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Ibrahim YE, Al-Saleh MA, Widyawan A, El Komy MH, Al Dhafer HM, Brown JK. Identification and Distribution of the ' Candidatus Liberibacter asiaticus'-Asian Citrus Psyllid Pathosystem in Saudi Arabia. PLANT DISEASE 2024; 108:1083-1092. [PMID: 37953230 DOI: 10.1094/pdis-07-23-1460-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
Citrus greening disease was first reported in Saudi Arabia during the 1970s when characteristic foliar and fruit symptoms were observed in commercial citrus groves. However, 'Candidatus Liberibacter asiaticus' (CLas) was not detected in symptomatic trees until 1981 to 1984 when CLas-like cells were observed by transmission electron microscopy in leaves collected from symptomatic citrus groves in southwestern Saudi Arabia. Despite the anticipated establishment of the CLas-Asian citrus psyllid (ACP) (Diaphorina citri Kuwayama) pathosystem, CLas presence has not been verified in suspect trees nor have ACP infestations been documented. Given the recent expansion of citrus production in Saudi Arabia, a systematic country-wide survey was carried out to determine the potential CLas distribution in the 13 citrus-growing regions of the country. Citrus trees were surveyed for the presence of CLas-psyllid vector(s) and characteristic disease symptoms in commercial and urban citrus trees. Adult psyllids collected from infested citrus trees were identified as ACP based on morphological characteristics. Real-time quantitative PCR amplification (qPCR) of the CLas β-subunit of the ribonucleotide reductase (RNR) gene from citrus leaf and fruit samples and/or ACP adults revealed that trees were positive for CLas detection in 10 of the 13 survey regions; however, CLas was undetectable in ACP adults. Phylogenetic and single nucleotide polymorphism (SNP) analyses of a PCR-amplified, cloned fragment of the CLas 16S rRNA gene (∼1.1 kbp) indicated Saudi Arabian isolates were most closely related to Florida, U.S.A., isolates. Analysis of climate variables indicated that the distribution of the ACP-CLas pathosystem observed in Saudi Arabia was consistent with published predictions of terrains most likely to support establishment.
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Affiliation(s)
- Yasser E Ibrahim
- Plant Protection Department, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia
- Bacterial Diseases Research Department, Plant Pathology Research Institute, Agricultural Research Center, Giza, Egypt
| | - Mohammed A Al-Saleh
- Plant Protection Department, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Arya Widyawan
- Plant Protection Department, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Mahmoud H El Komy
- Plant Protection Department, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Hathal M Al Dhafer
- Plant Protection Department, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Judith K Brown
- School of Plant Sciences, The University of Arizona, Tucson, AZ 85721, U.S.A
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Zheng L, Xu Q, Gong G, Liao Y, Yu M, Shabala S, Chen W, Wu W. Nicotiana tabacum as a dead-end trap for adult Diaphorina citri: A potential biological tactic for protecting citrus orchards. FRONTIERS IN PLANT SCIENCE 2023; 13:1081663. [PMID: 36684792 PMCID: PMC9853912 DOI: 10.3389/fpls.2022.1081663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is a key vector of the causal agents of Huanglongbing (HLB), a devastating disease affecting citrus almost worldwide. Nicotiana tabacum L. is an important commercial crop in China. Field observations suggested that D. citri adults die on N. tabacum leaves when grown nearby citrus orchards. In this study, the preference for and survivorship of D. citri adults on N. tabacum and their feeding behavior were investigated. The results showed that D. citri adults were attracted to N. tabacum and to the green leaf volatiles (GLVs) (Z)-3-hexenol and (E)-2-hexenol. The survival of D. citri adults on N. tabacum was less than 30 h, which was shorter than that for adults without food (35 h) and on a suitable host Murraya exotica L. (29 days). Electrical penetration graph (EPG) recordings revealed that the pathway phase of D. citri on N. tabacum leaves consisted of four waveforms-the non-probing phase (NP), the pathway phase (PP, including intercellular probing of activity in the phloem (C) and phloem penetration (D)), phloem salivation (E1), and phloem ingestion (E2). Diaphorina citri only secreted saliva and ingested sap from phloem on N. tabacum leaves and spent the longest duration in phloem sap ingestion (E2). Moreover, L-nicotine, an important defense compound against insects in N. tabacum plants, was highly toxic to D. citri. These results suggested that N. tabacum plants could help to sustainably control the spread of D. citri and HLB when growing in and around citrus orchards.
