Development of genetic maps of the citrus varieties ‘Murcott’ tangor and ‘Pêra’ sweet orange by using fluorescent AFLP markers

During the spring of 2006, the main Syrian citrus-growing areas of Lattakia (Jableh, Aledyye, Eseelya, Siano, and Hresoon provinces) and Tartous (Almintar, Aljammase, Karto, Majdaloonelbahr, Yahmour, Amreet, Althawra, and Safita provinces) were surveyed to assess the presence of Citrus tristeza virus (CTV). Eight nurseries (approximately 130 plants per nursery), two budwood source fields (approximately 230 trees per field), and 19 groves (approximately 60 trees per grove) containing the main citrus varieties were visually inspected and sampled for serological assays. The hierarchical sampling method was carried out in each selected grove (2). Infected samples were collected from two nurseries, two budwood source fields, and six groves. Stems and leaf petioles from nursery trees and flower explants from the groves were collected and analyzed for CTV by direct tissue blot immunoassay (DTBIA) with the commercial kit from Plantprint (Valencia, Spain). Of 2,653 samples tested, 89 (4%) CTV-infected plants were detected. Five citrus varieties were found to be infected and Meyer lemon (Citrus limon ‘Meyer’) had the highest incidence at 16%. Numerous sweet orange varieties (Citrus sinensis L.) were found to be highly infected in the field, but only the Washington navel sweet orange was found to be infected in the nurseries. No clear CTV symptoms were observed during the survey. Samples that were positive for CTV by DTBIA were also positive by biological indexing on Mexican lime (C. aurantifolia) and immunocapture-reverse transcription-PCR as described by Nolasco et al. (3). Coat protein gene sequences obtained from five selected clones of a Syrian CTV isolate (GenBank Accession No. EU626555) showed more than 99 and 98% nucleotide sequence identity to a Jordanian CTV isolate (GenBank Accession No. AY550252) and the VT isolate (GenBank Accession No. U56902), respectively. Almost all infected samples induced moderate vein clearing symptoms when grafted to Mexican lime. Symptoms of vein clearing, leaf cupping, stunting, and stem pitting on Mexican lime were induced by graft transmission of CTV from one Valencia sample from the Tartous area. The viral inoculum is widely and randomly distributed in commercial groves, especially in the southern Tartous area and in some nurseries. To our knowledge, this is the first report of CTV in Syria. However, CTV was reported from the neighboring citrus-growing countries of Lebanon, Turkey, and Jordan (1), and the severe seedling yellows strain is present in this area, which poses a potential threat to Syrian citriculture. References: (1) G. H. Anfoka et al. Phytopathol. Mediterr. 44:17, 2005. (2) G. Hughes and T. R. Gottwald, Phytopathology 88:715, 1998. (3) G. Nolasco et al. Eur. J. Plant Pathol. 108:293, 2002.

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Genetic mapping of resistance factors to Phytophthora palmivora in cocoa

Genome ◽

10.1139/g00-099 ◽

2001 ◽

Vol 44 (1) ◽

pp. 79-85 ◽

Cited By ~ 17

Author(s):

M -H Flament ◽

I Kebe ◽

D Clément ◽

I Pieretti ◽

A -M Risterucci ◽

...

Keyword(s):

