<b>Elimination of phytoplasma by stem culture from mulberry plants (<i>Morus alba</i>) with dwarf disease</b>

Dai, Qun; He, Feng; Liu, P.-Y.

doi:10.1046/j.1365-3059.1997.d01-202.x

Cited by 17 publications

(13 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…There are several possible explanations. It is anticipated that the levels of phytohormones may play a role because they also influence the development of phytoplasma‐induced symptoms (Chen et al ., 1991; Dai et al ., 1997). The cytokinin/auxin ratio may be important (Chen et al ., 1991; Dai et al ., 1997).…”

Section: Discussionmentioning

confidence: 99%

“…Phytoplasmas are restricted to the phloem (Waters & Hunt, 1980) and colonise meristems poorly (Lee et al ., 2000). Pathogen‐tested plant stocks, in which phytoplasmas have not been detected, have been obtained using many different techniques, such as shoot tip culture (Green et al ., 1989; Wongkaew & Fletcher, 2004; Chalak et al ., 2005), thermotherapy (Kahn et al ., 1972; Green et al ., 1989; Chalak et al ., 2005), leaf tissue‐derived somatic embryogenesis (Parmessur et al ., 2002), organogenesis (Wongkaew & Fletcher, 2004), stem culture (Dai et al ., 1997), micrografting (Chalak et al ., 2005) and treatment of plant tissues with antibiotics (Green et al ., 1989; Davies & Clark, 1994; Wongkaew & Fletcher, 2004). Recently, cryotherapy has appeared as a new approach for producing virus‐free plants (Brison et al ., 1997; Helliot et al ., 2002; Wang et al ., 2003, 2006) but it has not been tested for elimination of phytoplasma and other pathogens.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Efficient elimination of sweetpotato little leaf phytoplasma from sweetpotato by cryotherapy of shoot tips

Wang

Valkonen

2008

Plant Pathology

View full text Add to dashboard Cite

Shoot tips with 3-4 leaf primordia were excised from in vitro -grown sweetpotato plants ( Ipomoea batatas ) infected with little leaf phytoplasma ( Candidatus Phytoplasma aurantifolia) and subjected to cryotherapy. All plants regenerated from the cryo-treated shoot tips were free of phytoplasma, whereas shoot tip culture or dehydration of shoot tips without subsequent cryotherapy resulted in phytoplasma-free plants at a frequency of only 7-10%. Histological and ultrastructural studies with light and transmission electron microscopy, respectively, indicated that cryotherapy was lethal to all cells except those in the apical dome of the meristem and the two youngest leaf primordia. These surviving parts of the shoot tip contained vascular tissue and sieve elements, but electron microscopy showed no phytoplasma in them. In contrast, an abundance of phytoplasma was found in sieve elements located at the lower, non-surviving parts of the shoot tip 1·0 or 1·5 mm from the apical dome. In the greenhouse, the plants in which phytoplasmas were not detected were healthy-looking, grew vigorously and were readily distinguished from the infected plants that exhibited little leaf and chlorosis symptoms, proliferation of axillary shoots and roots, stunting, and heavily reduced number and size of storage roots. In this study efficient elimination of phytoplasma and production of pathogen-tested plant stocks were achieved with the novel cryotherapy-based approach. The proposed advantage of the technique is that it can be simultaneously used for long-term storage of plant germplasm and for production of pathogen-free plants.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Efficient elimination of sweetpotato little leaf phytoplasma from sweetpotato by cryotherapy of shoot tips

Wang

Valkonen

2008

Plant Pathology

View full text Add to dashboard Cite

show abstract

“…The regenerated mulberry plants were found to be apparently free from infection to an extent of 70-90%. The results of DAPI fluorescence test were comparable to that of PCR assay (Dai et al 1997). In another study, a total of 200 samples of Arizona or velvet ash (Fraxinus velutina) cv.…”

Section: Histochemical Methodsmentioning

confidence: 53%

Detection of Bacterial and Phytoplasmal Pathogens

Narayanasamy¹

2010

Microbial Plant Pathogens-Detection and Disease Diagnosis:

