a phenotype similar to that of the Pairing homeologous 1 (Ph1) gene mutations. Proc Natl Acad Sci U S A 2014; 111:14187-92. [PMID: 25232038 DOI: 10.1073/pnas.1416241111] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Although studied extensively since 1958, the molecular mode of action of the Pairing homeologous 1 (Ph1) gene is still unknown. In polyploid wheat, the diploid-like chromosome pairing is principally controlled by the Ph1 gene via preventing homeologous chromosome pairing (HECP). Here, we report a candidate Ph1 gene (C-Ph1) present in the Ph1 locus, transient as well as stable silencing of which resulted in a phenotype characteristic of the Ph1 gene mutants, including HECP, multivalent formation, and disrupted chromosome alignment on the metaphase I (MI) plate. Despite a highly conserved DNA sequence, the C-Ph1 gene homeologues showed a dramatically different structure and expression pattern, with only the 5B copy showing MI-specific expression, further supporting our claim for the Ph1 gene. In agreement with the previous reports about the Ph1 gene, the predicted protein of the 5A copy of the C-Ph1 gene is truncated, and thus perhaps less effective. The 5D copy is expressed around the onset of meiosis; thus, it may function during the earlier stages of chromosome pairing. Along with alternate splicing, the predicted protein of the 5B copy is different from the protein of the other two copies because of an insertion. These structural and expression differences among the homeologues concurred with the previous observations about Ph1 gene function. Stable RNAi silencing of the wheat gene in Arabidopsis showed multivalents and centromere clustering during meiosis I.
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Mainiero S, Pawlowski WP. Meiotic chromosome structure and function in plants. Cytogenet Genome Res 2014; 143:6-17. [PMID: 25096046 DOI: 10.1159/000365260] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
Chromosome structure is important for many meiotic processes. Here, we outline 3 main determinants of chromosome structure and their effects on meiotic processes in plants. Cohesins are necessary to hold sister chromatids together until the first meiotic division, ensuring that homologous chromosomes and not sister chromatids separate during anaphase I. During meiosis in maize, Arabidopsis, and rice, cohesins are needed for establishing early prophase chromosome structure and recombination and for aligning bivalents at the metaphase plate. Condensin complexes play pivotal roles in controlling the packaging of chromatin into chromosomes through chromatin compaction and chromosome individualization. In animals and fungi, these complexes establish a meiotic chromosome structure that allows for proper recombination, pairing, and synapsis of homologous chromosomes. In plants, information on the role of condensins in meiosis is limited, but they are known to be required for successful completion of reproductive development. Therefore, we speculate that they play roles similar to animal and fungal condensins during meiosis. Plants generally have large and complex genomes due to frequent polyploidy events, and likely, condensins and cohesins organize chromosomes in such a way as to ensure genome stability. Hexaploid wheat has evolved a unique mechanism using a Ph1 locus-controlled chromosome organization to ensure proper chromosome pairing in meiosis. Altogether, studies on meiotic chromosome structure indicate that chromosome organization is not only important for chromatin packaging but also fulfills specific functions in facilitating chromosome interactions during meiosis, including pairing and recombination.
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Affiliation(s)
- Samantha Mainiero
- Graduate Field of Plant Biology, Cornell University, Ithaca, N.Y., USA
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13
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Gadaleta A, Giancaspro A, Giove SL, Zacheo S, Incerti O, Simeone R, Colasuonno P, Nigro D, Valè G, Cattivelli L, Stanca M, Blanco A. Development of a deletion and genetic linkage map for the 5A and 5B chromosomes of wheat (Triticum aestivum). Genome 2012; 55:417-27. [PMID: 22624876 DOI: 10.1139/g2012-028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The aims of the present study were to provide deletion maps for wheat ( Triticum aestivum L.) chromosomes 5A and 5B and a detailed genetic map of chromosome 5A enriched with popular microsatellite markers, which could be compared with other existing maps and useful for mapping major genes and quantitative traits loci (QTL). Physical mapping of 165 gSSR and EST-SSR markers was conducted by amplifying each primer pair on Chinese Spring, aneuploid lines, and deletion lines for the homoeologous group 5 chromosomes. A recombinant inbred line (RIL) mapping population that is recombinant for only chromosome 5A was obtained by crossing the wheat cultivar Chinese Spring and the disomic substitution line Chinese Spring-5A dicoccoides and was used to develop a genetic linkage map of chromosome 5A. A total of 67 markers were found polymorphic between the parental lines and were mapped in the RIL population. Sixty-three loci and the Q gene were clustered in three linkage groups ordered at a minimum LOD score of 5, while four loci remained unlinked. The whole genetic 5A chromosome map covered 420.2 cM, distributed among three linkage groups of 189.3, 35.4, and 195.5 cM. The EST sequences located on chromosomes 5A and 5B were used for comparative analysis against Brachypodium distachyon (L.) P. Beauv. and rice ( Oryza sativa L.) genomes to resolve orthologous relationships among the genomes of wheat and the two model species.
