scholarly journals Phenotypic and Molecular Characterization of Strains Lasiododulpodia theobromae (pat) Griffon & Maulk, Pathogen-Associated with Black Rot Cocoa Pods in the Tshopo Province, Kisangani Region (DR Congo)

2021 ◽  
pp. 42-50
Author(s):  
K. Limba ◽  
K. Kwembe ◽  
K. Asumani ◽  
T. K. Monde ◽  
G. Hassaert ◽  
...  
Keyword(s):  
Democratic Republic Of Congo ◽  
Pcr Amplification ◽  
Soft Rot ◽  
Fungal Species ◽  
Internal Transcribed Spacers ◽  
Black Rot ◽  
Perennial Crop ◽  
Tropical Regions ◽  
Rot Disease ◽  
Production Period

The cocoa tree (Theobroma cacao L) is a persistent perennial crop in tropical regions whose production period is sufficiently spread out over the whole year.  As a result, it offers pathogens conditions for survival without real disruption of their life cycle.  Symptoms of cocoa pod black rot disease have been observed in both the Bengamisa cocoa growing area and the Yangambi area in the Democratic Republic of Congo (DRC). This study aimed to characterize the strains of Lasiodiplodia theobromae on cocoa trees in the Kisangani region.  Macroscopic and microscopic observations were made on the pods while the identification of the species was confirmed by a molecular approach based on the sequencing of part of the ribosomal DNA including the ITS regions (internal transcribed spacers) and the 5.8S gene.  The results of this study showed that the phenotypic characteristics of the strains isolated in the two cocoa growing areas were typical of the L. Theobromae species. These are in particular the spots of soft rot, initially brown, gradually evolving into soot-black which subsequently produced a sort of whitish powder on the surface of the diseased pod.  However, the fruiting of the fungus in the PDA medium gave rise to the latter's mycelia, initially whitish, which darkened as they matured.  In addition, PCR amplification followed by sequencing of the fungal strain was beneficial by removing any doubt about the nature of the fungal species isolated in the two cocoa-growing areas.

scholarly journals Heart Rot of Pomegranate: Disease Etiology and the Events Leading to Development of Symptoms

Plant Disease ◽  
2015 ◽  
Vol 99 (4) ◽  
pp. 496-501 ◽  
Author(s):  
David Ezra ◽  
Benny Kirshner ◽  
Michal Hershcovich ◽  
Dani Shtienberg ◽  
Itzhak Kosto
Keyword(s):  
Fruit Development ◽  
Management Strategies ◽  
Soft Rot ◽  
Fruit Rot ◽  
Black Rot ◽  
Causative Pathogen ◽  
Disease Etiology ◽  
Rot Disease ◽  
Pomegranate Fruit ◽  
Organ Colonization

Pomegranate fruit rot disease, known as “heart rot” or “black heart,” is a major pomegranate disease that impacts production worldwide. Heart rot is characterized by black rot of the fruit core that spreads from the calyx area, whereas the outer peel and the hard rind retain their healthy appearance. Aims of the present study were to identify the pathogen that causes pomegranate heart rot in Israel and to study the dynamics of fruit-organ colonization by fungi during fruit development, as the first steps toward the development of management strategies. Several fungi were isolated from pomegranate fruits, among which were species of Penicillium, Aspergillus, Botrytis, and Rhizopus, but the causative pathogen of the disease was identified as Alternaria alternata. This fungus was isolated from the pistils of more than 85% of open flowers and ∼20% of the loculi of asymptomatic fruits and from all tissues of the symptomatic fruits. The dynamics of fruit-organ colonization by fungi during fruit development was recorded in six commercial orchards in 2010 and 2011. It was found that A. alternata spores germinate on the stigmata of open flowers and develop into the style. In some fruits, the mycelium grows into the tunnel and reaches the lower loculus, where the fungus becomes latent for about 3 to 4 months pending initiation of fruit ripening. Then, in a small number of fruits, the fungus starts growing and invades the arils, causing black rot of the arils in the lower loculus. At the beginning of disease development, the fungus causes brown soft rot of the arils, which becomes black and dry as the fungus grows. Eventually, the fungus grows from the lower loculus into the upper loculi, causing rot of the entire fruit.

