scholarly journals First report of Fusarium solani Species Complex Causing Root Rot of Loquat (Eriobotrya japonica) in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Di Wu ◽  
Danhua Zhang ◽  
Caixia Wang ◽  
Yue Wei ◽  
Michael Paul Timko ◽  
...  

Loquat (Eriobotrya japonica), a native fruit tree to China, is a popular edible fruit with medicinal properties (Badenes et al. 2013). A 2016-2019 field survey of ~13,000 loquat trees in two orchards in Chongqing and Fujian provinces showed about 5 to 10% root rot disease incidence. The disease symptoms included leaf yellowing, wilting, rotting of main root, and cracking of lateral roots, eventually leading to defoliation and death. To determine the causative agent, diseased roots from six trees were collected, washed in tap water, cut into 2-3 mm pieces, and disinfected for 3 min in 75% (v/v) EtOH. After rinsing in sterilized water, the root pieces were soaked in 10% NaClO (w/v) for 5-10 min, rinsed thrice in sterile water, and plated on potato dextrose agar (PDA). After 7 days of incubation at 25°C, individual spores were collected from the fungal colonies and replated. Single spore cultures growing on PDA gave rise to woolly-cottony, cream-white colored aerial mycelium and a yellowish pigmented mycelium. The average colony growth rate was 8.6 mm day-1 (n=3). Microscopic observation of the mycelium revealed septate and hyaline hyphae and long cylindrical monophialides. Macroconidia were moderately curved, stout, 3-4 septate, measuring 20.79-48.70 μm × 4.16-10.14 μm (n=50). Microconidia produced from long phialides were kidney-shaped, 0-2 septate, and 5.72-17.28 μm × 2.29-6.51 μm (n=50) in size. The mycelial characteristics and reproductive structures of the isolates fit the morphological description of Fusarium sp. (Summerell et al. 2003). To confirm this identification, translation elongation factor (EF-1α) and RNA polymerase I beta subunit (RPB1) and RNA polymerase II beta subunit (RPB2) regions of the genome were PCR amplified from 3 separate isolates (R2, R4 and R5) using EF1/ EF2, RPB1-Fa/G2R, RPB2-5f2/7cR & RPB2-7cF/11aR primer pairs (O’Donnell et al. 2010) and sequenced. BLASTn comparison of the EF-1α (MT976167), RPB1 (MT967271) and RPB2 (MW233052) regions from isolate R4 showed 99% identity with the EF-1α (GU170620, 675/676 bp), RPB1 (KC808270, 1543/1545 bp) and RPB2 (MK4419902, 1637/1638 bp) sequences of Fusarium solani species complex (FSSC) in GenBank database. The same species level identification was also found using FUSARIUM-ID and FUSARIUM-MLDT databases. Two-year-old seedlings (n=3) of two different cultivars, ‘Hunanzaoshu’ and ‘Huabai No. 1’, growing in pots indoors at 25-27 °C were inoculated by drenching the soil with a conidial suspension of isolate R4 (40 mL, 106 conidia mL-1 obtained from 6-10 day old cultures). Control plants (n=3) were inoculated with sterilized water. At 20 days after inoculation (DAI) the leaves of inoculated plants became chlorotic and wilted, defoliated over time, and by 53 DAI 91.67% of plants died. The taproot and lateral roots of inoculated plants appeared brown to black in color and most lateral roots died and decomposed at 53 DAI, whereas the control plant roots remained healthy. All control plants remained symptomless. Based on morphological and molecular characters (TEF-1, RPB1 and RPB2), the re-isolated pathogen from diseased plants was identical to the R4 isolate used for inoculation and the disease assays were repeated thrice. FSSC was recently reported to cause fruit rot disease on loquat in Pakistan (Abbas et al. 2017). Identifying Fusarium solani species complex as a disease agent in Chinese loquat will assist in future development of improved germplasm for this important worldwide tree crop.

Plant Disease ◽  
2012 ◽  
Vol 96 (7) ◽  
pp. 1067-1067 ◽  
Author(s):  
V. Gupta ◽  
D. John ◽  
V. K. Razdan ◽  
S. K. Gupta