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Affiliation(s)
- A Gadaleta
- Department of Agro-Forestry and Environmental Biology and Chemistry, Section of Genetics and Plant Breeding, University of Bari Aldo Moro, Via Amendola 165/A, 70126 - Bari, Italy.
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Xue F, Ji W, Wang C, Zhang H, Yang B. High-density mapping and marker development for the powdery mildew resistance gene PmAS846 derived from wild emmer wheat (Triticum turgidum var. dicoccoides). TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2012; 124:1549-1560. [PMID: 22350087 DOI: 10.1007/s00122-012-1809-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Accepted: 01/28/2012] [Indexed: 05/31/2023]
Abstract
Powdery mildew, caused by Blumeria graminis f. sp. tritici, is an important foliar disease of wheat worldwide. The dominant powdery mildew resistance gene PmAS846 was transferred to the hexaploid wheat lines N9134 and N9738 from wild emmer wheat (Triticum dicoccoides) in 1995, and it is still one of the most effective resistance genes in China. A high resolution genetic map for PmAS846 locus was constructed using two F(2) populations and corresponding F(2:3) families developed from the crosses of N9134/Shaanyou 225 and N9738/Huixianhong. Synteny between wheat and Brachypodium distachyon and rice was used to develop closely linked molecular markers to reduce the genetic interval around PmAS846. Twenty-six expressed sequence tag-derived markers were mapped to the PmAS846 locus. Five markers co-segregated with PmAS846 in the F(2) population of N9134/Shaanyou 225. PmAS846 was physically located to wheat chromosome 5BL bin 0.75-0.76 within a gene-rich region. The markers order is conserved between wheat and Brachypodium distachyon, but rearrangements are present in rice. Two markers, BJ261635 and CJ840011 flanked PmAS846 and narrowed PmAS846 to a region that is collinear with 197 and 112 kb genomic regions on Brachypodium chromosome 4 and rice chromosome 9, respectively. The genes located on the corresponding homologous regions in Brachypodium, rice and barley could be considered for further marker saturation and identification of potential candidate genes for PmAS846. The markers co-segregating with PmAS846 provide a potential target site for positional cloning of PmAS846, and can be used for marker-assisted selection of this gene.
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Affiliation(s)
- Fei Xue
- College of Agronomy, State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China
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Tam SM, Hays JB, Chetelat RT. Effects of suppressing the DNA mismatch repair system on homeologous recombination in tomato. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2011; 123:1445-58. [PMID: 21870137 DOI: 10.1007/s00122-011-1679-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2011] [Accepted: 07/30/2011] [Indexed: 05/12/2023]
Abstract
In plant breeding, the ability to manipulate genetic (meiotic) recombination would be beneficial for facilitating gene transfer from wild relatives of crop plants. The DNA mismatch repair (MMR) system helps maintain genetic integrity by correcting base mismatches that arise via DNA synthesis or damage, and antagonizes recombination between homeologous (divergent) DNA sequences. Previous studies have established that the genomes of cultivated tomato (Solanum lycopersicum) and the wild relative S. lycopersicoides are substantially diverged (homeologous) such that recombination between their chromosomes is strongly reduced. Here, we report the effects on homeologous recombination of suppressing endogenous MMR genes in S. lycopersicum via RNAi-induced silencing of SlMSH2 and SlMSH7 or overexpressing dominant negatives of Arabidopsis MSH2 (AtMSH2-DN) in an alien substitution line (SL-8) of S. lycopersicoides in tomato. We show that certain inhibitions of MMR (RNAi of SlMSH7, AtMSH2-DN) are associated with modest increases in homeologous recombination, ranging from 3.8 to 29.2% (average rate of 17.8%) compared to controls. Unexpectedly, only the AtMSH2-DN proteins but not RNAi-induced silencing of MSH2 was found to increase homeologous recombination. The ratio of single to double crossovers (SCO:DCO ratio) decreased by approximately 50% in progeny of the AtMSH2-DN parents. An increase in the frequency of heterozygous SL-8 plants was also observed in the progeny of the SlMSH7-RNAi parents. Our findings may contribute to acceleration of introgression in cultivated tomato.