Diseases of the kumara crop

2009 ◽  
Vol 62 ◽  
pp. 402-402
Author(s):  
S.L. Lewthwaite ◽  
P.J. Wright
Keyword(s):  
Fungal Pathogens ◽  
Ipomoea Batatas ◽  
Mechanical Damage ◽  
Soft Rot ◽  
Economic Loss ◽  
Root Surface ◽  
Black Rot ◽  
Rhizopus Stolonifer ◽  
Ceratocystis Fimbriata ◽  
Pink Rot

The predominant diseases of the commercial kumara (Ipomoea batatas) or sweetpotato crop are caused by fungal pathogens The field disease pink rot results from infection by the fungus Sclerotinia sclerotiorum Lesions form on vines but may spread down stems to the roots The widespread nature of this disease in sweetpotato appears peculiar to New Zealand Scurf is a disease caused by Monilochaetes infuscans which occurs in the field but may proliferate amongst stored roots The disease causes a superficial discolouration of the root surface which is mainly cosmetic but can also increase root water loss in storage Infection by Ceratocystis fimbriata produces a disease known as black rot The disease can be transmitted amongst plants at propagation but is particularly rampant amongst roots in storage This disease is readily transmitted and can cause severe economic loss Fusarium oxysporum causes surface rots in stored roots characterised by light to dark brown lesions that tend to be firm dry and superficial The lesions may be circular and centred on wounds caused by insects or mechanical damage at harvest Soft rot caused by Rhizopus stolonifer generally occurs in roots after they are washed and prepared for the market Fungal infection occurs through wounds or bruised tissue producing distinctive tufts of white fungal strands and black spores

Effect of Ozone onAspergillus nigerCausing Black Rot Disease in Onion

2006 ◽  
Vol 28 (5) ◽  
pp. 347-350 ◽  
Author(s):  
V. R. Vijayanandraj ◽  
D. Nagendra Prasad ◽  
N. Mohan ◽  
M. Gunasekaran
Keyword(s):  
Black Rot ◽  
Rot Disease

scholarly journals Morpho-molecular identification and first report of Fusarium equiseti in causing chilli wilt from Kashmir (Northern Himalayas)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ammarah Hami ◽  
Rovidha S. Rasool ◽  
Nisar A. Khan ◽  
Sheikh Mansoor ◽  
Mudasir A. Mir ◽  
...  
Keyword(s):  
Dna Barcoding ◽  
Pcr Amplification ◽  
Its Region ◽  
Fungal Species ◽  
Pathogenicity Test ◽  
Kashmir Valley ◽  
Fusarium Equiseti ◽  
Infected Root ◽  
Fusarium Sp ◽  
High Degree

AbstractChilli (Capsicum annuum L.) is one of the most significant vegetable and spice crop. Wilt caused by Fusarium Sp. has emerged as a serious problem in chilli production. Internal transcribed spacer (ITS) region is widely used as a DNA barcoding marker to characterize the diversity and composition of Fusarium communities. ITS regions are heavily used in both molecular methods and ecological studies of fungi, because of its high degree of interspecific variability, conserved primer sites and multiple copy nature in the genome. In the present study we focused on morphological and molecular characterization of pathogen causing chilli wilt. Chilli plants were collected from four districts of Kashmir valley of Himalayan region. Pathogens were isolated from infected root and stem of the plants. Isolated pathogens were subjected to DNA extraction and PCR amplification. The amplified product was sequenced and three different wilt causing fungal isolates were obtained which are reported in the current investigation. In addition to Fusarium oxysporum and Fusarium solani, a new fungal species was found in association with the chilli wilt in Kashmir valley viz., Fusarium equiseti that has never been reported before from this region. The studies were confirmed by pathogenicity test and re-confirmation by DNA barcoding.

scholarly journals Application of Bacillus pumilus isolates for management of black rot disease in strawberry

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Farid Abd-El-Kareem ◽  
Ibrahim E. Elshahawy ◽  
Mahfouz M. M. Abd-Elgawad
Keyword(s):  
Root Rot ◽  
Bacillus Pumilus ◽  
Field Conditions ◽  
Black Rot ◽  
Bacterial Isolates ◽  
Black Root Rot ◽  
Root Rot Disease ◽  
Growth Area ◽  
Rot Disease ◽  
The Impact

Abstract Background Black root rot of strawberry plants caused by Rhizoctonia solani, Fusarium solani, and Pythium sp. is a serious disease in Egypt. Biocontrol agents have frequently proved to possess paramount and safe tools against many diseases. The impact of soil treatments with 3 Bacillus pumilus isolates on black root rot disease of strawberry plants caused by R. solani, F., and Pythium sp. under laboratory and field conditions was examined herein on the commonly used ‘Festival’ strawberry cultivar. To increase the bacterial adhesion and distribution on the roots, each seedling was dipped in bacterial cell suspension at 1 × 108 colony-forming units/ml of each separate bacterial isolate for 30 min then mixed with 5% Arabic gum. Results The tested B. pumilus isolates significantly reduced the growth area of these 3 fungi. The two bacterial isolates Nos. 2 and 3 reduced the growth area by more than 85.2, 83.6, and 89.0% for R. solani, F. solani, and Pythium sp., respectively. Likewise, the 3 bacterial isolates significantly (P ≤ 0.05) inhibited the disease under field conditions. Isolates Nos. 2 and 3 suppressed the disease incidence by 64.4 and 68.9% and disease severity by 65.3 and 67.3%, respectively. The fungicide Actamyl had effect similar to that of the 2 isolates. B. pumilus isolates significantly enhanced growth parameters and yields of strawberry plants; isolates Nos. 2 and 3 raised the yield by 66.7 and 73.3%, respectively. Conclusions Bacillus pumilus isolates could effectively manage the black rot disease in strawberry herein. Due to the significant impact of the root rot disease on strawberry yield, B. pumilus should be further tested to manage the disease on strawberry on large scale in Egypt.

