scholarly journals A Novel Ourmia-Like Mycovirus Confers Hypovirulence-Associated Traits on Fusarium oxysporum

2020 ◽  
Vol 11 ◽  
Author(s):  
Ying Zhao ◽  
Yuanyan Zhang ◽  
Xinru Wan ◽  
Yuanyuan She ◽  
Min Li ◽  
...  

Fusarium wilt caused by Fusarium oxysporum f. sp. momordicae (FoM) is an important fungal disease that affects the production of bitter gourd. Hypovirulence-associated mycoviruses have great potential and application prospects for controlling the fungal disease. In this study, a novel ourmia-like virus, named Fusarium oxysporum ourmia-like virus 1 (FoOuLV1), was isolated from FoM strain HuN8. The viral genomic RNA is 2,712 nucleotides (nt) in length and contains an open reading frame (ORF) encoding a putative RNA-dependent RNA polymerase (RdRp) using either standard or mitochondrial codes. In strain HuN8, there was also a FoOuLV1-associated RNA segment with 1,173 nt in length with no sequence homology. Phylogenetic analysis showed that FoOuLV1 is a member of the genus Magoulivirus of the family Botourmiaviridae. FoOuLV1 was found to be associated with hypovirulence in FoM. Moreover, FoOuLV1 and its hypovirulence trait can be transmitted horizontally to other FoM strains and also to other formae speciale strains of F. oxysporum. In addition, FoOuLV1 showed significant biological control effect against the bitter gourd Fusarium wilt. To our knowledge, this study reveals the first description of a hypovirulence-associated ourmia-like mycovirus, which has the potential to the biological control of Fusarium wilt.

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2026
Author(s):  
Caiyi Wen ◽  
Xinru Wan ◽  
Yuanyuan Zhang ◽  
Hongyan Du ◽  
Chenxing Wei ◽  
...  

A novel mycovirus named Fusarium oxysporum alternavirus 1(FoAV1) was identified as infecting Fusarium oxysporum strain BH19, which was isolated from a fusarium wilt diseased stem of Lilium brownii. The genome of FoAV1 contains four double-stranded RNA (dsRNA) segments (dsRNA1, dsRNA 2, dsRNA 3 and dsRNA 4, with lengths of 3.3, 2.6, 2.3 and 1.8 kbp, respectively). Additionally, dsRNA1 encodes RNA-dependent RNA polymerase (RdRp), and dsRNA2- dsRNA3- and dsRNA4-encoded hypothetical proteins (ORF2, ORF3 and ORF4), respectively. A homology BLAST search, along with multiple alignments based on RdRp, ORF2 and ORF3 sequences, identified FoAV1 as a novel member of the proposed family “Alternaviridae”. Evolutionary relation analyses indicated that FoAV1 may be related to alternaviruses, thus dividing the family “Alternaviridae” members into four clades. In addition, we determined that dsRNA4 was dispensable for replication and may be a satellite-like RNA of FoAV1—and could perhaps play a role in the evolution of alternaviruses. Our results provided evidence for potential genera establishment within the proposed family “Alternaviridae”. Additionally, FoAV1 exhibited biological control of Fusarium wilt. Our results also laid the foundations for the further study of mycoviruses within the family “Alternaviridae”, and provide a potential agent for the biocontrol of diseases caused by F. oxysporum.