View full text Add to dashboard Cite

Bacterial pathogens classified as prokaryotes are much simpler in structure and smaller in size and they have less complex structural features compared to fungal plant pathogens. As the morphological characteristics of bacterial cells are less variable, biological, biochemical, physiological, immunological and genomic characteristics have to be determined for reliable identification and meaningful classification of bacterial pathogens. Detection and identification of bacterial plant pathogens present in whole plants and in propagative plant materials have been possible by employing isolation on cultural media and metabolic fingerprinting methods. But they are labor-intensive and require long time. Results often are inconclusive. Isozyme analysis, direct colony thin layer chromatography and gel electrophoresis techniques have been successfully applied for the detection of some bacterial pathogens. Immunoassays and nucleic acid-based assays have become widely accepted techniques, providing more sensitive and specific detection and quantification of bacterial pathogens affecting a wide range of host plant species. However, the major limitation of the molecular techniques is their inability to discriminate living cells from the dead ones. Attempts have been made to overcome this limiting factor by using DNA binding dyes and estimating pathogen RNAs as an indicator of cell viability. The diagnostic methods have both merits and demerits and hence, appropriate method has to be selected based on cost-effectiveness and possibility of obtaining reliable results rapidly to suit the requirements of the investigation concerned.Phytoplasmas are cell wall-less, nonculturable bacteria belonging to Mollicutes. Lack of cultural characteristics has made obligatory to study the morphological characteristics of phytoplasmas present in the phloem cells of infected plant hosts by observing under electron microscopes. As most of the phytoplasmas look alike in the ultrathin sections, the morphological characters have no diagnostic value. Histochemical methods using DNA binding dyes have been employed to localize the phytoplasmas in the host cells. Application of immunoassays and nucleic acidbased techniques has been effective in providing information for the identification and differentiation of phytoplasams. Polyclonal and monoclonal antibodies have been generated for detection of phytoplasmas infecting several plant species. Universal and species-specific primers and probes have been designed based on

show abstract

“…It is thought that the symptoms of phytoplasma disease are mainly caused by the rise of the cytokinin/auxin ratio in infected plants. Dai et al (1997) have stated that the elimination of phytoplasma from the infected Morus alba culture may be related to the decrease of the cytokinin/auxin ratio. Cytokinin plays an important role in the distribution of nutrient materials (Bidwell 1979).…”

Section: Phytoplasma Detection In Tissue Culture Of Rose Stored Undermentioning

confidence: 99%

“…Cytokinin plays an important role in the distribution of nutrient materials (Bidwell 1979). The decrease of cytokinins can limit the nutrients required by the phytoplasmas and inhibit their reproduction; the resumption of normal growth of the stem segments can raise their resistance to the phytoplasma (Dai et al 1997).…”

Section: Phytoplasma Detection In Tissue Culture Of Rose Stored Undermentioning

confidence: 99%

Phytoplasma detection in rose shoots propagated in vitro

2011

View full text Add to dashboard Cite

The results of PCR examination indicated that during two years of tissue culture at standard conditions, on the medium with BAP 1 mg l -1 and continuous temperature of 20°C, phytoplasma could be detected in diseased plants of rose cv Sacha and Jazz. In the second year of micropropagation phytoplasma detection rate in tissues of infected roses increased and was relatively higher than in the first one. To test whether phytoplasmas are sensitive to temperature and light intensity, phytoplasma-affected micropropagated rose plants were grown on medium with BAP 1.0 or 0.5 mg l -1 and at the temperature of 4, 15, 20 or 25°C in darkness or in the light. PCR analysis indicated that phytoplasma detection was not effected by these conditions during 4 weeks of culturing. However, phytoplasma was not detectable in rose plants after 8 weeks culturing on the same medium without transplanting. Micropropagated rose shoots maintained on medium with Gentamycin or Baytril at the concentration of 25.0 or 50.0 mg l -1 had reduced growth and were chlorotic. However, no direct effect of applied antibiotics on phytoplasma detection was evidenced.

show abstract

**Elimination of phytoplasma by stem culture from mulberry plants (Morus alba) with dwarf disease**

Cited by 17 publications

References 11 publications

Efficient elimination of sweetpotato little leaf phytoplasma from sweetpotato by cryotherapy of shoot tips

Efficient elimination of sweetpotato little leaf phytoplasma from sweetpotato by cryotherapy of shoot tips

Detection of Bacterial and Phytoplasmal Pathogens

Phytoplasma detection in rose shoots propagated in vitro

Contact Info

Product

Resources

About