scholarly journals Isolation and characterization of two virulent Aeromonads associated with haemorrhagic septicaemia and tail-rot disease in farmed climbing perch Anabas testudineus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abhishek Mazumder ◽  
Hrishikesh Choudhury ◽  
Abhinit Dey ◽  
Dandadhar Sarma
Keyword(s):  
Natural Infection ◽  
Winter Season ◽  
Pcr Amplification ◽  
Body Parts ◽  
Anabas Testudineus ◽  
Climbing Perch ◽  
Isolation And Characterization ◽  
Biochemical Characterisation ◽  
Rot Disease

AbstractDiseased Anabas testudineus exhibiting signs of tail-rot and ulcerations on body were collected from a fish farm in Assam, India during the winter season (November 2018 to January 2019). Swabs from the infected body parts were streaked on sterilized nutrient agar. Two dominant bacterial colonies were obtained, which were then isolated and labelled as AM-31 and AM-05. Standard biochemical characterisation and 16S rRNA and rpoB gene sequencing identified AM-31 isolate as Aeromonas hydrophila and AM-05 as Aeromonas jandaei. Symptoms similar to that of natural infection were observed on re-infecting both bacteria to disease-free A. testudineus, which confirmed their virulence. LC50 was determined at 1.3 × 104 (A. hydrophila) and 2.5 × 104 (A. jandaei) CFU per fish in intraperitoneal injection. Further, PCR amplification of specific genes responsible for virulence (aerolysin and enterotoxin) confirmed pathogenicity of both bacteria. Histopathology of kidney and liver in the experimentally-infected fishes revealed haemorrhage, tubular degeneration and vacuolation. Antibiotic profiles were also assessed for both bacteria. To the best of our knowledge, the present work is a first report on the mortality of farmed climbing perch naturally-infected by A. hydrophila as well as A. jandaei, with no records of pathogenicity of the latter in this fish.

scholarly journals Botanicals to Control Soft Rot Bacteria of Potato

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
M. M. Rahman ◽  
A. A. Khan ◽  
M. E. Ali ◽  
I. H. Mian ◽  
A. M. Akanda ◽  
...  
Keyword(s):  
Plant Extracts ◽  
Curcuma Longa ◽  
Soft Rot ◽  
Storage Condition ◽  
Storage Conditions ◽  
Leaf Extracts ◽  
Corchorus Capsularis ◽  
Rot Disease ◽  
And Storage

Extracts from eleven different plant species such as jute (Corchorus capsularisL.), cheerota (Swertia chiraitaHam.), chatim (Alstonia scholarisL.), mander (Erythrina variegata), bael (Aegle marmelosL.), marigold (Tagetes erecta), onion (Allium cepa), garlic (Allium sativumL.), neem (Azadiracta indica), lime (Citrus aurantifolia), and turmeric (Curcuma longaL.) were tested for antibacterial activity against potato soft rot bacteria,E. carotovorasubsp.carotovora (Ecc)P-138, underin vitroand storage conditions. Previously,EccP-138 was identified as the most aggressive soft rot bacterium in Bangladeshi potatoes. Of the 11 different plant extracts, only extracts from dried jute leaves and cheerota significantly inhibited growth ofEccP-138in vitro. Finally, both plant extracts were tested to control the soft rot disease of potato tuber under storage conditions. In a 22-week storage condition, the treated potatoes were significantly more protected against the soft rot infection than those of untreated samples in terms of infection rate and weight loss. The jute leaf extracts showed more pronounced inhibitory effects onEcc-138 growth both inin vitroand storage experiments.

scholarly journals The Ribosomal Protein RplY Is Required for Pectobacterium carotovorum Virulence and Is Induced by Zantedeschia elliotiana Extract

2017 ◽  
Vol 107 (11) ◽  
pp. 1322-1330 ◽  
Author(s):  
Huan Jiang ◽  
Mengyi Jiang ◽  
Liuke Yang ◽  
Peiyan Yao ◽  
Lin Ma ◽  
...  
Keyword(s):  
Plant Extract ◽  
Plant Cell Wall ◽  
Insertion Site ◽  
Bacterial Pathogen ◽  
Soft Rot ◽  
Kanamycin Resistance ◽  
Pectobacterium Carotovorum ◽  
Promoter Trap ◽  
Carotovorum Subsp ◽  
Rot Disease