1987 ◽  
Vol 33 (5) ◽  
pp. 349-353 ◽  
Author(s):  
T. C. Paulitz ◽  
C. S. Park ◽  
R. Baker

Nonpathogenic isolates of Fusarium oxysporum were obtained from surface-disinfested, symptomless cucumber roots grown in two raw (nonautoclaved) soils. These isolates were screened for pathogenicity and biological control activity against Fusarium wilt of cucumber in raw soil infested with Fusarium oxysporum f. sp. cucumerinum (F.o.c.). The influence of three isolates effective in inducing suppressiveness and three ineffective isolates on disease incidence over time was tested. The effective isolates reduced the infection rate (R), based on linear regressions of data transformed to loge (1/1 – y). Effective isolate C5 was added to raw soil infested with various inoculum densities of F.o.c. In treatments without C5, the increase in inoculum densities of F.o.c. decreased the incubation period of wilt disease, but there was no significant difference in infection rate among the inoculum density treatments. Isolate C5 reduced the infection rate at all inoculum densities of F.o.c. Various inoculum densities of C5 were added to raw soils infested with 1000 cfu/g of F.o.c. In the first trial, infection rates were reduced only in the treatment with 10 000 cfu/g of C5; in the second trial, infection rates were reduced in treatments with 10 000 and 30 000 cfu/g of C5.


Pathogens ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 43 ◽  
Author(s):  
Arfe Castillo ◽  
Cecirly Puig ◽  
Christian Cumagun

Philippine banana is currently threatened by Fusarium oxysporum f. sp. cubense Tropical Race 4 (FocR4). This study investigated the use of Trichoderma harzianum pre-treated with Glomus spp, as a means of managing Fusarium wilt on young ‘Lakatan’ banana seedlings. Results showed that Glomus applied basally significantly improved banana seedling growth with increased increment in plant height and pseudostem diameter and heavier root weight. The application of Glomus spp. alone offered 100% protection to the ‘Lakatan’ seedlings against FocR4 as indicated by the absence of the wilting symptom. A combination of T. harzianum and Glomus spp. also gave significant effect against Fusarium wilt through delayed disease progression in the seedlings but was not synergistic. Competitive effects were suspected when application of the two biological control agents on banana roots was done simultaneously.


2018 ◽  
Author(s):  
Rui Zang ◽  
Ying Zhao ◽  
Kangdi Guo ◽  
Kunqi Hong ◽  
Huijun Xi ◽  
...  

AbstractThe bitter gourd fusarium wilt caused by Fusarium oxysporum f.sp. momordicae (FOM) was a devastating disease in China and leading to great economic losses every year. A total of 152 isolates, which have the typical Fusarium oxysporum characteristics with abundant microconidia and macroconidia on the white or ruby colonies, were obtained from diseased plant tissues with typical fusarium wilt symptoms. The BLASTn analysis of rDNA-ITS showed 99% identity with F.oxysporum species. Among the tested isolates, three isolates infected tower gourd, and five isolates were pathogenic to bottle gourd. However, they were all pathogenic to bitter gourd. Based on the molecular and morphologic results, the isolates were identified as FOM. For genetic variation analysis, forty ISSR primers were screened and eleven primers were used in PCR amplification. Totally, 121 loci were detected, of which 52 loci were polymorphic at rate of 42.98%. The POPGENE analysis showed that Nei’s gene diversity index (H) and Shannon’s information index (I) were 0.0902 and 0.1478, respectively, which indicated that the genetic diversity for the tested 152 isolates was relatively low. It also means that each geographical population was a relatively independent unit. While the value of coefficient of gene differentiation (Gst=0.4929 > 0.15) pointed to the genetic differentiation was mainly among populations. The strength of gene flow (Nm=0.5143<1.0) was weaker, indicating that gene exchanges were blocked to some degree. The dendrogram based on ISSR markers showed that the eight geographical populations were clustered into four groups at the threshold of genetic similar coefficient 0.96. Fujian, Jiangxi and Guangdong populations were clustered into Group I. Group II contained Hunan and Guangxi populations. Group III only had Hainan population. Group IV consisted Shandong and Henan populations. The geographical populations closer to each other grouped together, suggesting a correlationship between geographical origin and genetic differentiation. Two hybridization events were observed between Hainan and Hunan populations and between Guangdong and Guangxi by Structure analysis. Our findings enrich the knowledge on genetic variation characteristics of the FOM populations with helpful of development of effective disease management programs and disease resistance breeding.


