scholarly journals First Report of a 16SrXIV Group Phytoplasma Associated With Witches’-Broom Disease of Acid Lime (Citrus aurantifolia) in India

Plant Disease ◽  
2017 ◽  
Vol 101 (5) ◽  
pp. 831-831 ◽  
Author(s):  
D. K. Ghosh ◽  
S. Bhose ◽  
P. Sharma ◽  
A. Warghane ◽  
M. Motghare ◽  
...  
Author(s):  
Syed Ali Razvi ◽  
Rashid Al-Shidi ◽  
Najma Mahmood Al-Zadjali ◽  
Yousuf Mohammad Al-Raeesy

Regular monitoring of hemipteran hopper species (including psyllids) associated with small-fruited acid lime trees (Citrus aurantifolia L.) was conducted for four years using motorized insect suction to determine the possible vectors of witches’- broom disease of lime (WBDL). The study was done in two phases: monitoring was done in Habra village, Wilayat Wadi AlMaawal (Batinah region) for one year from June 2000 to May 2001; then monitoring was done in Maharah village, Wilayat AlMusannah (Batinah region), for a period of three years from May 2001 to April 2004. Twelve species of cicadellid leafhoppers and one delpahacid planthopper species were collected, while no psyllids were found. Hishimonus phycitis (Distant) (Cicadellidae) was the most abundant hopper (78.4 % of collected individuals). Next in abundance were Toya sp. (Delphacidae), Circulifera haematiceps? and a deltocephalin leafhopper, respectively constituting 10.4, 3.8 and 2.4 % of the total catches of the four years. Nine other species made up 5% of the total collection: Exitianus nanus (Distant), Cicadulina sp. (either chinai (Ghauri) or storeyi (China)), Emposca distinguenda (Paoli), Amrasca biguttula (Ishihara), Deltocephalus (Recilia) pruthii (Metcalf), Neolimnus aegyptiacus (Mutsumura) and three undetermined species (one Deltocephalinae, one Typhlocybinae and one undeterminable to subfamily). Catches of H. phycitis were highest from November to March and lowest from May to September. There was a significant linear relationship between number of H. phycitis and maximum and mininmum temperature. Relative humidity was not significantly correlated to number of H. phycitis. In Maharah, young lime trees were free from WBDL but the disease incidence increased with age. H. phycitis is the best candidate vector of WBDL. The potential of Toya sp., Circulifera haematiceps? and an undetermined deltocephalin as candidate vectors is discussed. Finally, it is suggested that regular sprayings of acid lime trees with effective systemic insecticides during November to March each year can greatly reduce the vector population and can prevent or delay the spread of the disease to a great extent.


Plant Disease ◽  
2014 ◽  
Vol 98 (11) ◽  
pp. 1577-1577 ◽  
Author(s):  
F. N. Silva ◽  
R. B. Queiroz ◽  
A. N. Souza ◽  
A. M. Al-Sadi ◽  
D. L. Siqueira ◽  
...  