Bunium persicum (Kala zeera, also black cumin) is an economically important culinary crop that is cultivated for its seed pods and its tuberlike roots. In India, high-altitude regions of Himachal Pradesh, including the Padder valley and the Gurez area of Jammu and Kashmir, are areas of kalazeera production (3). In 2008 to 2009, tuber rot disease of kala zeera was observed during the late spring season in the Padder valley. Symptomatic plants were distributed in localized areas in the field and the symptoms included drying of foliage and rotting of tubers. White mycelia were found on the tubers at the late stages of disease development. Incidence of infection in the surveyed area was 80 to 90%. Yield losses were 50 to 60%. To isolate the causal pathogen, we cultured tissues from symptomatic tubers. Small bits of the infected tissue were surface disinfested in 0.1% mercuric chloride, followed by rinsing three times in sterile distilled water. The surface disinfested tissues were plated on potato dextrose agar (PDA) and incubated at 27°C for 4 days. Pure cultures of the mycelium from the diseased tissues were transferred to a second set of PDA for species identification. The fungus produced three types of spores: small, one-celled, oval microconidia; large, slightly curved, septate macroconidia; and rounded, thick-walled chlamydospores. Microconidia were mostly non-septate and 8.91 to 15.73 × 2.3 to 3.5 μm, whereas macroconidia were three- to five-septate and were 35.55 to 54.74 × 3.91 to 6.5 μm. On the basis of morphological characteristics (1), the fungus was identified and deposited as a member of the Fusarium solani species complex in the Indian Type Culture Collection, New Delhi (ID No. 8422.11). To confirm pathogenicity, healthy tubers were submerged for 20 min in a conidial suspension of the isolated fungus (1 × 105 cfu/ml), which was prepared in potato dextrose broth, incubated for 10 days at 27°C, and centrifuged at 140 rpm. Noninoculated controls were submerged in distilled water. Inoculated and control tubers were then planted in separate pots filled with sterilized soil and kept in a shade house. Symptoms appeared on inoculated tubers 9 to 10 days after planting. Signs of the pathogen in the form of mycelia were present. The tubers rotted and died 12 to 15 days after inoculation. Control tubers did not display any symptoms. F. solani species complex was reisolated from inoculated tubers, fulfilling Koch's postulates. F. solani has been reported to cause corm rot on gladiolus and saffron (2). To our knowledge, this is the first report of the F. solani species complex as pathogenic to tubers of kalazeera in India. References: (1) C. Booth. The Genus Fusarium. 47, 1971. (2) L. Z. Chen et al. J. Shanghai Agric. College 12:240, 1994. (3) K. S. Panwar et al. Agriculture Situation in India. 48:151, 1993.


Plant Disease ◽  
2016 ◽  
Vol 100 (8) ◽  
pp. 1784 ◽  
Author(s):  
M. P. Melo ◽  
J. E. A. Beserra ◽  
K. S. Matos ◽  
C. S. Lima ◽  
O. L. Pereira

Plant Disease ◽  
2016 ◽  
Vol 100 (10) ◽  
pp. 2171-2171 ◽  
Author(s):  
C. S. Cabral ◽  
M. P. Melo ◽  
M. E. N. Fonseca ◽  
L. S. Boiteux ◽  
A. Reis

2011 ◽  
Vol 77 (2) ◽  
pp. 132-135 ◽  
Author(s):  
Keisuke Tomioka ◽  
Yuuri Hirooka ◽  
Akane Takezaki ◽  
Takayuki Aoki ◽  
Toyozo Sato

Plant Disease ◽  
2021 ◽  
Author(s):  
Sixto Velarde Felix ◽  
Victor Valenzuela ◽  
Pedro Ortega ◽  
Gustavo Fierros ◽  
Pedro Rojas ◽  
...  

