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Wang C, Shi C, Huang W, Zhang M, He J. The Impact of Aboveground Epichloë Endophytic Fungi on the Rhizosphere Microbial Functions of the Host Melica transsilvanica. Microorganisms 2024; 12:956. [PMID: 38792786 PMCID: PMC11124418 DOI: 10.3390/microorganisms12050956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 05/05/2024] [Accepted: 05/07/2024] [Indexed: 05/26/2024] Open
Abstract
In nature, the symbiotic relationship between plants and microorganisms is crucial for ecosystem balance and plant growth. This study investigates the impact of Epichloë endophytic fungi, which are exclusively present aboveground, on the rhizosphere microbial functions of the host Melica transsilvanica. Using metagenomic methods, we analyzed the differences in microbial functional groups and functional genes in the rhizosphere soil between symbiotic (EI) and non-symbiotic (EF) plants. The results reveal that the presence of Epichloë altered the community structure of carbon and nitrogen cycling-related microbial populations in the host's rhizosphere, significantly increasing the abundance of the genes (porA, porG, IDH1) involved in the rTCA cycle of the carbon fixation pathway, as well as the abundance of nxrAB genes related to nitrification in the nitrogen-cycling pathway. Furthermore, the presence of Epichloë reduces the enrichment of virulence factors in the host rhizosphere microbiome, while significantly increasing the accumulation of resistance genes against heavy metals such as Zn, Sb, and Pb. This study provides new insights into the interactions among endophytic fungi, host plants, and rhizosphere microorganisms, and offers potential applications for utilizing endophytic fungi resources to improve plant growth and soil health.
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Affiliation(s)
| | - Chong Shi
- College of Resources and Environment, Xinjiang Agricultural University, Urumqi 830052, China; (C.W.); (W.H.); (M.Z.); (J.H.)
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Chen Y, Xu C, Ma K, Hou Q, Yu X. Responses of community traits and soil characteristics of Achnatherum inebrians-type degraded grassland to grazing systems in alpine meadows on the Qinghai-Tibet Plateau. FRONTIERS IN PLANT SCIENCE 2023; 14:1270304. [PMID: 37868308 PMCID: PMC10587598 DOI: 10.3389/fpls.2023.1270304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 09/14/2023] [Indexed: 10/24/2023]
Abstract
Introduction Scientific grazing management is of great significance for the ecological health and sustainable use of alpine meadows. Methods To explore appropriate management methods of alpine grasslands of the Qinghai-Tibet Plateau degraded by Achnatherum inebrians (Hance) Keng ex Tzvele presence, we studied the effects of different grazing systems on the A. inebrians population, grassland vegetation community traits, soil characteristics and soil microbial community structure for cold- season grazing plus supplementary feeding pasture (CSF) and four-season open public pasture (FOP) in Tianzhu County, Gansu Province. Results Compared with FOP, the CSF site showed significantly inhibited reproduction of A. inebrians, especially the crown width, seed yield and number of reproductive branches per plant were as high as 50%, significantly increased the aboveground biomass of edible forage and soil water content by 57% and 43-55%, better soil nutrients, and significantly reduced soil bulk density by 10- 29%. Different grazing systems affected the composition and diversity of soil microbial communities, with a greater effect on fungi than on bacterial flora. The most abundant phyla of bacteria and fungi were Proteobacteria and Ascomycota for CSF (by 30-38% and 24-28%) and for FOP (by 67-70% and 68-73%), and the relative abundance and species of bacterial and fungal genera were greater for CSF than FOP. The α-diversity indexes of fungi were improved, and the β-diversity of fungi was significant difference between CSF and FOP. However, the grazing utilization time was prolonged in FOP, which reduced the diversity and abundance of soil bacteria and increased soil spatial heterogeneity. The use of A. inebrians-type degraded grassland in the cold season, and as a winter supplementary feeding and resting ground, could effectively inhibit expansion of A. inebrians, promote edible forage growth, enhance grassland productivity and community stability, and improve soil structure. Discussion The results guide healthy and sustainable utilization of A. inebrians-type degraded grassland in the Qinghai-Tibet Plateau.