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Affiliation(s)
- Sheh May Tam
- Department of Plant Sciences, University of California Davis, One Shields Avenue, Davis, CA 95616, USA
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16
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Jauhar PP, Peterson TS. Synthesis and cytological analyses of hybrids between hexaploid wheat, with and without Ph1, and diploid wheatgrass. THE NUCLEUS 2011. [DOI: 10.1007/s13237-011-0037-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
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17
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Niu Z, Klindworth DL, Friesen TL, Chao S, Jin Y, Cai X, Xu SS. Targeted introgression of a wheat stem rust resistance gene by DNA marker-assisted chromosome engineering. Genetics 2011; 187:1011-21. [PMID: 21242535 PMCID: PMC3070511 DOI: 10.1534/genetics.110.123588] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Accepted: 01/11/2011] [Indexed: 11/18/2022] Open
Abstract
Chromosome engineering is a useful strategy for transfer of alien genes from wild relatives into modern crops. However, this strategy has not been extensively used for alien gene introgression in most crops due to low efficiency of conventional cytogenetic techniques. Here, we report an improved scheme of chromosome engineering for efficient elimination of a large amount of goatgrass (Aegilops speltoides) chromatin surrounding Sr39, a gene that provides resistance to multiple stem rust races, including Ug99 (TTKSK) in wheat. The wheat ph1b mutation, which promotes meiotic pairing between homoeologous chromosomes, was employed to induce recombination between wheat chromosome 2B and goatgrass 2S chromatin using a backcross scheme favorable for inducing and detecting the homoeologous recombinants with small goatgrass chromosome segments. Forty recombinants with Sr39 with reduced surrounding goatgrass chromatin were quickly identified from 1048 backcross progenies through disease screening and molecular marker analysis. Four of the recombinants carrying Sr39 with a minimal amount of goatgrass chromatin (2.87-9.15% of the translocated chromosomes) were verified using genomic in situ hybridization. Approximately 97% of the goatgrass chromatin was eliminated in one of the recombinants, in which a tiny goatgrass chromosome segment containing Sr39 was retained in the wheat genome. Localization of the goatgrass chromatin in the recombinants led to rapid development of three molecular markers tightly linked to Sr39. The new wheat lines and markers provide useful resources for the ongoing global effort to combat Ug99. This study has demonstrated great potential of chromosome engineering in genome manipulation for plant improvement.
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Affiliation(s)
- Zhixia Niu
- Department of Agriculture, Agricultural Research Service, Northern Crop Science Laboratory, Fargo, North Dakota 58102-2765, Department of Agriculture, Agricultural Research Service, Cereal Disease Laboratory, Saint Paul, Minnesota 55108 and Departments of Plant Sciences, North Dakota State University, Fargo, North Dakota 58108-6050
| | - Daryl L. Klindworth
- Department of Agriculture, Agricultural Research Service, Northern Crop Science Laboratory, Fargo, North Dakota 58102-2765, Department of Agriculture, Agricultural Research Service, Cereal Disease Laboratory, Saint Paul, Minnesota 55108 and Departments of Plant Sciences, North Dakota State University, Fargo, North Dakota 58108-6050
| | - Timothy L. Friesen
- Department of Agriculture, Agricultural Research Service, Northern Crop Science Laboratory, Fargo, North Dakota 58102-2765, Department of Agriculture, Agricultural Research Service, Cereal Disease Laboratory, Saint Paul, Minnesota 55108 and Departments of Plant Sciences, North Dakota State University, Fargo, North Dakota 58108-6050
| | - Shiaoman Chao
- Department of Agriculture, Agricultural Research Service, Northern Crop Science Laboratory, Fargo, North Dakota 58102-2765, Department of Agriculture, Agricultural Research Service, Cereal Disease Laboratory, Saint Paul, Minnesota 55108 and Departments of Plant Sciences, North Dakota State University, Fargo, North Dakota 58108-6050
| | - Yue Jin
- Department of Agriculture, Agricultural Research Service, Northern Crop Science Laboratory, Fargo, North Dakota 58102-2765, Department of Agriculture, Agricultural Research Service, Cereal Disease Laboratory, Saint Paul, Minnesota 55108 and Departments of Plant Sciences, North Dakota State University, Fargo, North Dakota 58108-6050
| | - Xiwen Cai