Chickpea (Cicer aretinium L.) is a legume crop of great importance worldwide. In January 2019, wilting symptoms on chickpea (stunted grow, withered leaves, root rot and wilted plants) were observed in three fields of Culiacan Sinaloa Mexico, with an incidence of 3 to 5%. To identify the cause, eighty symptomatic chickpea plants were sampled. Tissue from roots was plated on potato dextrose agar (PDA) medium. Typical Fusarium spp. colonies were obtained from all root samples. Ten pure cultures were obtained by single-spore culturing (Ff01 to Ff10). On PDA the colonies were abundant with white aerial mycelium, hyphae were branched and septae and light purple pigmentation was observed in the center of old cultures (Leslie and Summerell 2006). From 10-day-old cultures grown on carnation leaf agar medium, macroconidias were falciform, hyaline, with slightly curved apexes, three to five septate, with well-developed foot cells and blunt apical cells, and measured 26.6 to 45.8 × 2.2 to 7.0 μm (n = 40). The microconidia (n = 40) were hyaline, one to two celled, produced in false heads that measured 7.4 to 20.1 (average 13.7) μm × 2.4 to 8.9 (average 5.3) μm (n = 40) at the tips of long monophialides, and were oval or reniform, with apexes rounded, 8.3 to 12.1 × 1.6 to 4.7 μm; chlamydospores were not evident. These characteristics fit those of the Fusarium solani (Mart.) Sacc. species complex, FSSC (Summerell et al. 2003). The internal transcribed spacer and the translation elongation factor 1 alpha (EF1-α) genes (O’Donnell et al. 1998) were amplified by polymerase chain reaction and sequenced from the isolate Ff02 and Ff08 (GenBank accession nos. KJ501093 and MN082369). Maximum likelihood analysis was carried out using the EF1-α sequences (KJ501093 and MN082369) from the Ff02 and Ff08 isolates and other species from the Fusarium solani species complex (FSSC). Phylogenetic analysis revealed the isolate most closely related with F. falciforme (100% bootstrap). For pathogenicity testing, a conidial suspension (1x106 conidia/ml) was prepared by harvesting spores from 10-days-old cultures on PDA. Twenty 2-week-old chickpea seedlings from two cultivars (P-2245 and WR-315) were inoculated by dipping roots into the conidial suspension for 20 min. The inoculated plants were transplanted into a 50-hole plastic tray containing sterilized soil and maintained in a growth chamber at 25°C, with a relative humidity of >80% and a 12-h/12-h light/dark cycle. After 8 days, the first root rot symptoms were observed on inoculating seedlings and the infected plants eventually died within 3 to 4 weeks after inoculation. No symptoms were observed plants inoculated with sterilized distilled water. The fungus was reisolated from symptomatic tissues of inoculated plants and was identified by sequencing the partial EF1-α gene again and was identified as F. falciforme (FSSC 3 + 4) (O’Donnell et al. 2008) based on its morphological characteristics, genetic analysis, and pathogenicity test, fulfilling Koch’s postulates. The molecular identification was confirmed via BLAST on the FusariumID and Fusarium MLST databases. Although FSSC has been previously reported causing root rot in chickpea in USA, Chile, Spain, Cuba, Iran, Poland, Israel, Pakistan and Brazil, to our knowledge this is the first report of root rot in chickpea caused by F. falciforme in Mexico. This is important for chickpea producers and chickpea breeding programs.


Plant Disease ◽  
2021 ◽  
Author(s):  
Yihua Yang ◽  
Zhenyan Cao ◽  
Jintian Tang ◽  
Yang Song ◽  
Xuping Shentu ◽  
...  

Dendrobium officinale Kimura et Migo is a rare and valuable Chinese herb cultivated in Zhejiang and Yunnan Provinces, China, which is known for its functions as an anti-neoplastic and for lowering the blood sugar (Cheng et al., 2019). In September and October of 2018 and 2019, symptoms of root rot on D. officinale were observed with an incidence of 15–20% in Wuyi County, Zhejiang Province, China. The pathogen mainly infected roots causing severe root rot, which resulted in significant economic losses. At the early stage of this disease, the stalk turned brown, then the whole plant rotted from bottom to top within a few days. Symptomatic roots were cut into small pieces (1.0 cm × 1.0 cm) and disinfected successively by submersion in 75% ethanol for 30 s and 1% NaClO for 30 s under aseptic conditions. After rinsing with sterile water three times and air drying, segments were placed on potato dextrose agar (PDA). After incubation at 25 °C for 5 d in the dark, white to pale cream colored colonies were produced. The average mycelial growth rate was 15.2–18.5 mm day-1 at 25 ℃. Macroconidia were falciform with three to five septa and (18.0−32.0)×(3.0−5.0) μm in size. Microconidia were fusiform with two to three septa (7.0–10.0)×(2.1–3.0) μm. Based on morphological characteristics of macroconidia, and microconidia, isolates were identified as Fusarium incarnatum-equiseti species complex (span style="font-family:'Times New Roman'; font-size:12pt">FIESC) (Avila et al., 2019). The internal transcribed spacer (ITS) region, translation elongation factor (EF-1α), RNA polymerase largest subunit (RPB1), and RNA polymerase second largest subunit (RPB2) gene were amplified and sequenced respectively using ITS1/ITS4, EF1/EF2, Fa/G2R and 5f2/7cr primers (O’Donnell et al., 2010). BLASTN analysis of FUSARIUM-ID using ITS (Accession NO. MW172977), EF-1α (Accession NO. MW172978, RPB1(Accession NO. MW172979), and RPB2(Accession NO. MW172980) showed 99.8%, 100%, 99.74%, and 98.63% identity to FIESC isolates NRRL43619, NRRL34059, NRRL32864, and NRRL32175, respectively. To verify pathogenicity, ten 1-year-old healthy D. officinale plants were used for inoculation tests. One milliliter of a conidial suspension (106 conidia ml-1) was pipetted onto the soil around the base of D. officinale plants per pot. Ten plants, which were treated with sterile water, were used as the control. All plants were maintained in a climatic chamber (26 ± 1 ℃, 70–80% relative humidity and a photoperiod of 16:8 [L: D] h). Seven days later, all inoculated plants showed typical symptoms of root rot identical to those observed in the fields. Control plants remained symptomless and healthy. The pathogenicity analysis was repeated three times. Pathogens re-isolated from symptomatic plants were identified as FIESC species by morphology observation and sequence analysis. To our knowledge, this is the first report of root rot caused by FIESC species on D. officinale in Zhejiang, China.