Quantitative Trait ◽

Natural Infection ◽

Genetic Maps ◽

Aflp Markers ◽

Phytophthora Palmivora ◽

Good Prediction ◽

Linkage Groups ◽

Genetic Determination ◽

Total Length ◽

Adult Trees

Phytophthora palmivora causes pod rot, a serious disease on cocoa widespread throughout the producing regions. In order to ascertain the genetic determination of cocoa resistance to P. palmivora, a study was carried out on two progenies derived from crosses between a heterozygous, moderately resistant Forastero clone, T60/887, and two closely related and highly susceptible Forastero clones, one completely homozygous, IFC2, and one partially heterozygous, IFC5. The cumulative size of both progenies was 112 individuals. Plants were subjected to natural and artificial inoculation of P. palmivora in Côte d'Ivoire. The genetic maps of T60/887 and of IFC5 were constructed using amplified fragment length polymorphism (AFLP) markers and microsatellites. The map of T60/887 comprised 198 markers assembled in 11 linkage groups and representing a total length of 793 cM. The map of IFC5 comprised 55 AFLP markers that were assembled into six linkage groups for a total length of 244 cM. Ratio of rotten over total number of fruit under natural infection was measured for each tree over two harvests. Artificial inoculations were performed on leaves and pods. These tests were weakly correlated with the pod rot rate in the field. Five quantitative trait loci (QTLs) of resistance were detected for T60/887 but none were common between the three traits measured. Stability and reliability of the experimental procedures are discussed and revealed the difficult use of these artificial tests on adult trees for a good prediction of field resistance.Key words: Theobroma cacao, Phytophthora palmivora, cocoa black pod disease, genetic map, quantitative trait locus (QTL).

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Citrus Responses to Xylella fastidiosa Infection

Plant Disease ◽

10.1094/pdis-10-11-0868-re ◽

2012 ◽

Vol 96 (9) ◽

pp. 1245-1249 ◽

Cited By ~ 18

Author(s):

A. L. Garcia ◽

S. C. Z. Torres ◽

M. Heredia ◽

S. A. Lopes

Keyword(s):

Sweet Orange ◽

Control Strategies ◽

Xylella Fastidiosa ◽

Symptom Expression ◽

Xylem Anatomy ◽

Citrus Species ◽

Mechanisms Of Resistance ◽

Xylem Structure ◽

Citrus Varieties ◽

Inoculum Pressure

The xylem-limited bacterium Xylella fastidosa causes the widely disseminated citrus variegated chlorosis disease (CVC). In Brazil, CVC has been known for more than 20 years and affects only sweet orange. Lime and mandarin have remained free of symptoms despite the high inoculum pressure. Knowing the mechanisms underlying this apparent resistance is important to devise new disease control strategies. The reaction of commercial sweet orange (‘Caipira’, ‘Natal’, ‘Pêra’, and ‘Valencia’), lime (Mexican and Persian), mandarin (‘Cleopatra’, ‘Cravo’, ‘Ponkan’, and ‘Sunki’), and the acid citrus species Rangpur to X. fastidiosa was compared in artificially inoculated seedlings, which were assessed for symptom expression, pathogen isolation, and the amount of apparently occluded xylem vessels in cross-sectioned leaf petioles. Only the sweet orange expressed typical CVC symptoms, varying from 53.8% in Valencia to 63.0% in Caipira. Average percentages of positive isolations (pi) and occluded vessels (ov) were higher in sweet orange (pi= 59.2 to 75.0; ov = 10.7 to 25.8) than mandarin (pi = 2.3 to 16.3; ov = 1.4 to 4.0), lime (pi = 0 to 5.4; ov = 0 to 2.1), or Rangpur (pi = 1,9; ov = 1.1). There were no obvious differences in xylem anatomy among all citrus varieties, suggesting that the mechanisms of resistance to CVC are not related to any physical variation in xylem structure.

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Perkembangan Penyakit Diplodia pada Tiga Isolat Botryodiplodia theobromae Path dan Peran Toksin Dalam Menekan Penyakit pada Jeruk (Citrus spp.)