At present, the principal bacterial disease of citrus in Brazil is Huanglongbing, caused by the alpha-proteobacterium ‘Candidatus Liberibacter spp.’ (although a phytoplasma of the 16SrIX group is also associated with this disease [4]). While there is a wide diversity of phytoplasmas in crop species in Brazil (3), there have been no reports of symptoms associated with phytoplasma in Brazilian citrus. Asymptomatic infections of citrus cannot be excluded as a possibility and such plants could serve as a reservoir of phytoplasma inoculum. The aim of this study was to assess the presence of phytoplasma in asymptomatic Citrus aurantifolia (acid lime) in Brazil. Thirty-three leaf samples (young leaves from the upper canopies) were randomly collected from different plants in the states of Minas Gerais (n = 23), Santa Catarina (n = 2), and São Paulo (n = 8). Two additional samples of C. limonia (‘Rangpur’ lime) and one of C. latifolia (‘Persian’ or ‘Tahiti’ lime) were collected in Minas Gerais. Total DNA extraction was performed using NucleoSpin Plant II Kit (Macherey-Nagel) according to the manufacturer's recommendations. PCR was carried out with a universal P1/P7 primer set followed by nested primers R16F2n/R16R2 (2). Additionally, direct PCR was performed using primers specific for phytoplasma immune-dominant membrane protein IMP3F/IMP3R (1). ‘Rangpur’ and ‘Tahiti’ lime were not infected with phytoplasma. Of the C. aurantifolia samples, 52% were positive for phytoplasma in the direct and nested PCR assays. The numbers of positive samples in Minas Gerais, Santa Catarina, and São Paulo states were 12, 1, and 4, respectively. Of these, five were selected for DNA purification and 1,246-bp fragments were ligated to the pGEM T-easy vector (Promega) and partial 16Sr DNA was sequenced. Nucleotide sequences of Brazilian phytoplasma strains BR:MG:FNS10:2011, BR:MG:FNS53:2011, BR:SP:FNS73:2011, BR:SC:FNS86:2011, and BR:MG:FNS126:2012 (GenBank Accession Nos. KJ158173, KJ158174, KJ158175, KJ158176, and KJ158177, respectively) were subjected to RFLP analyses. The 16S rDNA RFLP in silico patterns for the five strains were identical to each other and to Cactus witches'-broom phytoplasma (16SrII-C subgroup, AJ293216). In addition, the highest similarity coefficient (5) and nucleotide sequence identity of Brazilian phytoplasma strains were 0.99 and 99%, respectively, with Cactus witches'-broom phytoplasma. PCR-RFLP analyses using the enzymes Bstu I, EcoR I, and Hpa II were consistent with RFLP in silico results, showing the same pattern as the 16SrII-C subgroup. Phylogenetic analyses based on 16S rDNA sequences (1,246 bp) demonstrated that all the Brazilian strains grouped in the same clade with other representative sequences from the 16S rDNAII group. To confirm the absence of any macroscopic symptoms, morphological characteristics of 10 uninfected and 10 phytoplasma-infected plants randomly selected from a single field in Minas Gerais were analyzed. There were no significant differences in leaf area, stalk diameter, or numbers of leaves, flowers, or fruits per branch. To our knowledge, this is the first report of the 16SrII-C subgroup phytoplasma associated with C. aurantifolia in Brazil, and the first report of asymptomatic citrus plants infected with phytoplasma. References: (1) N. Askari et al. J. Microbiol. Biotechnol. 21:81, 2011. (2) I. M. Lee et al. Phytopathology 84:559, 1994. (3) H. G. Montano et al. Bull. Insectol. 60:129, 2007. (4) D. C. Teixeira et al. Phytopathology 98:977, 2008. (5) Y. Zhao et al. Meth. Mol. Biol. 938:329, 2013.


Plant Disease ◽  
1999 ◽  
Vol 83 (3) ◽  
pp. 302-302 ◽  
Author(s):  
D. K. Ghosh ◽  
A. K. Das ◽  
Shyam Singh ◽  
S. J. Singh ◽  
Y. S. Ahlawat

In India, acid lime (Citrus aurantifolia (L.) Swingle) is one of the most important citrus fruits grown. It constitutes nearly 20% of the total citrus production. During 1995, an unusual type of disease was observed on a 6-year-old acid lime plant in an orchard in the Nagpur District in eastern Maharashtra. It was named witches'-broom disease (WBD) to reflect the most conspicuous symptom. Other symptoms included small chlorotic leaves, highly proliferated shoots, and shortened internodes. Leaves dropped prematurely and infected twigs were distorted. In advanced stages, infected branches had dieback symptoms. WBD of lime has been reported from Oman and UAE (1) and the causal phytoplasma was designated “Candidatus Phytoplasma aurantifolia” (2). Subsequent surveys in 1995-1998 revealed disease incidences as high as 5% in Maharashtra and in other major acid-lime-growing states—Andhra Pradesh, Tamilnadu, and Karnataka. After the grafting of infected acid lime shoots, disease symptoms developed on Troyer citrange, rough lemon, and Rangpur lime, but not on sweet orange (mosambi), mandarin (Nagpur), or trifoliate orange. The WBD agent was transmitted from infected acid lime to periwinkle (Catharanthus roseus) plants and vice versa by dodder (Cuscuta reflexa). Ultrathin sections of leaf midrib of infected acid lime plants were fixed on copper grids, stained with uranyl acetate and lead acetate, and examined in a JEM 100S transmission electron microscope. Numerous bodies having the characteristic morphology of phytoplasmas were observed in phloem sieve tubes of acid lime in diseased but not in healthy leaves. The phytoplasmal bodies ranged from 100 to 800 nm in diameter and were bounded by a poorly defined membrance. Freehand transverse sections of young internode regions of a WBD-infected periwinkle plant were stained in DAPI (4′, 6 diamidino-2-phenylindole; 1.0 μg/ml) and were observed with a fluorescent microscope (Leica). An intense bluish-white fluorescence in the phloem elements of diseased periwinkle and its absence in healthy samples were consistent with the presence of phytoplasmas. This is the first report of phytoplasma-induced witches'-broom disease of acid lime in India. References: (1) M. Garnier et al. Plant Dis. 75:546, 1991. (2) L. Zreik et al. Int. J. Syst. Bacteriol. 45:449,1995.