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Affiliation(s)
- Lixia Zheng
- International Research Center for Environmental Membrane Biology and Department of Horticulture, Foshan University, Foshan, China
| | - Qianqian Xu
- Laboratory of Insect Ecology, South China Agricultural University, Guangzhou, China
| | - Gu Gong
- Laboratory of Insect Ecology, South China Agricultural University, Guangzhou, China
| | - Yonglin Liao
- Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Min Yu
- International Research Center for Environmental Membrane Biology and Department of Horticulture, Foshan University, Foshan, China
| | - Sergey Shabala
- International Research Center for Environmental Membrane Biology and Department of Horticulture, Foshan University, Foshan, China
| | - Wensheng Chen
- International Research Center for Environmental Membrane Biology and Department of Horticulture, Foshan University, Foshan, China
| | - Weijian Wu
- Laboratory of Insect Ecology, South China Agricultural University, Guangzhou, China
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Ghosh D, Kokane S, Savita BK, Kumar P, Sharma AK, Ozcan A, Kokane A, Santra S. Huanglongbing Pandemic: Current Challenges and Emerging Management Strategies. PLANTS (BASEL, SWITZERLAND) 2022; 12:plants12010160. [PMID: 36616289 PMCID: PMC9824665 DOI: 10.3390/plants12010160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 12/06/2022] [Accepted: 12/07/2022] [Indexed: 05/09/2023]
Abstract
Huanglongbing (HLB, aka citrus greening), one of the most devastating diseases of citrus, has wreaked havoc on the global citrus industry in recent decades. The culprit behind such a gloomy scenario is the phloem-limited bacteria "Candidatus Liberibacter asiaticus" (CLas), which are transmitted via psyllid. To date, there are no effective long-termcommercialized control measures for HLB, making it increasingly difficult to prevent the disease spread. To combat HLB effectively, introduction of multipronged management strategies towards controlling CLas population within the phloem system is deemed necessary. This article presents a comprehensive review of up-to-date scientific information about HLB, including currently available management practices and unprecedented challenges associated with the disease control. Additionally, a triangular disease management approach has been introduced targeting pathogen, host, and vector. Pathogen-targeting approaches include (i) inhibition of important proteins of CLas, (ii) use of the most efficient antimicrobial or immunity-inducing compounds to suppress the growth of CLas, and (iii) use of tools to suppress or kill the CLas. Approaches for targeting the host include (i) improvement of the host immune system, (ii) effective use of transgenic variety to build the host's resistance against CLas, and (iii) induction of systemic acquired resistance. Strategies for targeting the vector include (i) chemical and biological control and (ii) eradication of HLB-affected trees. Finally, a hypothetical model for integrated disease management has been discussed to mitigate the HLB pandemic.
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Affiliation(s)
- Dilip Ghosh
- Plant Virology Laboratory, ICAR-Central Citrus Research Institute, Nagpur 440033, India
- Correspondence: (D.G.); (A.K.S.); (S.S.)
| | - Sunil Kokane
- Plant Virology Laboratory, ICAR-Central Citrus Research Institute, Nagpur 440033, India
| | - Brajesh Kumar Savita
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee 247667, India
| | - Pranav Kumar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee 247667, India
| | - Ashwani Kumar Sharma
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee 247667, India
- Correspondence: (D.G.); (A.K.S.); (S.S.)