Jurnal Hortikultura ◽

10.21082/jhort.v27n2.2017.p231-240 ◽

2018 ◽

Vol 27 (2) ◽

pp. 231 ◽

Cited By ~ 1

Author(s):

Mutia Erti Dwiastuti ◽

Gusti Ngurah Ketut Budiarta ◽

Loekas Soesanto

Keyword(s):

Incubation Period ◽

Sweet Orange ◽

Block Design ◽

Pathogenicity Test ◽

Botryodiplodia Theobromae ◽

Disease Symptoms ◽

Crude Toxin ◽

Randomized Block Design ◽

Necrotic Symptom ◽

Citrus Varieties

<p>Penyakit diplodia (Botryodiplodia theobromae) pada tanaman jeruk menyebar cukup luas di sentra jeruk Indonesia. Serangan parah penyakit dapat menyebabkan kematian apabila tidak dikendalikan. Tujuan penelitian adalah mengetahui patogenisitas dan peran toksin dari tiga isolat B. theobromae asal Pasuruan dan Magetan pada jeruk siam, pamelo, dan manis. Penelitian dilakukan di Laboratorium dan Rumah Kasa Balai Penelitian Tanaman Jeruk dan Buah Subtropika pada bulan November 2015 – Mei 2016. Penelitian terdiri atas dua percobaan, yaitu uji patogenisitas pada tanaman dan uji toksin kasar pada skala laboratorium. Uji patogenisitas menggunakan rancangan acak kelompok dengan sembilan kombinasi perlakuan terdiri atas tiga jenis isolat, yaitu Mg52A.1, dan Mg39.2 (asal Magetan), Ps8b (asal Pasuruan), serta tiga jenis tanaman jeruk (pamelo, siam, manis). Parameter pengamatan terdiri atas masa inkubasi, jumlah sampel nekrosis, dan luas gejala. Perlakuan pengujian toksin terdiri atas kontrol tanpa toksin, toksin kasar isolat Mg52A.1, toksin kasar isolat Mg39.2, dan toksin kasar isolat Ps8b. Aplikasi toksin dilakukan pada daun tiga varietas jeruk dengan rancangan acak lengkap, tiap perlakuan diulang tiga kali dan masing masing terdiri atas dua daun asal tanaman yang berbeda. Hasil penelitian menunjukkan bahwa masa inkubasi isolat Mg39.2 lebih cepat dibandingkan dengan isolat Mg52A.1 dan Ps8b. Ketiga isolat patogen B. theobromae asal Pasuruan dan Magetan memiliki patogenisitas yang sama dalam menimbulkan gejala penyakit pada jeruk pamelo, siam, dan manis, sedangkan toksin hanya berperan dalam mempercepat masa inkubasi.</p><p>Diplodia disease (Botryodiplodia theobromae) spread quite widely in Indonesia citrus center. Severe attacks of disease can cause death if it not controlled. The purpose of this study was determine the pathogenicity and the effect of toxins from three isolates of B. theobromae origin Pasuruan and Magetan on tangerine, pummelo, and sweet orange varieties. The study was conducted at Indonesian Citrus and Subtropical Research Institute during November 2015 – May 2016. This observation consisted of two experiments that pathogenicity test in screenhouse and crude toxin of patogen test in laboratory. Pathogenicity test used randomized block design arranged as factorial. The first factor was three isolates: Mg52A.1, Mg39.2 (from Magetan), Ps8b (from Pasuruan) and the second factor were kind of citrus (pummelo, tangerine , and sweet orange). The observation parameter consist of the incubation period, the number of necrotic samples and visual symptom. Crude toxin test treatment consists of a control test toxin without toxins, crude toxin Mg52A.1, crude toxin Mg39.2 toxin, crude toxin Ps8b. Application toxin carried out on the three leaf varieties of oranges. Each treatment was repeated three times and each consists of two leaves of different varieties. The results showed that the incubation period Mg39.2 isolates faster than two other isolates. Infection with different isolates and treatment of different citrus varieties shows that it did not different significantly in causing disease symptom of diplodia. Similarly result on crude toxin treatment with three isolates on three varieties showed that it were not different necrotic symptom. Thus the three isolates of pathogens B.theobromae origin from Pasuruan and Magetan have the same pathogenicity in causing disease symptoms in citrus pummelo, tangerine, and sweet orange. Toxin only play a role in accelerating the incubation period.</p>

