scholarly journals Divergence Between Sympatric Rice- and Soybean-Infecting Populations of Rhizoctonia solani Anastomosis Group-1 IA

2008 ◽  
Vol 98 (12) ◽  
pp. 1326-1333 ◽  
Author(s):  
Joana Bernardes de Assis ◽  
Patrik Peyer ◽  
Milton C. Rush ◽  
Marcello Zala ◽  
Bruce A. McDonald ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Anastomosis Group ◽  
Sheath Blight ◽  
Host Specialization ◽  
Rice Sheath Blight ◽  
Sympatric Populations ◽  
Migration Patterns ◽  
Hardy Weinberg Equilibrium ◽  
Internal Transcribed Spacer Rdna ◽  
Group 1

Rhizoctonia solani anastomosis group (AG)-1 IA causes soybean foliar blighting (aerial blight) and rice sheath blight diseases. Although taxonomically related within the AG-1 complex, sister populations of R. solani AG-1 IA infecting Poaceae (rice) and Fabaceae (soybean) are genetically distinct based on internal transcribed spacer rDNA. However, there is currently no information available regarding the extent of genetic differentiation and host specialization between rice- and soybean-infecting populations of R. solani AG-1 IA. We used 10 microsatellite loci to compare sympatric R. solani AG-1 IA populations infecting rice and soybeans in Louisiana and one allopatric rice-infecting population from Texas. None of the 154 multilocus genotypes found among the 223 isolates were shared among the three populations. Partitioning of genetic diversity showed significant differentiation among sympatric populations from different host species (ΦST = 0.39 to 0.41). Historical migration patterns between sympatric rice- and soybean-infecting populations from Louisiana were asymmetrical. Rice- and soybean-derived isolates of R. solani AG-1 IA were able to infect both rice and soybean, but were significantly more aggressive on their host of origin, consistent with host specialization. The soybean-infecting population from Louisiana was more clonal than the sympatric rice-infecting population. Most of the loci in the soybean-infecting populations were out of Hardy-Weinberg equilibrium (HWE), but the sympatric rice-infecting population from Louisiana was mainly in HWE. All populations presented evidence for a mixed reproductive system.

scholarly journals Divergence Between Sympatric Rice- and Maize-Infecting Populations of Rhizoctonia solani AG-1 IA from Latin America

2010 ◽  
Vol 100 (2) ◽  
pp. 172-182 ◽  
Author(s):  
A. D. González-Vera ◽  
J. Bernardes-de-Assis ◽  
M. Zala ◽  
B. A. McDonald ◽  
F. Correa-Victoria ◽  
...  
Keyword(s):  
Latin America ◽  
Rhizoctonia Solani ◽  
Reproductive System ◽  
Reproductive Mode ◽  
Host Shift ◽  
Anastomosis Group ◽  
Sheath Blight ◽  
Host Specialization ◽  
Sympatric Populations ◽  
Basidiomycetous Fungus

The basidiomycetous fungus Rhizoctonia solani anastomosis group (AG)-1 IA is a major pathogen in Latin America causing sheath blight (SB) of rice. Particularly in Venezuela, the fungus also causes banded leaf and sheath blight (BLSB) on maize, which is considered an emerging disease problem where maize replaced traditional rice-cropping areas or is now planted in adjacent fields. Our goals in this study were to elucidate (i) the effects of host specialization on gene flow between sympatric and allopatric rice and maize-infecting fungal populations and (ii) the reproductive mode of the fungus, looking for evidence of recombination. In total, 375 isolates of R. solani AG1 IA sampled from three sympatric rice and maize fields in Venezuela (Portuguesa State) and two allopatric rice fields from Colombia (Meta State) and Panama (Chiriquí State) were genotyped using 10 microsatellite loci. Allopatric populations from Venezuela, Colombia, and Panama were significantly differentiated (ΦST of 0.16 to 0.34). Partitioning of the genetic diversity indicated differentiation between sympatric populations from different host species, with 17% of the total genetic variation distributed between hosts while only 3 to 6% was distributed geographically among the sympatric Venezuelan fields. We detected symmetrical historical migration between the rice- and the maize-infecting populations from Venezuela. Rice- and maize-derived isolates were able to infect both rice and maize but were more aggressive on their original hosts, consistent with host specialization. Because the maize- and rice-infecting populations are still cross-pathogenic, we postulate that the genetic differentiation was relatively recent and mediated via a host shift. An isolation with migration analysis indicated that the maize-infecting population diverged from the rice-infecting population between 40 and 240 years ago. Our findings also suggest that maize-infecting populations have a mainly recombining reproductive system whereas the rice-infecting populations have a mixed reproductive system in Latin America.

