Correction to: Evaluating an isotonic aqueous formulation of Chaetomium globosum Kunze for the management of potato black scurf disease caused by Rhizoctonia solani Kuhn in India

A survey of anastomosis groups (AG) of Rhizoctonia spp. associated with potato diseases was conducted in South Africa. In total, 112 Rhizoctonia solani and 19 binucleate Rhizoctonia (BNR) isolates were recovered from diseased potato plants, characterized for AG and pathogenicity. The AG identity of the isolates was confirmed using phylogenetic analysis of the internal transcribed spacer region of ribosomal DNA. R. solani isolates recovered belonged to AG 3-PT, AG 2-2IIIB, AG 4HG-I, AG 4HG-III, and AG 5, while BNR isolates belonged to AG A and AG R, with frequencies of 74, 6.1, 2.3, 2.3, 0.8, 12.2, and 2.3%, respectively. R. solani AG 3-PT was the most predominant AG and occurred in all the potato-growing regions sampled, whereas the other AG occurred in distinct locations. Different AG grouped into distinct clades, with high maximum parsimony and maximum-likelihood bootstrap support for both R. solani and BNR. An experiment under greenhouse conditions with representative isolates from different AG showed differences in aggressiveness between and within AG. Isolates of AG 2-2IIIB, AG 4HG-III, and AG R were the most aggressive in causing stem canker while AG 3-PT, AG 5, and AG R caused black scurf. This is the first comprehensive survey of R. solani and BNR on potato in South Africa using a molecular-based approach. This is the first report of R. solani AG 2-2IIIB and AG 4 HG-I causing stem and stolon canker and BNR AG A and AG R causing stem canker and black scurf on potato in South Africa.

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Transcriptional Changes in Potato Sprouts upon Interaction with Rhizoctonia solani Indicate Pathogen-Induced Interference in the Defence Pathways of Potato

International Journal of Molecular Sciences ◽

10.3390/ijms22063094 ◽

2021 ◽

Vol 22 (6) ◽

pp. 3094

Author(s):

Rita Zrenner ◽

Bart Verwaaijen ◽

Franziska Genzel ◽

Burkhardt Flemer ◽

Rita Grosch

Keyword(s):

Rhizoctonia Solani ◽

Rna Sequencing ◽

Control Strategies ◽

Transcriptional Response ◽

Black Scurf ◽

Post Inoculation ◽

Molecular Response ◽

Resistance Level ◽

Sequencing Experiment ◽

Transcriptional Changes

Rhizoctonia solani is the causer of black scurf disease on potatoes and is responsible for high economical losses in global agriculture. In order to increase the limited knowledge of the plants’ molecular response to this pathogen, we inoculated potatoes with R. solani AG3-PT isolate Ben3 and carried out RNA sequencing with total RNA extracted from potato sprouts at three and eight days post inoculation (dpi). In this dual RNA-sequencing experiment, the necrotrophic lifestyle of R. solani AG3-PT during early phases of interaction with its host has already been characterised. Here the potato plants’ comprehensive transcriptional response to inoculation with R. solani AG3 was evaluated for the first time based on significantly different expressed plant genes extracted with DESeq analysis. Overall, 1640 genes were differentially expressed, comparing control (−Rs) and with R. solani AG3-PT isolate Ben3 inoculated plants (+Rs). Genes involved in the production of anti-fungal proteins and secondary metabolites with antifungal properties were significantly up regulated upon inoculation with R. solani. Gene ontology (GO) terms involved in the regulation of hormone levels (i.e., ethylene (ET) and jasmonic acid (JA) at 3 dpi and salicylic acid (SA) and JA response pathways at 8 dpi) were significantly enriched. Contrastingly, the GO term “response to abiotic stimulus” was down regulated at both time points analysed. These results may support future breeding efforts toward the development of cultivars with higher resistance level to black scurf disease or the development of new control strategies.

