• Research in Plant Disease
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• v.30 no.1
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• pp.78-81
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• 2024

This study aims to isolate and identify the fungal pathogen responsible for gummosis disease affecting Thanh Tra pomelo in Vietnam. Through molecular identification utilizing primer pairs ITS5 and ITS4, the analysis pinpointed Lasiodiplodia theobromae as the specific fungal pathogen. Notably, the fungal colonies exhibited vigorous growth on potato dextrose agar. Initially, these colonies appeared whitish-grey, transforming into a black-grey hue within 5-7 days at a temperature of 30℃. According to previous reports, Phytophthora spp. was the most common pathogenic genus causing gummosis on Thanh Tra pomelo in Vietnam. To our knowledge, this is the first report on L. theobromae causing gummosis on Thanh Tra pomelo in Vietnam.

• Research in Plant Disease
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• v.23 no.4
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• pp.367-371
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• 2017

In 2015, symptoms of die-back on Rosa hybrida were observed in Taean, Korea. The aims of this study were to determine the cause of die-back on Rosa hybrida and characterize the pathogen. The fungal isolates were obtained and used for pathogenicity test, morphological and molecular analyses. The pathogenicity test on healthy branches of Rosa hybrida produced die-back, as the original symptoms. For the morphological study, the isolates were inoculated onto potato dextrose agar and incubated for 7 days at $25^{\circ}C$. The colonies grew up quickly and turned white to gray in color. Conidia were observed under an optical microscope. The features of conidia were ellipsoidal, grayish brown in color, $20-31{\times}11-17{\mu}m$ in size and had one septum. Molecular analyses of the ITS region, TEF and TUB genes were conducted to confirm the identity of the pathogen. The phylogenetic tree of the multi-gene sequences indicated that the causal agent was Lasiodiplodia pseudotheobromae. This study is the first report of die-back caused by Lasiodiplodia pseudotheobromae on Rose (Rosa hybrida).

• Mycobiology
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• v.37 no.4
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• pp.308-309
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• 2009

Powdery mildews on over 40 plants in Bangalore were screened during July-December of 2003~2008. Isolates from mycoparasitised Oidium caesalpiniacearum of Bauhinia purpurea comprised Lasiodiplodia theobromae, in addition to Ampelomyces quisqualis. Koch's postulates were satisfied to establish the mycoparasitism of L. theobromae. This is the first report that L. theobromae acts as a mycoparasite of a powdery mildew.

• Mycobiology
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• v.44 no.4
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• pp.319-324
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• 2016

Dieback in strawberry (Seolhyang cultivar) was first observed during the nursery season (June to September) in the Nonsan area of Korea in the years 2012 and 2013. Initial disease symptoms included dieback on runners, as well as black rot on roots, followed by wilting and eventually blackened, necrotic discoloration in the crowns of daughter plants. A fungus isolated from the diseased roots, runners, and crowns is close to Lasiodiplodia theobromae based on morphological characteristics. Analysis of a combined dataset assembled from sequences of the internal transcribed spacer and translation elongation factor 1- alpha genes grouped nine fungal isolates with the type strain of L. theobromae. The isolates showed strong pathogenicity on strawberry cultivars Kumhyang, Seolhyang, and Akihimae, fulfilling Koch's postulates. Based on these results, the pathogen responsible for dieback on strawberry plants in Korea was identified as L. theobromae.

• Korean Journal of Agricultural Science
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• v.25 no.1
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• pp.118-123
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• 1998

Lasiodiplodia theobrorme is a pathogen of Java black rot on sweet potato. This fungus infects the tuberous root during storage after harvest. Invasion of the fungus results in the expansion of necrosis sites into the tuberous roots. The resultant necrotic symptom of the tissue is also induced by application of acetone extract of the fungus growing on potato sucrose agar (PSA) culture. The active principles to induce the necrosis are purified from the acetone extract as follows. After evaporation of hexane-benzene-EtOAc (1:2:1, v/v/v) the extract was fractioned on silica gel column, using a solvent gradient system from n-hexane to EtOAc and then to MeOH. The active fractions were purified with HPLC on Nucleosil 50-5 column by eluting n-hexane to EtOAc. Their structures are established by using spectroscopic techniques and synthesis to 4-hydroxymellein and mellein, respectively. Application of small amount of these compounds induce expansion of the necrotic symptom into the tissue and accumulated ipomeamarone. Conclusively, these compounds acted as phytotoxins (inducing necrosis) and as elicitors (eliciting the phytoalexin).