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Detection of Quantitative Trait Loci and Inheritance of Root-knot Nematode Resistance in Sweetpotato

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.133.6.844 ◽

2008 ◽

Vol 133 (6) ◽

pp. 844-851 ◽

Cited By ~ 19

Author(s):

Jim C. Cervantes-Flores ◽

G. Craig Yencho ◽

Kenneth V. Pecota ◽

Bryon Sosinski ◽

Robert O.M. Mwanga

Keyword(s):

Quantitative Trait Loci ◽

Quantitative Trait ◽

Ipomoea Batatas ◽

The United States ◽

Genetic Maps ◽

Aflp Markers ◽

Root Knot Nematodes ◽

Egg Masses ◽

Positive Effects ◽

Trait Loci

Resistance to root-knot nematodes [Meloidogyne incognita (Kofoid & White) Chitwood] in sweetpotato [Ipomoea batatas (L.) Lam.] was studied in a mapping population consisting of 240 progeny derived from a cross between ‘Beauregard’, the predominant cultivar in the United States, and ‘Tanzania’, an African landrace. Quantitative trait loci (QTL) analyses to locate markers associated with resistance to root-knot nematodes (RKN) were performed using genetic maps based on parental segregation in ‘Beauregard’ and ‘Tanzania’ consisting of 726 and 947 single-dose amplified fragment length polymorphism (AFLP) markers, respectively. RKN resistance in the progeny was highly skewed with most of the progeny exhibiting medium to high levels of resistance. Single-point analysis of variance and interval mapping revealed seven consistently significant QTL in ‘Tanzania’ and two significant QTL in ‘Beauregard’. In ‘Tanzania’, three QTL were associated with reduction in resistance as measured by the number of RKN egg masses and explained ≈20% of the variation. Another four QTL had positive effects on resistance and explained ≈21% of the variation. Other minor QTL explained ≈2% or less of the variation but were not always consistent across geographical locations. In ‘Beauregard’, two QTL had positive effects on RKN resistance and explained ≈6% of the observed variation. Based on molecular and phenotypic data, RKN resistance in sweetpotato is hypothesized to be conferred by several genes, but at least nine AFLP markers (seven from ‘Tanzania’ and two from ‘Beauregard’) are associated with genomic regions that have the biggest effect in the number of egg masses of RKN produced in the root system.

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Effects of Molecular Distillation on the Chemical Components, Cleaning, and Antibacterial Abilities of Four Different Citrus Oils

Frontiers in Nutrition ◽

10.3389/fnut.2021.731724 ◽

2021 ◽

Vol 8 ◽

Author(s):

Feilong Yang ◽

Huijuan Zhang ◽

Guifang Tian ◽

Wenbo Ren ◽

Juan Li ◽

...

Keyword(s):

Escherichia Coli ◽

Vibrio Parahaemolyticus ◽

Molecular Distillation ◽

Sweet Orange ◽

Chemical Compounds ◽

Chemical Components ◽

Citrus Fruits ◽

Citrus Peel ◽

Effective Utilization ◽

Citrus Varieties

Essential oils (EOs) from citrus fruits are excellent aromatic resources that are used in food, cosmetics, perfume, and cleaning products. EOs extracted from four citrus varieties, sweet orange, grapefruit, mandarin, and lemon, were separated into two fractions by molecular distillation. The composition, physicochemical properties, cleaning ability, and antimicrobial activity of each EO were then systematically evaluated. The relationships between each of the aforementioned characteristics are also discussed. In keeping with the principle of “like dissolves like,” most citrus EOs show better cleaning ability than acetone and all tend to dissolve the fat-soluble pigment. The key components of citrus EOs are 1-Decanol, α-terpineol, geraniol, and linalool for the inhibition of Staphylococcus aureus, Escherichia coli, Candida albicans, and Vibrio parahaemolyticus, respectively. The findings of this study will be of significant importance for the effective utilization of citrus peel resources and in the development of future applications for citrus EOs.Chemical Compounds Studied in This Article: (+)-α-Pinene (PubChem CID: 6654); β-Phellandrene (PubChem CID: 11142); 3-Carene (PubChem CID: 26049); β-Myrcene (PubChem CID: 31253); D-Limonene (PubChem CID: 440917); γ-Terpinene (PubChem CID: 7461); Octanal (PubChem CID: 454); Decanal (PubChem CID: 8175); Linalool (PubChem CID: 6549); 1-Octanol (PubChem CID: 957); β-Citral (PubChem CID: 643779); α-Terpineol (PubChem CID: 17100); Hedycaryol (PubChem CID: 5365392); α-Citral (PubChem CID: 638011); 1-Decanol (PubChem CID: 8174); Geraniol (PubChem CID: 637566).