| | - Ali Ozcan
- Vocational School of Technical Sciences, Karamanoglu Mehmetbey University, 70200 Karaman, Turkey
- Scientific and Technological Studies Application and Research Center, Karamanoglu Mehmetbey University, 70200 Karaman, Turkey
| | - Amol Kokane
- Plant Virology Laboratory, ICAR-Central Citrus Research Institute, Nagpur 440033, India
| | - Swadeshmukul Santra
- Departments of Chemistry, Nano Science Technology Center, and Burnett School of Biomedical Sciences, University of Central Florida, Orlando, FL 32816, USA
- Correspondence: (D.G.); (A.K.S.); (S.S.)
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Eduardo WI, Miranda MP, Volpe HXL, Garcia RB, Girardi EA, Alquezar B, Ruiz AE, Peña L. Resistance of True Citrus species to Diaphorina citri. PEST MANAGEMENT SCIENCE 2022; 78:4783-4792. [PMID: 35900363 DOI: 10.1002/ps.7098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/30/2022] [Accepted: 07/28/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Host genetic resistance is a promising strategy for the management of Diaphorina citri Kuwayama (Hemiptera: Psyllidae), and consequently Huanglongbing (HLB). To date, no study has investigated the resistance to D. citri in the clonal and vegetatively propagated plants of the Microcitrus, Eremocitrus, and Atalantia genera. This study assesses Near and True Citrus genotype antixenosis and antibiosis against D. citri, with trichome density and volatile emission as possible mechanisms of resistance. RESULTS All genotypes were oviposited by D. citri, however, 8 of 14 genotypes were less oviposited than Citrus × sinensis 'Valencia' (susceptible control). Diaphorina citri nymphs had lower nymphal viability in E. glauca (31%) and M. warburgiana (58%) than that in Citrus × sinensis (77%). The behavioral assay showed that 30% of D. citri nymphs in the last instars evaded E. glauca shoots, whereas no nymphs evaded Citrus × sinensis shoots. A higher trichome density was observed in E. glauca shoots compared to the other genotypes. Chemical analysis revealed differences in the volatile profiles of E. glauca and Citrus × sinensis. CONCLUSION Eremocitrus glauca and M. warburgiana genotypes were more resistant to D. citri than Citrus × sinensis. Higher trichome density in the shoots may negatively influence the development of D. citri nymphs. Eremocitrus glauca volatiles may also be involved in their resistance to D. citri. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Wellington Ivo Eduardo
- Department of Research and Development, Fund for Citrus Protection - Fundecitrus, Araraquara, Brazil
| | - Marcelo Pedreira Miranda
- Department of Research and Development, Fund for Citrus Protection - Fundecitrus, Araraquara, Brazil
| | | | - Rafael Brandão Garcia
- Department of Research and Development, Fund for Citrus Protection - Fundecitrus, Araraquara, Brazil
| | - Eduardo Augusto Girardi
- Department of Research and Development, Fund for Citrus Protection - Fundecitrus, Araraquara, Brazil
- Brazilian Agricultural Research Corporation - Embrapa, Embrapa Cassava & Fruits, Cruz das Almas, Brazil
| | - Berta Alquezar
- Instituto de Biologia Molecular y Celular de Plantas - Consejo Superior de Investigaciones Científicas (IBMCP-CSIC), Universidad Politécnica de Valencia, Valencia, Spain
| | - Ana Espinosa Ruiz
- Instituto de Biologia Molecular y Celular de Plantas - Consejo Superior de Investigaciones Científicas (IBMCP-CSIC), Universidad Politécnica de Valencia, Valencia, Spain
| | - Leandro Peña
- Instituto de Biologia Molecular y Celular de Plantas - Consejo Superior de Investigaciones Científicas (IBMCP-CSIC), Universidad Politécnica de Valencia, Valencia, Spain
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Alves MN, Raiol-Junior LL, Girardi EA, Miranda M, Wulff NA, Carvalho EV, Lopes SA, Ferro JA, Ollitrault P, Peña L. Insight into resistance to ' Candidatus Liberibacter asiaticus,' associated with Huanglongbing, in Oceanian citrus genotypes. FRONTIERS IN PLANT SCIENCE 2022; 13:1009350. [PMID: 36160987 PMCID: PMC9500433 DOI: 10.3389/fpls.2022.1009350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 08/22/2022] [Indexed: 06/16/2023]
Abstract