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Affiliation(s)
| | | | | | | | - Xiaojun Yu
- Grassland Ecosystem Key Laboratory of Ministry of Education, Sino-U.S. Research Center for Grazing Land Ecosystem Sustainability, Grassland Pratacultural College of Gansu Agricultural University, Lanzhou, Gansu, China
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Identification of Three Epichloë Endophytes from Hordeum bogdanii Wilensky in China. J Fungi (Basel) 2022; 8:jof8090928. [PMID: 36135653 PMCID: PMC9502125 DOI: 10.3390/jof8090928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/19/2022] [Accepted: 08/27/2022] [Indexed: 11/24/2022] Open
Abstract
Cool season grasses often form reciprocal symbiotic relationships with endophytic fungal species in genus Epichloë. In this study, we characterized three fungal endophytes isolated from the grass Hordeum bogdanii native to northwest China. Based on morphological characteristics and phylogenetic analyses of tefA, tubB, and actG sequences, we identified them as Epichloë sp. HboTG-2 (H. bogdanii Taxonomic Group 2: E. bromicola × E. typhina). Alkaloid synthesis related genes analysis showed that Epichloë sp. HboTG-2 may have the ability only to produce peramine which is toxic to insects but not to animals. In the process of this study, we did not observe sexual structures or epiphyllous growth on leaves of infected plants.
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Epichloë scottii sp. nov., a new endophyte isolated from Melica uniflora is the missing ancestor of Epichloë disjuncta. IMA Fungus 2022; 13:2. [PMID: 35109929 PMCID: PMC8812020 DOI: 10.1186/s43008-022-00088-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 01/25/2022] [Indexed: 11/13/2022] Open
Abstract
Here we describe a new, haploid and stroma forming species within the genus Epichloë, as Epichloë scottii sp. nov. The fungus was isolated from Melica uniflora growing in Bad Harzburg, Germany. Phylogenetic reconstruction using a combined dataset of the tubB and tefA genes strongly support that E. scottii is a distinct species and the so far unknown ancestor species of the hybrid E. disjuncta. A distribution analysis showed a high infection rate in close vicinity of the initial sampling site and only two more spots with low infection rates. Genetic variations in key genes required for alkaloid production suggested that E. scottii sp. nov. might not be capable of producing any of the major alkaloids including ergot alkaloid, loline, indole-diterpene and peramine. All isolates and individuals found in the distribution analysis were identified as mating-type B explaining the lack of mature stromata during this study. We further release a telomere-to-telomere de novo assembly of all seven chromosomes and the mitogenome of E. scottii sp. nov.
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Tian P, Xu W, Li C, Song H, Wang M, Schardl CL, Nan Z. Phylogenetic relationship and taxonomy of a hybrid Epichloë species symbiotic with Festuca sinensis. Mycol Prog 2020. [DOI: 10.1007/s11557-020-01618-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Shi X, Qin T, Liu H, Wu M, Li J, Shi Y, Gao Y, Ren A. Endophytic Fungi Activated Similar Defense Strategies of Achnatherum sibiricum Host to Different Trophic Types of Pathogens. Front Microbiol 2020; 11:1607. [PMID: 32793143 PMCID: PMC7393327 DOI: 10.3389/fmicb.2020.01607] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 06/19/2020] [Indexed: 12/17/2022] Open
Abstract
It is well documented that Epichloë endophytes can enhance the resistance of grasses to herbivory. However, reports on resistance to pathogenic fungi are limited, and their conclusions are variable. In this study, we chose pathogenic fungi with different trophic types, namely, the biotrophic pathogen Erysiphales species and the necrotrophic pathogen Curvularia lunata, to test the effects of Epichloë on the pathogen resistance of Achnatherum sibiricum. The results showed that, compared to Erysiphales species, C. lunata caused a higher degree of damage and lower photochemical efficiency (Fv/Fm) in endophyte−free (E−) leaves. Endophytes significantly alleviated the damage caused by these two pathogens. The leaf damaged area and Fv/Fm of endophyte−infected (E+) leaves were similar between the two pathogen treatments, indicating that the beneficial effects of endophytes were more significant when hosts were exposed to C. lunata than when they were exposed to Erysiphales species. We found that A. sibiricum initiated jasmonic acid (JA)−related pathways to resist C. lunata but salicylic acid (SA)–related pathways to resist Erysiphales species. Endophytic fungi had no effect on the content of SA but increased the content of JA and total phenolic compounds, which suggest that endophyte infection might enhance the resistance of A. sibiricum to these two different trophic types of pathogens through similar pathways.