2017 ◽  
Vol 66 (8) ◽  
pp. 1380-1388 ◽  
Author(s):  
A. G. Al-Ghaithi ◽  
A. M. Al-Sadi ◽  
M. S. Al-Hammadi ◽  
R. M. Al-Shariqi ◽  
R. A. Al-Yahyai ◽  
...  

Plant Disease ◽  
2011 ◽  
Vol 95 (3) ◽  
pp. 360-360 ◽  
Author(s):  
A. M. Al-Subhi ◽  
N. A. Al-Saady ◽  
A. J. Khan ◽  
M. L. Deadman

Eggplant (Solanum melongena L.) belongs to the family Solanaceae and is an important vegetable cash crop grown in most parts of Oman. In February 2010, plants showing phyllody symptoms and proliferation of shoots resembling those caused by phytoplasma infection were observed at Khasab, 500 km north of Muscat. Total genomic DNA was extracted from healthy and two symptomatic plants with a modified (CTAB) buffer method (2) and analyzed by direct and nested PCR with universal phytoplasma 16S rDNA primers P1/P7 and R16F2n/ R16R2, respectively. PCR amplifications from all infected plants yielded an expected product of 1.8 kb with P1/P7 primers and a 1.2-kb fragment with nested PCR, while no products were evident with DNA from healthy plants. Restriction fragment length polymorphism (RFLP) profiles of the 1.2-kb nested PCR products of two eggplant phyllody phytoplasma and five phytoplasma control strains belonging to different groups used as positive control were generated with the restriction endonucleases RsaI, AluI, Tru9I, T-HB8I, and HpaII. The eggplant phytoplasma DNA yielded patterns similar to alfalfa witches'-broom phytoplasma (GenBank Accession No. AF438413) belonging to subgroup 16SrII-D, which has been recorded in Oman (1). The DNA sequence of the 1.8-kb direct PCR product was deposited in GenBank (Accession No. HQ423156). Sequence homology results using BLAST revealed that the eggplant phyllody phytoplasma shared >99% sequence identity with Scaevola witches'-broom phytoplasma (Accession No. AB257291.1), eggplant phyllody phytoplasma (Accession No. FN257482.1), and alfalfa witches'-broom phytoplasma (Accession No. AY169323). The RFLP and BLAST results of 16S rRNA gene sequences confirm that eggplant phyllody phytoplasma is similar to the alfalfa phytoplasma belonging to subgroup 16SrII-D. To our knowledge, this is the first report of a phytoplasma of the 16SrII-D group causing witches'-broom disease on eggplant in Oman. References: (1) A. J. Khan et al. Phytopathology 92:1038, 2002. (2) M. A. Saghai-Maroof et al. Proc. Natl. Acad. Sci. USA, 81:8014, 1984.


2020 ◽  
Vol 261 ◽  
pp. 108935
Author(s):  
M.S. Ladaniya ◽  
R.A. Marathe ◽  
A.K. Das ◽  
C.N. Rao ◽  
A.D. Huchche ◽  
...  

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