- Department of Agriculture, Agricultural Research Service, Northern Crop Science Laboratory, Fargo, North Dakota 58102-2765, Department of Agriculture, Agricultural Research Service, Cereal Disease Laboratory, Saint Paul, Minnesota 55108 and Departments of Plant Sciences, North Dakota State University, Fargo, North Dakota 58108-6050
| | - Steven S. Xu
- Department of Agriculture, Agricultural Research Service, Northern Crop Science Laboratory, Fargo, North Dakota 58102-2765, Department of Agriculture, Agricultural Research Service, Cereal Disease Laboratory, Saint Paul, Minnesota 55108 and Departments of Plant Sciences, North Dakota State University, Fargo, North Dakota 58108-6050
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18
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Gene conversion in angiosperm genomes with an emphasis on genes duplicated by polyploidization. Genes (Basel) 2011; 2:1-20. [PMID: 24710136 PMCID: PMC3924838 DOI: 10.3390/genes2010001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Revised: 12/06/2010] [Accepted: 01/06/2011] [Indexed: 11/16/2022] Open
Abstract
Angiosperm genomes differ from those of mammals by extensive and recursive polyploidizations. The resulting gene duplication provides opportunities both for genetic innovation, and for concerted evolution. Though most genes may escape conversion by their homologs, concerted evolution of duplicated genes can last for millions of years or longer after their origin. Indeed, paralogous genes on two rice chromosomes duplicated an estimated 60–70 million years ago have experienced gene conversion in the past 400,000 years. Gene conversion preserves similarity of paralogous genes, but appears to accelerate their divergence from orthologous genes in other species. The mutagenic nature of recombination coupled with the buffering effect provided by gene redundancy, may facilitate the evolution of novel alleles that confer functional innovations while insulating biological fitness of affected plants. A mixed evolutionary model, characterized by a primary birth-and-death process and occasional homoeologous recombination and gene conversion, may best explain the evolution of multigene families.
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Yousafzai FK, Al-Kaff N, Moore G. The molecular features of chromosome pairing at meiosis: the polyploid challenge using wheat as a reference. Funct Integr Genomics 2010; 10:147-56. [PMID: 20422242 DOI: 10.1007/s10142-010-0171-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Revised: 03/18/2010] [Accepted: 03/27/2010] [Indexed: 11/29/2022]
Abstract
During meiosis, chromosome numbers are halved, leading to haploid gametes, a process that is crucial for the maintenance of a stable genome through successive generations. The process for the accurate segregation of the homologues starts in pre-meiosis as each homologue is replicated and the respective products are held together as two sister chromatids via specific cohesion proteins. At the start of meiosis, each chromosome must recognise its homologue from amongst all the chromosomes present in the nucleus and then associate or pair with that homologue. This process of homologue recognition in meiosis is more complicated in polyploids because of the greater number of related chromosomes. Despite the presence of these related chromosomes, for polyploids such as wheat to produce viable gametes, they must behave as diploids during meiosis with only true homologues pairing. In this review, the relationship between the Ph1 cyclin-dependent kinase (CDK)-like genes in wheat and the CDK2 genes in mammals and their involvement in controlling this process at meiosis is examined.
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Suzuki G. Recent progress in plant reproduction research: the story of the male gametophyte through to successful fertilization. PLANT & CELL PHYSIOLOGY 2009; 50:1857-64. [PMID: 19825944 DOI: 10.1093/pcp/pcp142] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Sexual reproduction is an important biological event not only for evolution but also for breeding in plants. It is a well known fact that Charles Darwin (1809-1882) was interested in the reproduction system of plants as part of his concept of 'species' and 'evolution.' His keen observation and speculation is timeless even in the current post-genome era. In the Darwin anniversary year of 2009, I have summarized recent molecular genetic studies of plant reproduction, focusing especially on male gametophyte development, pollination and fertilization. We are just beginning to understand the molecular mechanisms of the elaborate reproduction system in flowering plants, which have been a mystery for >100 years.