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Cagnano G, Lenk I, Roulund N, Jensen CS, Cox MP, Asp T. Mycelial biomass and concentration of loline alkaloids driven by complex population structure in Epichloë uncinata and meadow fescue ( Schedonorus pratensis). Mycologia 2020; 112:474-490. [PMID: 32412888 DOI: 10.1080/00275514.2020.1746607] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Many efforts have been made to select and isolate naturally occurring animal-friendly Epichloë strains for later reinfection into elite cultivars. Often this process involves large-scale screening of Epichloë-infected wild grass populations where strains are characterized and alkaloids measured. Here, we describe for the first time the use of genotyping-by-sequencing (GBS) on a collection of 217 Epichloë-infected grasses (7 S. arundinaceum, 4 L. perenne, and 206 S. pratensis). This genotyping strategy is cheaper than complete genome sequencing, is suitable for a large number of individuals, and, when applied to endophyte-infected grasses, conveniently genotypes both organisms. In total, 6273 single nucleotide polymorphisms (SNPs) in the endophyte data set and 38 323 SNPs in the host data set were obtained. Our findings reveal a composite structure with three distinct endophyte clusters unrelated to the three main S. pratensis gene pools that have most likely spread from different glacial refugia in Eurasia. All three gene pools can establish symbiosis with E. uncinata. A comparison of the endophyte clusters with microsatellite-based fingerprinting of the same samples allows a quick test to discriminate between these clusters using two simple sequence repeats (SSRs). Concentrations of loline alkaloids and mycelial biomass are correlated and differ significantly among the plant and endophyte subpopulations; one endophyte strain has higher levels of lolines than others, and one specific host genotype is particularly suitable to host E. uncinata. These findings pave the way for targeted artificial inoculations of specific host-endophyte combinations to boost loline production in the symbiota and for genome association studies with the aim of isolating genes involved in the compatibility between meadow fescue and E. uncinata.