Huanglongbing (HLB), the most destructive citrus disease, is associated with unculturable, phloem-limited Candidatus Liberibacter species, mainly Ca. L. asiaticus (Las). Las is transmitted naturally by the insect Diaphorina citri. In a previous study, we determined that the Oceanian citrus relatives Eremocitrus glauca, Microcitrus warburgiana, Microcitrus papuana, and Microcitrus australis and three hybrids among them and Citrus were full-resistant to Las. After 2 years of evaluations, leaves of those seven genotypes remained Las-free even with their susceptible rootstock being infected. However, Las was detected in their stem bark above the scion-rootstock graft union. Aiming to gain an understanding of the full-resistance phenotype, new experiments were carried out with the challenge-inoculated Oceanian citrus genotypes through which we evaluated: (1) Las acquisition by D. citri fed onto them; (2) Las infection in sweet orange plants grafted with bark or budwood from them; (3) Las infection in sweet orange plants top-grafted onto them; (4) Las infection in new shoots from rooted plants of them; and (5) Las infection in new shoots of them after drastic back-pruning. Overall, results showed that insects that fed on plants from the Oceanian citrus genotypes, their canopies, new flushes, and leaves from rooted cuttings evaluated remained quantitative real-time polymerase chain reaction (qPCR)-negative. Moreover, their budwood pieces were unable to infect sweet orange through grafting. Furthermore, sweet orange control leaves resulted infected when insects fed onto them and graft-receptor susceptible plants. Genomic and morphological analysis of the Oceanian genotypes corroborated that E. glauca and M. warburgiana are pure species while our M. australis accession is an M. australis × M. inodora hybrid and M. papuana is probably a M. papuana × M. warburgiana hybrid. E. glauca × C. sinensis hybrid was found coming from a cross between E. glauca and mandarin or tangor. Eremocitrus × Microcitrus hybrid is a complex admixture of M. australasica, M. australis, and E. glauca while the last hybrid is an M. australasica × M. australis admixture. Confirmation of consistent full resistance in these genotypes with proper validation of their genomic parentages is essential to map properly genomic regions for breeding programs aimed to generate new Citrus-like cultivars yielding immunity to HLB.
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Affiliation(s)
- Mônica N. Alves
- Fundo de Defesa da Citricultura, Araraquara, Brazil
- Faculdade de Ciências Agrárias e Veterinárias (FCAV), Universidade Estadual Paulista (UNESP), Jaboticabal, Brazil
| | - Laudecir L. Raiol-Junior
- Fundo de Defesa da Citricultura, Araraquara, Brazil
- Empresa Brasileira de Pesquisa Agropecuária, Cruz das Almas, Brazil
| | - Eduardo A. Girardi
- Fundo de Defesa da Citricultura, Araraquara, Brazil
- Empresa Brasileira de Pesquisa Agropecuária, Cruz das Almas, Brazil
| | - Maéva Miranda
- CIRAD, UMR AGAP Institut, Montpellier, France
- AGAP Institut, Univ. Montpellier, CIRAD, INRAE, Institut Agro, Montpellier, France
| | | | - Everton V. Carvalho
- Fundo de Defesa da Citricultura, Araraquara, Brazil
- Empresa Brasileira de Pesquisa Agropecuária, Cruz das Almas, Brazil
| | | | - Jesus A. Ferro
- Faculdade de Ciências Agrárias e Veterinárias (FCAV), Universidade Estadual Paulista (UNESP), Jaboticabal, Brazil
| | - Patrick Ollitrault
- CIRAD, UMR AGAP Institut, Montpellier, France
- AGAP Institut, Univ. Montpellier, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Leandro Peña
- Fundo de Defesa da Citricultura, Araraquara, Brazil
- Instituto de Biologia Molecular y Celular de Plantas – Consejo Superior de Investigaciones Científicas, Universidad Politécnica de Valencia, Valencia, Spain
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Weber KC, Mahmoud LM, Stanton D, Welker S, Qiu W, Grosser JW, Levy A, Dutt M. Insights into the mechanism of Huanglongbing tolerance in the Australian finger lime ( Citrus australasica). FRONTIERS IN PLANT SCIENCE 2022; 13:1019295. [PMID: 36340410 PMCID: PMC9634478 DOI: 10.3389/fpls.2022.1019295] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 09/22/2022] [Indexed: 05/13/2023]
Abstract