• The Plant Pathology Journal
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• v.38 no.4
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• pp.272-286
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• 2022

Black root rot (BRR) caused by Lasiodiplodia theobromae is an alarming disease of mulberry that causes tremendous economic losses to sericulture farmers in India and China. Successful control of this disease can be attained by screening germplasm and identifying resistant sources. Seventy four diseased root samples were collected from farmer's fields belonging to four major mulberry growing states of South India. Based on morpho-cultural and scanning electron microscopy studies, 57 fungal isolates were characterized and identified as L. theobromae. Phylogenetic analysis of concatenated internal transcribed spacer and β-tubulin sequences revealed variation of the representative 20 isolates of L. theobromae. Following the root dip method of inoculation, pathogenicity studies on susceptible mulberry genotypes (Victory-1 and Thailand male) recognized the virulent isolate MRR-142. Accordingly, MRR-142 isolate was used to evaluate resistance on a set of 45 diverse mulberry accessions. In the repeated experiments, the mulberry accession ME-0168 which is an Indonesian origin belonging to Morus latifolia was found to be highly resistant consistently against BRR. Eight accessions (G2, ME-0006, ME-0011, ME-0093, MI-0006, MI-0291, MI-0489, and MI-0501) were found to be resistant. These promising resistant resources may be exploited in mulberry breeding for developing BRR resistant varieties and to develop mapping populations which successively helps in the identification of molecular markers associated with BRR.

• Plant Resources
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• v.4 no.2
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• pp.65-74
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• 2001

Coleus forskohlii Briq, of the family Lamiaceae yields a valuable secondary metabolity known as forskolin which is a labdane diterpenoid.. Coleus forskohlii is the only known source of this compound. Forskolin is used in medicine for the treatment of glaucoma, congestive cardiomyopathy and asthma. Morphogenic callus was induced from young leaves on MS medium augmented with NAA and BA. These calli, when subcultured on MS with KN alone gave rise to shoots. The regenerated shoot developed good root system on MS medium fortified with NAA. The fully grown plantlets were transferred to soil for acclimatization. Coleus plant is mainly infected by a fungi Lasiodiplodia theobromae which causes root rot disease. The fungal culture filterate (ECE) of Lasiodiplodia theobromae, has been used in regeneration media to find the MIC and further to select resistant plants to the pathogen. In the present study 40% ECF in the medium showed maximum inhibition and is there fore considered as the MIC level of Coleus forshohlii. This data could prove to be useful for the future for selecting a resistant C.forskohlii plant against the root disease caused by L. theobromae.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2000.10a
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• pp.96-113
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• 2000

Coleus forskohlii Briq. of the family Lamiaceae yields a valuable secondary metabolite known as forskolin which is a labdane diterpenoid. Coleus forskohlii is the only known source of this compound. Forskolin is used in medicine for the treatment of glaucoma, congestive cardiomyopathy and asthma. Morphogenic callus was induced from young leaves on MS medium augmented with NAA and BA. These calli, when subcultured on MS with KN alone gave rise to shoots. The regenerated shoot developed good root system on MS medium fortified with NAA. The fully grown plantlets were transferred to soil for acclimatization. Coleus plant is mainly infected by a fungi Lasiodiplodia theobromae which causes root of disease. The fungal culture filterate (FCF) of Lasiodiplodia theobromae, has been used in regeneration media to find the MIC and further to select resistant plants to the pathogen. In the present study 40% FCF in the medium showed maximum inhibition and is there fore considered as the MIC level of Coleus forskohlii. This data could prove to be useful for the future for selecting a resistant C,forskohlii plant against the root disease caused by L.theobromae.

• The Plant Pathology Journal
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• v.28 no.4
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• pp.455-455
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• 2012

• Journal of Microbiology and Biotechnology
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• v.20 no.2
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• pp.319-324
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• 2010

Phorbol ester extraction was carried out from Jatropha curcas seed cake, a by-product from the biodiesel fuel industry. Four repeated extractions from 5 g of J. curcas seed cake using 15 ml of 90% (v/v) ethanol and a shaking speed of 150 rpm gave the highest yield of phorbol esters. The ethanolic extract of J. curcas seed cake showed antifungal activities against important fungal phytopathogens: Fusarium oxysporum, Pythium aphanidermatum, Lasiodiplodia theobromae, Curvularia lunata, Fusarium semitectum, Colletotrichum capsid, and Colletotrichum gloeosporioides. The extract contained phorbol esters mainly responsible for antifungal activities. The extract could therefore be used as an antifungal agent for agricultural applications.