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Affiliation(s)
- G Cagnano
- DLF Seeds A/S, Højerupvej 31, 4660 Store Heddinge , Denmark
| | - I Lenk
- DLF Seeds A/S, Højerupvej 31, 4660 Store Heddinge , Denmark
| | - N Roulund
- DLF Seeds A/S, Højerupvej 31, 4660 Store Heddinge , Denmark
| | - C S Jensen
- DLF Seeds A/S, Højerupvej 31, 4660 Store Heddinge , Denmark
| | - M P Cox
- Statistics and Bioinformatics Group, School of Fundamental Sciences, Massey University , Palmerston North 4442, New Zealand
| | - T Asp
- Department of Molecular Biology and Genetics, Faculty of Science and Technology, Aarhus University , Aarhus, Denmark
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Effects of Epichloë gansuensis on root-associated fungal communities of Achnatherum inebrians under different growth conditions. FUNGAL ECOL 2018. [DOI: 10.1016/j.funeco.2017.10.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Campbell MA, Tapper BA, Simpson WR, Johnson RD, Mace W, Ram A, Lukito Y, Dupont PY, Johnson LJ, Scott DB, Ganley ARD, Cox MP. Epichloë hybrida, sp. nov., an emerging model system for investigating fungal allopolyploidy. Mycologia 2018; 109:715-729. [PMID: 29370579 DOI: 10.1080/00275514.2017.1406174] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Endophytes of the genus Epichloë (Clavicipitaceae, Ascomycota) frequently occur within cool-season grasses and form interactions with their hosts that range from mutualistic to antagonistic. Many Epichloë species have arisen via interspecific hybridization, resulting in species with two or three subgenomes that retain all or nearly all of their original parental genomes, a process termed allopolyploidization. Here, we characterize Epichloë hybrida, sp. nov., a mutualistic species that has increasingly become a model system for investigating allopolyploidy in fungi. The Epichloë species so far identified as the closest known relatives of the two progenitors of E. hybrida are E. festucae var. lolii and E. typhina. We confirm that the nuclear genome of E. hybrida contains two homeologs of most protein-coding genes from E. festucae and E. typhina, with genome-wide gene expression analysis indicating a slight bias in overall gene expression from the E. typhina subgenome. Mitochondrial DNA is detectable only from E. festucae, whereas ribosomal DNA is detectable only from E. typhina. Inheriting ribosomal DNA from just one parent might be expected to preferentially favor interactions with ribosomal proteins from the same parent, but we find that ribosomal protein genes from both parental subgenomes are nearly all expressed equally in E. hybrida. Finally, we provide a comprehensive set of resources for this model system that are intended to facilitate further study of fungal hybridization by other researchers.
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Affiliation(s)
- Matthew A Campbell
- a Institute of Fundamental Sciences, Massey University , Private Bag 11 222, Palmerston North 4410 , New Zealand
| | - Brian A Tapper
- b AgResearch Ltd., Grasslands Research Centre , Tennent Drive, Palmerston North 4442 , New Zealand
| | - Wayne R Simpson
- b AgResearch Ltd., Grasslands Research Centre , Tennent Drive, Palmerston North 4442 , New Zealand
| | - Richard D Johnson
- b AgResearch Ltd., Grasslands Research Centre , Tennent Drive, Palmerston North 4442 , New Zealand
| | - Wade Mace
- b AgResearch Ltd., Grasslands Research Centre , Tennent Drive, Palmerston North 4442 , New Zealand
| | - Arvina Ram
- a Institute of Fundamental Sciences, Massey University , Private Bag 11 222, Palmerston North 4410 , New Zealand
| | - Yonathan Lukito
- a Institute of Fundamental Sciences, Massey University , Private Bag 11 222, Palmerston North 4410 , New Zealand
| | - Pierre-Yves Dupont
- a Institute of Fundamental Sciences, Massey University , Private Bag 11 222, Palmerston North 4410 , New Zealand
| | - Linda J Johnson
- b AgResearch Ltd., Grasslands Research Centre , Tennent Drive, Palmerston North 4442 , New Zealand
| | - D Barry Scott
- a Institute of Fundamental Sciences, Massey University , Private Bag 11 222, Palmerston North 4410 , New Zealand
| | - Austen R D Ganley
- c School of Biological Sciences, University of Auckland , Private Bag 92019, Auckland 1142 , New Zealand
| | - Murray P Cox
- a Institute of Fundamental Sciences, Massey University , Private Bag 11 222, Palmerston North 4410 , New Zealand
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Yan K, Yanling J, Xianghui S, Lihui Z, Wei L, Hanshou Y, Zhiwei W. Taxonomy ofNeotyphodiumendophytes of Chinese nativeRoegneriaplants. Mycologia 2017; 101:211-9. [DOI: 10.3852/08-018] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | | | | | | | | | | | - Wang Zhiwei