The Australian finger lime (Citrus australasica) is tolerant to Huanglongbing (HLB; Citrus greening). This species can be utilized to develop HLB tolerant citrus cultivars through conventional breeding and biotechnological approaches. In this report, we conducted a comprehensive analysis of transcriptomic data following a non-choice infection assay to understand the CaLas tolerance mechanisms in the finger lime. After filtering 3,768 differentially expressed genes (DEGs), 2,396 were downregulated and 1,372 were upregulated in CaLas-infected finger lime compared to CaLas-infected HLB-susceptible 'Valencia' sweet orange. Comparative analyses revealed several DEGs belonging to cell wall, β-glucanase, proteolysis, R genes, signaling, redox state, peroxidases, glutathione-S-transferase, secondary metabolites, and pathogenesis-related (PR) proteins categories. Our results indicate that the finger lime has evolved specific redox control systems to mitigate the reactive oxygen species and modulate the plant defense response. We also identified candidate genes responsible for the production of Cys-rich secretory proteins and Pathogenesis-related 1 (PR1-like) proteins that are highly upregulated in infected finger lime relative to noninfected and infected 'Valencia' sweet orange. Additionally, the anatomical analysis of phloem and stem tissues in finger lime and 'Valencia' suggested better regeneration of phloem tissues in finger lime in response to HLB infection. Analysis of callose formation following infection revealed a significant difference in the production of callose plugs between the stem phloem of CaLas+ 'Valencia' sweet orange and finger lime. Understanding the mechanism of resistance will help the scientific community design strategies to protect trees from CaLas infection and assist citrus breeders in developing durable HLB tolerant citrus varieties.
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Affiliation(s)
- Kyle C. Weber
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, United States
| | - Lamiaa M. Mahmoud
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, United States
- Pomology Department, Faculty of Agriculture, Mansoura University, Mansoura, Egypt
| | - Daniel Stanton
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, United States
| | - Stacy Welker
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, United States
| | - Wenming Qiu
- Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Jude W. Grosser
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, United States
| | - Amit Levy
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, United States
| | - Manjul Dutt
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, United States
- *Correspondence: Manjul Dutt,
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Lu H, Fang X, Wu F, Ouyang G. Adaptability and 'Candidatus Liberibacter asiaticus' titres of Diaphorina citri adults on three weed species in China. PEST MANAGEMENT SCIENCE 2021; 77:3216-3223. [PMID: 33751790 DOI: 10.1002/ps.6360] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 02/19/2021] [Accepted: 03/09/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Diaphorina citri is a vector of 'Candidatus Liberibacter asiaticus' (CLas), which is associated with citrus huanglongbing (HLB). In this study, the adaptability and CLas titres of D. citri adults on three weed species, namely, Ageratum conyzoides, Solanum nigrum and Praxelis clematidea, which are widely distributed in citrus orchards in China, were determined. RESULTS D. citri selected S. nigrum preferentially over the other weed species. The longest survival times of D. citri adults on A. conyzoides, S. nigrum and P. clematidea were 48, 41 and 11 days, respectively. On S. nigrum, the survivorship of females was significantly higher than that of males. The CLas titres of D. citri adults feeding on the three weeds for 1 week increased significantly during autumn but did not change significantly during spring. Conversely, the titres of adults on citrus increased significantly during spring but did not change significantly during autumn. CONCLUSION D. citri exhibited different adaptabilities to the three weed species, but the CLas titres of D. citri adults did not decrease on any of the weeds. These results suggested that the three weed species could help dispersing of D. citri and transmission of CLas while ideal host conditions were scarce or absent. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Huilin Lu
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, Guangdong Academy of Sciences, Guangzhou, China
| | - Xiaoduan Fang
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, Guangdong Academy of Sciences, Guangzhou, China