2013 ◽  
Vol 15 (1) ◽  
pp. 21
Author(s):  
Hadiwiyono Hadiwiyono ◽  
Arief Widyantoro ◽  
Salim Widono

<p>Fusarium wilt (Fusarium oxysporum f.sp. cubense) is an important disease in banana. Fusarium wilt was hard to control because the pathogen can survive in many kind of soils type although there is no host. Therefore, overcoming the disease is urgently needed such as biological control. The endophytic Bacillus of banana was begun to use as antagonist agent to the pathogen. This research aimed to study the mechanism of antagonism and physiological character of Bacillus. There were 27 Bacillus isolates examined in-vitro to test the production of IAA, HCN, chitinase, pectinase, and antagonism. The top ten isolates based on the test in vitro were used to test in planta. The research showed that Bacillus were able to produce IAA, HCN, chitinase, pectinase, and able to retard the growth of Foc colony. The application of isolat B25 on banana seedling could decrease the disease intensity but still unable to prevent the fusarium wilt infection.</p>


2020 ◽  
Vol 9 (6) ◽  
pp. 249-254
Author(s):  
Mokhtaria Tlemsani ◽  
Zohra Fortas ◽  
Soulef Dib ◽  
Miloud Bellahcen

Vascular wilt caused by Fusarium oxysporum f. sp. ciceri (FOC) is a disease that limits the yield of chickpea in Algeria. Biological control with antagonistic microorganisms is one of the alterna ves methods to ght this fungal disease. In this work, we tested an ac nomycete Streptomyces ACT2 against 03 isolates of FOC (FOC8, FOC13, FOC 15) in vivo on three varie es of chick- pea including a sensi ve variety (ILC-482) and two varie es moderately tole- rant (Col-27, PPC-25) in order to highlight its effect on the reduc on or suppression of this disease. The results obtained showed that the degree of suppression of the disease by ACT2 varies from one variety to another and from one FOC isolate to another. The maximum suppression of the disease was observed in the Col-27 variety. The ACT2 isolate showed higher levels of disease suppression in both the moderately sensi ve Col-27 (13.68%) and PPC- 25 (18.78%) varie es than the sensitive variety ILC-482 (8.76%). The Streptomyces (ACT2) can be used as a biological protector of chickpea infected by the pathogen Fusarium oxysporum f. sp. ciceri.


2016 ◽  
Vol 69 ◽  
pp. 57-63 ◽  
Author(s):  
H. Ghazalibiglar ◽  
D.R.W. Kandula ◽  
J.G. Hampton

Th is study investigated the ability of ten Trichoderma isolates to control the fusarium wilt pathogen of tomato Fusarium oxysporum f sp lycopersici as well as the eff ect of these isolates on tomato plant growth in the presence and absence of the pathogen The isolates were obtained from the Lincoln BioProtection Research Centre Culture Collection and were inoculated into seed raising mix (05 w/w) in two glasshouse studies Two Trichoderma isolates significantly (P


Viruses ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 231 ◽  
Author(s):  
Jia Zhou ◽  
Yuhua Wang ◽  
Xiaofei Liang ◽  
Changping Xie ◽  
Wenbo Liu ◽  
...  

Here, we report a novel (+) ssRNA mycovirus, Phoma matteucciicola ourmia-like virus 1 (PmOLV1), isolated from Phoma matteucciicola strain LG915-1. The genome of PmOLV1 was 2603 nucleotides long and contained a single open reading frame (ORF), which could be translated into a product of RNA-dependent RNA polymerase (RdRp) by both standard and mitochondrial genetic codons. Cellular fractionation assay indicated that PmOLV1 RNAs are likely more enriched in mitochondria than in cytoplasm. Phylogenetic analysis indicated that PmOLV1 is a new member of the genus Penoulivirus (recently proposed) within the family Botourmiaviridae.


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