- College of Life Sciences, Nanjing Agricultural University, Nanjing, China 210095
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11
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Chen YG, Ji YL, Yu HS, Wang ZW. A new Neotyphodium species from Festuca parvigluma Steud. grown in China. Mycologia 2017; 101:681-5. [DOI: 10.3852/08-181] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | | | | | - Zhi-wei Wang
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
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Ji YL, Zhan LH, Kang Y, Sun XH, Yu HS, Wang ZW. A new stromata-producingNeotyphodiumspecies symbiotic with clonal grassCalamagrostis epigeios(L.) Roth. grown in China. Mycologia 2017; 101:200-5. [DOI: 10.3852/08-044] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | | | | | | | | | - Zhi-wei Wang
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
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Iannone LJ, Cabral D, Schardl CL, Rossi MS. Phylogenetic divergence, morphological and physiological differences distinguish a newNeotyphodiumendophyte species in the grassBromus auleticusfrom South America. Mycologia 2017; 101:340-51. [DOI: 10.3852/08-156] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - Daniel Cabral
- Laboratorio de Micología, Departamento Biodiversidad y Biología Experimental, PRHIDEB-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina
| | | | - María Susana Rossi
- Laboratorio de Fisiología y Biología Molecular, Departamento Fisiología, Biología Molecular y Celular, IFIBYME-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina
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Xia C, Li N, Zhang X, Feng Y, Christensen MJ, Nan Z. An Epichloë endophyte improves photosynthetic ability and dry matter production of its host Achnatherum inebrians infected by Blumeria graminis under various soil water conditions. FUNGAL ECOL 2016. [DOI: 10.1016/j.funeco.2016.04.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Zhang X, Ren AZ, Wei YK, Lin F, Li C, Liu ZJ, Gao YB. Taxonomy, diversity and origins of symbiotic endophytes ofAchnatherum sibiricumin the Inner Mongolia Steppe of China. FEMS Microbiol Lett 2009; 301:12-20. [DOI: 10.1111/j.1574-6968.2009.01789.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Young CA, Tapper BA, May K, Moon CD, Schardl CL, Scott B. Indole-diterpene biosynthetic capability of epichloë endophytes as predicted by ltm gene analysis. Appl Environ Microbiol 2009; 75:2200-11. [PMID: 19181837 PMCID: PMC2663189 DOI: 10.1128/aem.00953-08] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2008] [Accepted: 01/20/2009] [Indexed: 11/20/2022] Open
Abstract
Bioprotective alkaloids produced by Epichloë and closely related asexual Neotyphodium fungal endophytes protect their grass hosts from insect and mammalian herbivory. One class of these compounds, known for antimammalian toxicity, is the indole-diterpenes. The LTM locus of Neotyphodium lolii (Lp19) and Epichloë festuce (Fl1), required for the biosynthesis of the indole-diterpene lolitrem, consists of 10 ltm genes. We have used PCR and Southern analysis to screen a broad taxonomic range of 44 endophyte isolates to determine why indole-diterpenes are present in so few endophyte-grass associations in comparison to that of the other bioprotective alkaloids, which are more widespread among the endophtyes. All 10 ltm genes were present in only three epichloë endophytes. A predominance of the asexual Neotyphodium spp. examined contained 8 of the 10 ltm genes, with only one N. lolii containing the entire LTM locus and the ability to produce lolitrems. Liquid chromatography-tandem mass spectrometry profiles of indole-diterpenes from a subset of endophyte-infected perennial ryegrass showed that endophytes that contained functional genes present in ltm clusters 1 and 2 were capable of producing simple indole-diterpenes such as paspaline, 13-desoxypaxilline, and terpendoles, compounds predicted to be precursors of lolitrem B. Analysis of toxin biosynthesis genes by PCR now enables a diagnostic method to screen endophytes for both beneficial and detrimental alkaloids and can be used as a resource for screening isolates required for forage improvement.
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Affiliation(s)
- Carolyn A Young
- Institute of Molecular BioSciences, Massey University, Private Bag 11 222, Palmerston North, New Zealand.
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