| | - Fengnian Wu
- School of Food Engineering and Biotechnology, Hanshan Normal University, Chaozhou, China
| | - Gecheng Ouyang
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, Guangdong Academy of Sciences, Guangzhou, China
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Alquézar B, Carmona L, Bennici S, Peña L. Engineering of citrus to obtain huanglongbing resistance. Curr Opin Biotechnol 2021; 70:196-203. [PMID: 34198205 DOI: 10.1016/j.copbio.2021.06.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 06/04/2021] [Accepted: 06/07/2021] [Indexed: 12/23/2022]
Abstract
Huanglongbing (HLB) disease is threatening the sustainability of citriculture in affected regions because of its rapid spread and the severity of the symptoms it induces. Herein, we summarise the main research findings that can be exploited to develop HLB-resistant cultivars. A major bottleneck has been the lack of a system for the ex vivo cultivation of HLB-associated bacteria (CLs) in true plant hosts, which precludes the evaluation of target genes/metabolites in reliable plant/pathogen/vector environments. With regard to HLB vectors, several biotechnologies which have been proven in laboratory settings to be effective for insect control are presented. Finally, new genotypes that are resistant to CLs or their insect vectors are described, and the most relevant strategies for fighting HLB are highlighted.
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Affiliation(s)
- Berta Alquézar
- Laboratório de Biotecnologia Vegetal, Pesquisa & Desenvolvimento, Fundo de Defesa da Citricultura (Fundecitrus), Vila Melhado, 14807-040 Araraquara, São Paulo, Brazil; Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC)-Universidad Politécnica de Valencia (UPV), 46022 Valencia, Spain
| | - Lourdes Carmona
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC)-Universidad Politécnica de Valencia (UPV), 46022 Valencia, Spain
| | - Stefania Bennici
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC)-Universidad Politécnica de Valencia (UPV), 46022 Valencia, Spain
| | - Leandro Peña
- Laboratório de Biotecnologia Vegetal, Pesquisa & Desenvolvimento, Fundo de Defesa da Citricultura (Fundecitrus), Vila Melhado, 14807-040 Araraquara, São Paulo, Brazil; Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas (CSIC)-Universidad Politécnica de Valencia (UPV), 46022 Valencia, Spain.
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Martini X, Malfa K, Stelinski LL, Iriarte FB, Paret ML. Distribution, Phenology, and Overwintering Survival of Asian Citrus Psyllid (Hemiptera: Liviidae), in Urban and Grove Habitats in North Florida. JOURNAL OF ECONOMIC ENTOMOLOGY 2020; 113:1080-1087. [PMID: 31982907 DOI: 10.1093/jee/toaa011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Indexed: 06/10/2023]
Abstract
Cold hardy citrus is an emerging industry in north Florida. However, it is under the threat of Candidatus Liberibacter asiaticus (CLas), the agent of the citrus disease huanglongbing. Distribution and phenology of the Asian citrus psyllid, Diaphorina citri (Kuwayama), the vector of CLas, was investigated over a 2-year sampling period in north Florida. Diaphorina citri was only found in backyard and ornamental citrus along the Gulf of Mexico, and was not observed in cultivated citrus groves during the 2 years (2017-2018) of the survey. Diaphorina citri population peaks occurred approximately 2 mo later than in central Florida with major population peaks occurring in July. The number of D. citri adults was significantly higher on CLas infected than uninfected citrus trees, whereas more nymphs were found on uninfected trees. Most D. citri were negative for CLas except in Franklin county where both infected trees and psyllids were found. We were able to find adult D. citri during all winter months, despite temperatures as low as -5.5°C. During two consecutive winters, we conducted experiments to determine D. citri cold hardiness by caging D. citri under ambient conditions in mid-November and assessing survivors in the following spring. In 2018, approximately 21%, of D. citri adults survived overwintering whereas 16% survived in 2019 despite lower temperature in 2018 than in 2019. As we are at the earliest stage of HLB infestation, management of D. citri and CLas in north Florida should focus on removal of CLas-infected trees to reduce the reservoir of pathogen.