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Construction of high-density genetic maps and detection of QTLs associated with Huanglongbing infection in citrus

10.1101/330753 ◽

2018 ◽

Cited By ~ 2

Author(s):

Ming Huang ◽

Mikeal L. Roose ◽

Qibin Yu ◽

Dongliang Du ◽

Yi Zhang ◽

...

Keyword(s):

Sweet Orange ◽

High Density ◽

Poncirus Trifoliata ◽

Genetic Maps ◽

Trifoliate Orange ◽

High Coverage ◽

Time Points ◽

Ct Value ◽

Starting Point ◽

Liberibacter Asiaticus

AbstractNo true resistance to Huanglongbing (HLB), a citrus disease associated with infection ofCandidatusLiberibacter asiaticus (CLas), is found within commercial citrus cultivars, though trifoliate orange (Poncirus trifoliata) has been described as resistant or tolerant. Through genotyping an intergeneric F1population by Genotyping-by-Sequencing, high-density SNP-based genetic maps were constructed separately for trifoliate orange and sweet orange (Citrus sinensis). Both genetic maps exhibited high synteny and high coverage of citrus genome. After exposure to intense HLB pressure for two years, Ct value of qPCR forCLas detection in leaves throughout ten time points during the next three years was above 35 in trifoliate oranges, under 28 in sweet oranges, and ranged from 24 to 38 and exhibited obvious segregation among progenies. Phenotypic data of percentage of healthy trees showed high correlation with the Ct value. By mapping the two traits at all time points, a total of nine clusters of QTLs were detected, of which five, respectively located on LG-t7 and LG-t8 of trifoliate orange map and LG-s3, LG-s5 and LG-s9 of sweet orange map, collectively explained a major part of the phenotypic variation. This study provides a starting point for citrus breeding to support long-term control of this devastating disease.Highlight1). Constructed the first high-density genetic map for trifoliate orange (Poncirus trifoliata)2). The first report on identification of QTLs related to Huanglongbing in citrus.AbbreviationsACPAsian citrus psyllidCLasCandidatusLiberibacter asiaticuscMcentiMorgansCtCycle thresholdHLBHuanglongbingIMInterval mappingKWKruskal-WallisLGLinkage groupLODLogarithm of oddsQTLQuantitative trait locusRADRestriction site associated DNArMQMrestricted multiple QTL mappingSNPSingle nucleotide polymorphism.

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PthAW1, a transcription activator-like effector of Xanthomonas citri subsp. citri, promotes host specific immune responses

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-01-21-0026-r ◽

2021 ◽

Author(s):

Doron Teper ◽

Jin Xu ◽

Sheo Shankar Pandey ◽

Nian Wang

Keyword(s):