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Management of Black Scurf (Rhizoctonia solani) of Potato through Organic Approaches

Indian Journal of Agricultural Research ◽

10.18805/ijare.a-5465 ◽

2020 ◽

Author(s):

Narendra Singh ◽

Vikee M. Patel

Keyword(s):

Boric Acid ◽

Rhizoctonia Solani ◽

Tuber Yield ◽

Disease Incidence ◽

Organic Amendments ◽

Black Scurf ◽

Economic Losses ◽

Research Station ◽

Diseased Tuber ◽

Tuber Treatment

Black scurf (Rhizoctonia solani) disease of potato is becoming prominent in many potato growing districts of Gujarat state which reduce quality and market value of the produce, resulting in economic losses. The field experiment was conducted during rabi season of 2014-15 in naturally infested field with scurf pathogen at Potato Research Station, S.D. Agricultural University, Deesa (Gujarat) with the objective to find out suitable management strategies for black scurf through organic approaches (bio-agents and organic amendments). Among different bio-agents (Trichoderma viride, T. harzianum. Pseudomonas fluorescens and Bacillus subtilis) tested against black scurf, the tuber treatment with 2 per cent boric acid spray along with tuber treatment with T. viride @ 10 g/kg seed before sowing recorded the lowest disease incidence (15.33 %) and index (0.38) with highest total tuber yield (324.68 q/ha) with maximum income `2,57,414/ha. When price computed with healthy and diseased tuber yield among treatments, the maximum income variation was (`92,986/ha) recorded by the same treatment followed by the tuber treatment with 3 % boric acid spray before sowing (`68,440/ha). In case of various organic amendments tested, soil application of mustard cake @ 10 q/ha registered minimum disease incidence (37.33 %) and disease index (0.66) as compared to rest of the organic treatment with highest total tuber yield (`327.20 q/ha) with maximum income `2,65,010/ha. When price computed with healthy and diseased tuber yield among treatments, the maximum income variation was (`1,12,990/ha) recorded by the same treatment followed by the neem cake @ 10 q/ha (`56,660/ha). These organic treatments can provide an effective and economical management of black scurf of potato for cultivaters.

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Screening of Potato Varieties against Black Scurf Caused by Rhizoctonia solani Kuhn

International Journal of Current Microbiology and Applied Sciences ◽

10.20546/ijcmas.2021.1001.171 ◽

2021 ◽

Vol 10 (01) ◽

pp. 1444-1449

Author(s):

Prashant Kumar Singh ◽

Jagdish Kumar Patidar ◽

Reeti Singh ◽

S. Roy

Keyword(s):

Rhizoctonia Solani ◽

Black Scurf ◽

Potato Varieties

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Anastomosis Grouping of Rhizoctonia solani Associated with Black Scurf and Stem Canker of Potato in South Africa

Plant Disease ◽

10.1094/pdis.2004.88.1.83b ◽

2004 ◽

Vol 88 (1) ◽

pp. 83-83 ◽

Cited By ~ 8

Author(s):

M. Truter ◽

F. C. Wehner

Keyword(s):

South Africa ◽

Rhizoctonia Solani ◽

Rating Scale ◽

Solanum Tuberosum L ◽

Potato Cultivar ◽

Stem Canker ◽

Potato Production ◽

Black Scurf ◽

Chi Square ◽

Chi Square Analysis

Rhizoctonia disease (black scurf of tubers and stem canker) of potato (Solanum tuberosum L.) caused by Rhizoctonia solani Kühn was first recorded in South Africa in 1918 (3). Although the sclerotial form on tubers is one of the most common potato diseases in the country, it is not known which anastomosis groups (AGs) of R. solani are involved. Between 1999 and 2001, R. solani was isolated from 28 plant and 56 soil samples collected in 7 (Eastern Free State, Gauteng, KwaZulu-Natal, Limpopo, Mpumalanga, Northern Cape, and Sandveld) of the 14 potato-production regions of South Africa and screened for hyphal anastomosis with tester strains of R. solani AG-1 to AG-10 according to Carling et al. (1). Of the 411 isolates from tubers with black scurf symptoms, 408 were AG-3 and three were AG-5. Symptomless tubers yielded two AG-3 isolates and three AG-5 isolates. Of 39 isolates from symptomatic stems and roots, 32 were AG-3, five were AG-4, and two were AG-5. Of the 127 isolates obtained from soil, 86, 28, 7, 3, and 3 were AG-3, AG-4, AG-5, AG-7, and AG-8, respectively. More than one AG was isolated from five of the seven regions. Virulence of 40 isolates representative of the above AGs was determined in triplicate on sprouts growing from seed tubers of potato cultivar Up-to-Date in a sand/soil mixture as described by Carling and Leiner (2) but using cultures grown in cornmeal/sand instead of colonized agar disks as inoculum. Damage to sprouts (lesions, girdling, and death) was assessed after 28 days at 16 to 28°C according to the 0 to 4 rating scale (2). Chi-square analysis of the data indicated that AG-3 was the most virulent, with isolates from sclerotia on tubers and lesions on stems more aggressive than those from symptomless tubers or soil. AG-4 and AG-5 caused significantly less disease than AG-3, but none of the AG-7 and AG-8 isolates showed any virulence to potato sprouts. References: (1) D. E. Carling et al. Phytopathology 77:1609, 1987. (2) D. E. Carling and R. H. Leiner. Phytopathology 80:930, 1990. (3) E. M. Doidge. S. Afr. Fruit Growers 5:6, 1918.