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Affiliation(s)
- Xavier Martini
- Entomology and Nematology Department, North Florida Research and Education Center, University of Florida, Quincy, FL
| | - Kathi Malfa
- Entomology and Nematology Department, North Florida Research and Education Center, University of Florida, Quincy, FL
| | - Lukasz L Stelinski
- Entomology and Nematology Department, Citrus Research and Education Center, Lake Alfred, FL
| | - Fanny B Iriarte
- Plant Pathology Department, North Florida Research and Education Center, Quincy, FL
| | - Mathews L Paret
- Plant Pathology Department, North Florida Research and Education Center, Quincy, FL
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Alves MN, Lopes SA, Raiol-Junior LL, Wulff NA, Girardi EA, Ollitrault P, Peña L. Resistance to ' Candidatus Liberibacter asiaticus,' the Huanglongbing Associated Bacterium, in Sexually and/or Graft-Compatible Citrus Relatives. FRONTIERS IN PLANT SCIENCE 2020; 11:617664. [PMID: 33488659 PMCID: PMC7820388 DOI: 10.3389/fpls.2020.617664] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/10/2020] [Indexed: 05/14/2023]
Abstract
Huanglongbing (HLB) is the most destructive, yet incurable disease of citrus. Finding sources of genetic resistance to HLB-associated 'Candidatus Liberibacter asiaticus' (Las) becomes strategic to warrant crop sustainability, but no resistant Citrus genotypes exist. Some Citrus relatives of the family Rutaceae, subfamily Aurantioideae, were described as full-resistant to Las, but they are phylogenetically far, thus incompatible with Citrus. Partial resistance was indicated for certain cross-compatible types. Moreover, other genotypes from subtribe Citrinae, sexually incompatible but graft-compatible with Citrus, may provide new rootstocks able to restrict bacterial titer in the canopy. Use of seedlings from monoembryonic species and inconsistencies in previous reports likely due to Las recalcitrance encouraged us to evaluate more accurately these Citrus relatives. We tested for Las resistance a diverse collection of graft-compatible Citrinae species using an aggressive and consistent challenge-inoculation and evaluation procedure. Most Citrinae species examined were either susceptible or partially resistant to Las. However, Eremocitrus glauca and Papua/New Guinea Microcitrus species as well as their hybrids and those with Citrus arose here for the first time as full-resistant, opening the way for using these underutilized genotypes as Las resistance sources in breeding programs or attempting using them directly as possible new Las-resistant Citrus rootstocks or interstocks.
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Affiliation(s)
| | | | | | | | | | - Patrick Ollitrault
- Centre de Coopération Internationale en Recherche Agronomique pour le Développement, BIOS Department, UPR amélioration génétique des espèces à multiplication végétative, Montpellier, France
| | - Leandro Peña
- Fundo de Defesa da Citricultura, Araraquara, Brazil
- Instituto de Biologia Molecular y Celular de Plantas – Consejo Superior de Investigaciones Científicas, Universidad Politécnica de Valencia, Valencia, Spain
- *Correspondence: Leandro Peña, ;
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