Host Range ◽

Sweet Orange ◽

Phenotypic Traits ◽

Ion Leakage ◽

Sequencing Analysis ◽

Transcription Activator ◽

Xanthomonas Citri ◽

Pr Genes ◽

Canker Disease ◽

Citrus Varieties

Citrus canker disease caused by Xanthomonas citri subsp. citri (Xcc) is one of the most destructive diseases in citrus. XccA causes canker disease in most commercial citrus varieties, whereas XccAW, which is genetically similar to XccA, infects only lime and alemow. Understanding the mechanism that determines the host range of pathogens is critical to investigating and utilizing host resistance. We hypothesized that XccAW would undergo mutations in genes that restrict its host range when artificially inoculated into incompatible citrus varieties. To test this hypothesis, we used an experimental evolution approach to identify phenotypic traits and genetic loci associated with the adaptation of XccAW to incompatible sweet orange. Repeated inoculation and re-isolation cycles improved the ability of three independent XccAW strains to colonize sweet orange. Adapted XccAW strains displayed increased expression of type III secretion system and effector genes. Genome sequencing analysis indicated that two of the adapted strains harbored mutations in pthAW1, a transcription activator-like effector (TALE) gene, that corresponded to the removal of one or two repeats from the central DNA binding repeat region. Introduction of the original but not the adapted pthAW1 variants into XccA abolished its ability to cause canker symptoms in sweet orange, Meyer lemon, and clementine but not in other XccAW-resistant citrus varieties. The original pthAW1, when expressed in XccA, induced ion leakage and the expression of PR genes, but had no effect on CsLOB1 expression of sweet orange. Our study has identified a novel host-specific avirulence TALE.

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Use of allele specificity of comigrating AFLP markers to align genetic maps from different potato genotypes

MGG Molecular & General Genetics ◽

10.1007/s004380050516 ◽

1997 ◽

Vol 255 (4) ◽

pp. 438-447 ◽

Cited By ~ 99

Author(s):

J. N. A. M. Rouppe van der Voort ◽

P. van Zandvoort ◽

H. J. van Eck ◽

R. T. Folkertsma ◽

R. C. B. Hutten ◽

...

Keyword(s):

Genetic Maps ◽

Aflp Markers ◽

Allele Specificity

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Molecular genetic linkage maps for allotetraploid Leymus wildryes (Gramineae: Triticeae)

Genome ◽

10.1139/g03-048 ◽

2003 ◽

Vol 46 (4) ◽

pp. 627-646 ◽

Cited By ~ 50

Author(s):

Xiaolei Wu ◽

Steven R Larson ◽

Zanmin Hu ◽

Antonio J Palazzo ◽

Thomas A Jones ◽

...

Keyword(s):

Molecular Genetic ◽

Perennial Grass ◽

Perennial Grasses ◽

Genetic Maps ◽

Aflp Markers ◽

Linkage Maps ◽

Linkage Groups ◽

Genetic Linkage Maps ◽

Leymus Triticoides ◽

Leymus Cinereus

Molecular genetic maps were constructed for two full-sib populations, TTC1 and TTC2, derived from two Leymus triticoides × Leymus cinereus hybrids and one common Leymus triticoides tester. Informative DNA markers were detected using 21 EcoRIMseI and 17 PstIMseI AFLP primer combinations, 36 anchored SSR or STS primer pairs, and 9 anchored RFLP probes. The 164-sib TTC1 map includes 1069 AFLP markers and 38 anchor loci in 14 linkage groups spanning 2001 cM. The 170-sib TTC2 map contains 1002 AFLP markers and 36 anchor loci in 14 linkage groups spanning 2066 cM. Some 488 homologous AFLP loci and 24 anchor markers detected in both populations showed similar map order. Thus, 1583 AFLP markers and 50 anchor loci were mapped into 14 linkage groups, which evidently correspond to the 14 chromosomes of allotetraploid Leymus (2n = 4x = 28). Synteny of two or more anchor markers from each of the seven homoeologous wheat and barley chromosomes was detected for 12 of the 14 Leymus linkage groups. Moreover, two distinct sets of genome-specific STS markers were identified in these allotetraploid Leymus species. These Leymus genetic maps and populations will provide a useful system to evaluate the inheritance of functionally important traits of two divergent perennial grass species.Key words: AFLP, perennial grasses, RFLP, STS, SSR.

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