Pectobacterium carotovorum subsp. carotovorum strain PccS1, a bacterial pathogen causing soft rot disease of Zantedeschia elliotiana (colored calla), was investigated for virulence genes induced by the host plant. Using a promoter-trap transposon (mariner), we obtained 500 transposon mutants showing kanamycin resistance dependent on extract of Z. elliotiana. One of these mutants, PM86, exhibited attenuated virulence on both Z. elliotiana and Brassica rapa subsp. pekinensis. The growth of PM86 was also reduced in minimal medium (MM), and the reduction was restored by adding plant extract to the MM. The gene containing the insertion site was identified as rplY. The deletion mutant ΔrplY, exhibited reduced virulence, motility and plant cell wall-degrading enzyme production but not biofilm formation. Analysis of gene expression and reporter fusions revealed that the rplY gene in PccS1 is up-regulated at both the transcriptional and the translational levels in the presence of plant extract. Our results suggest that rplY is induced by Z. elliotiana extract and is crucial for virulence in P. carotovorum subsp. carotovorum.

scholarly journals Kemampuan Bakteri Endofit Akar dan Ubi Kentang untuk Menekan Penyakit Busuk Lunak (Erwinia carotovora pv. carotovora) pada Ubi

Agrikultura ◽  
2016 ◽  
Vol 27 (3) ◽  
Author(s):  
Noor Istifadah ◽  
Muhamad Salman Umar ◽  
Sudarjat Sudarjat ◽  
Luciana Djaya
Keyword(s):  
Biological Control ◽  
Potato Tuber ◽  
Endophytic Bacteria ◽  
Erwinia Carotovora ◽  
Soft Rot ◽  
Soft Rot Disease ◽  
Post Harvest ◽  
Rot Disease

ABSTRACTThe abilities of endophytic bacteria from potato roots and tubers to suppress soft rot disease (Erwinia carotovora pv. carotovora) in potato tuberSoft rot disease caused by Erwinia carotovora pv. carotovora is one of limiting factors in cultivation and post harvest of potato. The eco-friendly control measure that can be developed for controlling the diseases is biological control. Microbes that are potential as biological control agents include endophytic bacteria. This paper discussed the results of study examining the potential of endophytic bacteria isolated from roots and tubers of potato to inhibit the growth of E. carotovora pv. carotovora in vitro and suppress soft rot disease in potato tuber. The results showed that among 24 isolates examined, four isolates of endophytic bacteria (one isolate from potato tuber and three isolates from potato roots) inhibited the growth of E. carotovora pv. carotovora in vitro with inhibition zone 3.5-6.8 mm. In the in vivo test, the isolates inhibited the soft rot disease in potato tuber by 71.5-86.4%. The isolate that tended to show relatively better inhibition in vitro and in vivo was isolate from potato tuber which is CK U3 (Lysinibacillus sp.)Keywords: Biological control, Endophytic bacteria, Post-harvest, Potato, Soft rot diseaseABSTRAKPenyakit busuk lunak yang disebabkan bakteri Erwinia carotovora pv. carotovora, merupakan salah satu kendala dalam budidaya dan pascapanen kentang. Cara pengendalian ramah lingkungan yang dapat dikembangkan untuk menekan penyakit tersebut adalah pengendalian biologi. Kelompok mikroba yang berpotensi sebagi agens pengendali biologi adalah bakteri endofit. Artikel ini mendiskusikan potensi isolat bakteri endofit yang berasal dari ubi dan akar kentang untuk menghambat pertumbuhan bakteri E. carotovora pv. carotovora secara in vitro dan menekan perkembangan penyakit busuk lunak pada ubi kentang. Hasil percobaan menunjukkan bahwa diantara 24 isolat bakteri yang diuji, terdapat empat isolat bakteri endofit (satu isolat dari ubi kentang dan tiga isolat dari akar kentang) yang dapat menghambat pertumbuhan bakteri E. carotovora pv. carotovora secara in vitro dengan zona penghambatan sebesar 3,5-6,8 mm. Pada pengujian secara in vivo, isolat-isolat tersebut dapat menekan perkembangan penyakit busuk lunak pada ubi kentang sebesar 71,5-86,4%. Isolat yang cenderung menunjukkan penghambatan relatif lebih baik secara in vitro dan in vivo adalah isolat bakteri endofit asal ubi kentang yaitu isolat CK U3 (Lysinibacillus sp.).Kata Kunci: Pengendalian biologi, Bakteri endofit, Pascapanen, Kentang, Penyakit busuk basah

Sign in / Sign up

Export Citation Format

Share Document