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First Report of Black Scurf Caused by Rhizoctonia solani AG-3 on Potato Tubers in Mauritius

Plant Disease ◽

10.1094/pdis-06-20-1183-pdn ◽

2021 ◽

Vol 105 (1) ◽

pp. 213

Author(s):

S. D. Takooree ◽

H. Neetoo ◽

V. M. Ranghoo-Sanmukhiya ◽

S. Hardowar ◽

J. E. van der Waals ◽

...

Keyword(s):

Rhizoctonia Solani ◽

Black Scurf ◽

Potato Tubers ◽

First Report

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Rhizoctonia solani Anastomosis Group 3 is Predominant in Potato Tubers in Poland

Plant Disease ◽

10.1094/pdis-05-12-0482-pdn ◽

2013 ◽

Vol 97 (9) ◽

pp. 1245-1245 ◽

Cited By ~ 1

Author(s):

J. W. Woodhall ◽

B. Lutomirska ◽

J. C. Peters ◽

P. S. Wharton

Keyword(s):

Rhizoctonia Solani ◽

Tap Water ◽

Anastomosis Group ◽

Black Scurf ◽

Crop Rotations ◽

Potato Tubers ◽

Hyphal Fusion ◽

Group 3 ◽

Plant Pathol ◽

Potato Crops

Rhizoctonia solani is a species complex of 13 related but genetically distinct anastomosis groups (AGs). In potato, R. solani can infect the stems, stolons, and roots, resulting in quantitative losses. It can also cause qualitative losses through blemishes occurring on progeny tubers, such as black scurf and elephant hide (corky cracking). Knowledge of the AG in local populations is important because they differ in host range, fungicide sensitivity, and disease severity (2). To determine the AGs present in Poland, 54 tuber samples displaying typical R. solani symptoms were taken from six different fields in 2011. The fields were representative of five different administrative regions of Poland and from at least 10 different varieties. Rhizoctonia was isolated from tubers by placing symptomatic material on to tap water agar amended with streptomycin and penicillin and after 2 to 3 days Rhizoctonia colonies were identified and hyphal tips of these transferred to potato dextrose agar. Rhizoctonia was successfully isolated from 48 tubers displaying black scurf and two tubers displaying elephant hide symptoms. DNA was extracted from Rhizoctonia cultures using a Wizard Food kit (Promega) and the AG was determined using specific real-time PCR assays (1). All Rhizoctonia isolates were determined to be AG3 and this was confirmed for 10 selected isolates by observing hyphal fusion with a known AG3 tester isolate (Rs08) as described previously (3). Pairings were also conducted amongst the 10 Polish isolates, C2 reactions were typically observed indicating numerous vegetative compatible groups are present. This study shows that AG3 is likely to be the predominant AG in potato tubers in Poland. This is similar to other studies in Europe, which have all determined that AG3 accounts for at least 92% of isolates from potato (2,3). AG2-1, 4, and 5 have also been found in tubers worldwide and climate and certain crop rotations can influence the presence of these other AGs in potato tubers (2). However, climate and crop rotations in Poland are similar to other parts of Europe so the predominance of AG3 is expected. AG3 was also isolated from elephant hide symptoms; however, it was more frequently isolated from sclerotia. The ability of AG3 to prolifically produce sclerotia and thereby survive on seed tubers may explain its predominance in potato crops (4). Therefore, studies focusing on the management of Rhizoctonia potato disease in Poland should consider AG3 in the first instance. References: (1) G. E. Budge et al. Plant Pathol. 58:1071, 2009. (2) L. Tsror. J. Phytopathol. 158:649, 2010. (3) J. W. Woodhall et al. Plant Pathol. 56:286, 2007. (4) J. W. Woodhall et al. Plant Pathol. 57:5, 2008.

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