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Affiliation(s)
- Go Suzuki
- Division of Natural Science, Osaka Kyoiku University, Kashiwara, 582-8582 Japan.
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Cifuentes M, Benavente E. Complete characterization of wheat-alien metaphase I pairing in interspecific hybrids between durum wheat (Triticum turgidum L.) and jointed goatgrass (Aegilops cylindrica Host). TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2009; 118:1609-1616. [PMID: 19319503 DOI: 10.1007/s00122-009-1009-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Accepted: 03/08/2009] [Indexed: 05/27/2023]
Abstract
The pattern of homoeologous metaphase I (MI) pairing has been fully characterized in durum wheat x Aegilops cylindrica hybrids (2n = 4x = 28, ABC(c)D(c)) by an in situ hybridization procedure that has permitted individual discrimination of every wheat and wild constituent genome. One of the three hybrid genotypes examined carried the ph1c mutation. In all cases, MI associations between chromosomes of both species represented around two-third of total. Main results from the analysis are as follows (a) the A genome chromosomes are involved in wheat-wild MI pairing more frequently than the B genome partners, irrespective of the alien genome considered; (b) both durum wheat genomes pair preferentially with the D(c) genome of jointed goatgrass. These findings are discussed in relation to the potential of genetic transference between wheat crops and this weedy relative. It can also be highlighted that inactivation of Ph1 provoked a relatively higher promotion of MI associations involving B genome.
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Affiliation(s)
- Marta Cifuentes
- Departamento de Biotecnología, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
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Abstract
Centromeres are an essential and conserved feature of eukaryotic chromosomes, yet recent research indicates that we are just beginning to understand the numerous roles that centromeres have in chromosome segregation. During meiosis I, in particular, centromeres seem to function in many processes in addition to their canonical role in assembling kinetochores, the sites of microtubule attachment. Here we summarize recent advances that place centromeres at the centre of meiosis I, and discuss how these studies affect a variety of basic research fields and thus hold promise for increasing our understanding of human reproductive defects and disease states.
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Khoo KHP, Jolly HR, Able JA. The RAD51 gene family in bread wheat is highly conserved across eukaryotes, with RAD51A upregulated during early meiosis. FUNCTIONAL PLANT BIOLOGY : FPB 2008; 35:1267-1277. [PMID: 32688873 DOI: 10.1071/fp08203] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2008] [Accepted: 09/25/2008] [Indexed: 06/11/2023]
Abstract
The RADiation sensitive protein 51 (RAD51) recombinase is a eukaryotic homologue of the bacterial Recombinase A (RecA). It is required for homologous recombination of DNA during meiosis where it plays a role in processes such as homology searching and strand invasion. RAD51 is well conserved in eukaryotes with as many as four paralogues identified in vertebrates and some higher plants. Here we report the isolation and preliminary characterisation of four RAD51 gene family members in hexaploid (bread) wheat (Triticum aestivum L.). RAD51A1, RAD51A2 and RAD51D were located on chromosome group 7, and RAD51C was on chromosome group 2. Q-PCR gene expression profiling revealed that RAD51A1 was upregulated during meiosis with lower expression levels seen in mitotic tissue, and bioinformatics analysis demonstrated the evolutionary linkages of this gene family to other eukaryotic RAD51 sequences. Western blot analysis of heterologously expressed RAD51 from bread wheat has shown that it is detectable using anti-human RAD51 antibodies and that molecular modelling of the same protein revealed structural conservation when compared with yeast, human, Arabidopsis and maize RAD51A orthologues. This report has widened the knowledge base of this important protein family in plants, and highlighted the high level of structural conservation among RAD51 proteins from various species.
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Affiliation(s)
- Kelvin H P Khoo
- School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, PMB1, Glen Osmond, SA 5064, Australia
| | - Hayley R Jolly
- School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, PMB1, Glen Osmond, SA 5064, Australia
| | - Jason A Able
- School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, PMB1, Glen Osmond, SA 5064, Australia
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