2016 ◽  
Vol 120 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Sarah S. Costa ◽  
Kedma S. Matos ◽  
Dauri J. Tessmann ◽  
Claudine D.S. Seixas ◽  
Ludwig H. Pfenning

Plant Disease ◽  
2019 ◽  
Vol 103 (9) ◽  
pp. 2470 ◽  
Author(s):  
Y. H. Zhou ◽  
Y. L. Liu ◽  
X. G. Yin ◽  
J. N. Lu ◽  
J. R. Tang

Plant Disease ◽  
2018 ◽  
Vol 102 (2) ◽  
pp. 327-333 ◽  
Author(s):  
Periasamy Chitrampalam ◽  
Nivi Abraham ◽  
Berlin D. Nelson

Fusarium solani species complex (FSSC) 11 is the primary phylogenetic species of FSSC causing root rot in soybean in the north-central United States. A polymerase chain reaction (PCR)-based assay was developed to identify and differentiate FSSC 11 from the less aggressive FSSC 5 and other Fusarium and Pythium spp. associated with soybean roots. The primer set FSSC11-F and FSSC11-R designed from the RNA polymerase second largest subunit gene yielded the expected amplicon of about 900 bp with DNA from all 22 FSSC 11 isolates tested in PCR. However, it did not produce an amplicon with DNA from 29 isolates of FSSC 5, seven other Fusarium spp., three Pythium spp., and soybean tested in PCR. Furthermore, the primer set successfully detected FSSC 11 from a DNA mixture containing the DNA of FSSC 11, FSSC 5, other Fusarium spp., and soybean. The primer set also detected FSSC 11 from both soil and soybean roots. Additionally, the prevalence of FSSC 11 in soybean roots was determined in five fields in North Dakota by both a culture-independent PCR approach with FSSC11-F and FSSC11-R and a culture-dependent approach. Results from both the culture-dependent and culture-independent approaches with FSSC11-F and FSSC11-R were consistent and revealed the presence of the FSSC 11 in three of five fields sampled.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Alemayehu Dugassa ◽  
Tesfaye Alemu ◽  
Yitbarek Woldehawariat

Abstract Background Faba bean (Vicia faba L.) cultivation is highly challenged by faba bean black root rot disease (Fusarium solani) in high lands of Ethiopia. To ensure sustainable production of faba beans, searching for eco-friendly disease management options is necessary to curb the progress of the disease timely. The indigenous biocontrol agents that suit local environments may effectively strive with in-situ microorganisms and suppress local pathogen strains. This study aimed to screen antagonistic indigenous compatible Trichoderma and Pseudomonas strains against Fusarium solani. In the pathogenicity test, soil-filled pots were arranged in complete random block design and sown with health faba bean seeds. The effect of some fungicides was evaluated against Fusarium by food poisoning methods to compare with the biocontrol agents. The antagonistic efficacy of biocontrol agents and their compatibility was investigated on Potato dextrose agar medium. Results Fusarium solani AAUF51 strain caused an intense root rotting in faba bean plant. The effect of Mancozeb 80% WP at 300 ppm was comparable with Trichoderma and Pseudomonas strains against Fusarium. The mycelial growth of test the pathogen was significantly (P ≤ 0.05) reduced to 86.67 and 85.19% by Trichoderma harzianum AAUW1 and Trichoderma viridae AAUC22 strains in dual culture, respectively. The volatile metabolites of Pseudomonas aeruginosa AAUS31 (77.78%) found the most efficient in reducing mycelial growth of Fusarium followed by Pseudomonas fluorescens AAUPF62 (71.11%) strains. The cell-free culture filtrates of Pseudomonas fluorescens AAUPF62 and Pseudomonas aeruginosa AAUS31 were more efficient than the Trichoderma strain in reducing the growth of Fusarium isolates. There was no zone of inhibition recorded between Trichoderma harzianum AAUW1, Trichoderma viridae AAUC22, Pseudomonas aeruginosa AAUS31, and Pseudomonas fluorescens AAUPF62 strains, hence they were mutually compatible. Conclusions The compatible Trichoderma and Pseudomonas strains showed antagonistic potentiality that could be explored for faba bean protection against black root rot disease and might have a future dual application as biocontrol agents.


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