A Phytoplasma Related to 'Candidatus Phytoplasma asteri' Detected in Citrus Showing Huanglongbing (Yellow Shoot Disease) Symptoms in Guangdong, P. R. China

被引：51

作者：

Chen, J. ^{[1
,3
]}

Pu, X.

Deng, X. ^{[3
]}

Liu, S. ^{[2
]}

Li, H. ^{[3
]}

Civerolo, E.

机构：

[1] ARS, San Joaquin Valley Agr Sci Ctr, USDA, Parlier, CA 93648 USA

[2] S China Agr Univ, Dept Soil Sci, Guangzhou, Guangdong, Peoples R China

[3] S China Agr Univ, Dept Plant Pathol, Citrus Huanglongbing Res Lab, Guangzhou, Guangdong, Peoples R China

来源：

PHYTOPATHOLOGY | 2009年 / 99卷 / 03期

关键词：

GREENING DISEASE; WITCHES-BROOM; SAO-PAULO; PCR; IDENTIFICATION; AMPLIFICATION; BACTERIUM; SEQUENCES; STATE;

D O I：

10.1094/PHYTO-99-3-0236

中图分类号：

Q94 [植物学];

学科分类号：

071001 ;

摘要：

Citrus huanglongbing (HLB) or yellow shoot disease (i.e., greening disease) is highly destructive to citrus production worldwide. Understanding the etiology of HLB is critical for managing the disease. HLB is currently associated with infection by 'Candidatus Liberibacter spp.' around the world, including China. However, Koch's postulates have not been fulfilled. In addition, other plant pathogens also may be involved in HLB. In a survey performed in Guangdong Province, P. R. China in 2006 and 2007, 141 citrus samples showing typical symptoms of HLB from 11 different cities were collected. Polymerase chain reaction (PCR) using phytoplasma-specific primer sets fU5/rU3 nested with primer set P1/P7 identified 110 (78.0%) positive samples. A 1,785-bp amplicon was obtained with primer set P1/P7. Analysis showed a 100% identity of this sequence in the region of 16S rDNA and 16S-23S rRNA intergenic transcribed spacer to three strains of 'Candidatus Phytoplasma asteri' (onion yellows [Japan], aster yellows 'watercress' [Hawaii], and valeriana yellows [Lithuania]). Of the 141 samples, 89 (63.1%) samples were positive for 'Ca. Liberibacter asiaticus'. When mixed infection was considered, 69 (48.9%) samples were positive for both 'Ca. P. asteri' and 'Ca. L. asiaticus'. Transmission electron microscopy (TEM) showed low titers of both walled and wall-less bodies in the phloem sieve tubes of HLB citrus. When transmission from symptomatic citrus to periwinkle (Catharanthus roseus) via dodder (Cuscuta campestris) was conducted, both phytoplasma and 'Ca. L. asiaticus' were detected from the affected periwinkle. In addition to yellowing/mottling, the infected periwinkle showed symptoms of virescence and phyllody which are commonly associated with phytoplasmal diseases. TEM analysis of affected periwinkle revealed pleomorphic and wall-less organisms, characteristic of phytoplasmas, filling some phloem sieve tubes. In contrast, walled bacteria were at low titer. This study showed that in addition to 'Ca. L. asiaticus', a phytoplasma related to 'Ca. P. asteri' could also be detected in citrus showing HLB symptoms in Guangdong.

引用

页码：236 / 242

页数：7

共 39 条

[1] First report of a 16SrII group phytoplasma associated with die-back diseases of papaya and citrus in Ethiopia [J].

Arocha, Y. ;

Bekele, B. ;

Tadesse, D. ;

Jones, P. .

PLANT PATHOLOGY, 2007, 56 (06) :1039-1039

[2]

Bove J., 1986, FAO Plant Protection Bulletin, V34, P217

[3]

Bove J. M., 2000, Proceedings of the 14th Conference of the International Organization of Citrus Virologists, Campinas, Sao Paulo State, Brazil, 13-18 September 1998, P207

[4]

Bové JM, 2006, J PLANT PATHOL, V88, P7

[5]

Chen Chen, 1943, New. Agric. J. Yungan, Fukien., V3, P142

[6]

CHEN TY, 1979, ACTA BIOCH BIOPH SIN, V11, P191

[7] Analysis of 16S rDNA sequences from citrus huanglongbing bacteria reveal a different "Ca. Liberibacter" strain associated with citrus disease in Sao Paulo [J].