scholarly journals Draft Genome Sequence of Rhizoctonia solani Anastomosis Group 1 Subgroup 1A Strain 1802/KB Isolated from Rice

2017 ◽  
Vol 5 (43) ◽  
Author(s):  
Kalaivani Nadarajah ◽  
Nurhani Mat Razali ◽  
Boon Huat Cheah ◽  
Nur Syafiqah Sahruna ◽  
Ismanizan Ismail ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Genome Sequence ◽  
Rice Variety ◽  
Draft Genome ◽  
Anastomosis Group ◽  
Sheath Blight ◽  
Draft Genome Sequence ◽  
Content Type ◽  
Group 1

ABSTRACT Sheath blight, caused by Rhizoctonia solani anastomosis group 1 subgroup 1A (AG1-1A), is one of the most devastating rice diseases worldwide. Here, we report the draft genome sequence of R. solani AG1-1A strain 1802/KB isolated from a popular Malaysian rice variety. To the best of our knowledge, this is the second reported representative genome from AG1-1A.

scholarly journals Strategies to Manage Rice Sheath Blight: Lessons from Interactions between Rice and Rhizoctonia solani

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Dayong Li ◽  
Shuai Li ◽  
Songhong Wei ◽  
Wenxian Sun
Keyword(s):  
Rhizoctonia Solani ◽  
Anastomosis Group ◽  
Sheath Blight ◽  
Phytopathogenic Fungus ◽  
Blight Resistance ◽  
Rice Sheath Blight ◽  
Resistance Qtls ◽  
Necrotrophic Pathogen ◽  
Worldwide Distribution ◽  
Sheath Blight Resistance

AbstractRhizoctonia solani is an important phytopathogenic fungus with a wide host range and worldwide distribution. The anastomosis group AG1 IA of R. solani has been identified as the predominant causal agent of rice sheath blight, one of the most devastating diseases of crop plants. As a necrotrophic pathogen, R. solani exhibits many characteristics different from biotrophic and hemi-biotrophic pathogens during co-evolutionary interaction with host plants. Various types of secondary metabolites, carbohydrate-active enzymes, secreted proteins and effectors have been revealed to be essential pathogenicity factors in R. solani. Meanwhile, reactive oxygen species, phytohormone signaling, transcription factors and many other defense-associated genes have been identified to contribute to sheath blight resistance in rice. Here, we summarize the recent advances in studies on molecular interactions between rice and R. solani. Based on knowledge of rice-R. solani interactions and sheath blight resistance QTLs, multiple effective strategies have been developed to generate rice cultivars with enhanced sheath blight resistance.

Effects of straw incorporation on Rhizoctonia solani inoculum in paddy soil and rice sheath blight severity

2013 ◽  
Vol 152 (5) ◽  
pp. 741-748 ◽  
Author(s):  
H. ZHU ◽  
Z. X. WANG ◽  
X. M. LUO ◽  
J. X. SONG ◽  
B. HUANG
Keyword(s):  
Rhizoctonia Solani ◽  
Disease Severity ◽  
Rice Straw ◽  
Paddy Soil ◽  
Sheath Blight ◽  
Soil Productivity ◽  
Rice Sheath Blight ◽  
Important Method ◽  
Pathogen Dynamics ◽  
Straw Incorporation

SUMMARYIncorporation of rice straw into soil has traditionally been an important method of recycling nutrients and improving soil productivity. Currently, although the effects of straw incorporation on disease severity have been documented, the dynamics of the pathogen in soil after straw incorporation are poorly understood. In the present study, rice straw with various proportions of diseased straw was incorporated at three separate locations (SuPu town, SuSong County and FengYang County) in Anhui province, China. The pathogen dynamics in paddy soil and disease severity of sheath blight during two continuous years from April 2010 to April 2012 were investigated. For all three locations, the amount of pathogen inoculum that persisted in the soil increased with increases in the proportion of diseased straw incorporated. Incorporation of 0·3 and 0·5 diseased straw into soil increased the amount of pathogen inoculum in the soil significantly, whereas incorporation of 0·1 diseased straw into soil had no significant effect on the pathogen inoculum compared with the control (no straw incorporated) or disease severity. Incorporation of healthy rice straw (no disease) resulted in a significant decrease in disease severity, whereas proportions of 0·3 and 0·5 diseased straw resulted in a significant increase of disease severity compared with the control. These results suggested that incorporation of diseased straw enhanced pathogen numbers in soil during the whole decomposition period and increased disease severity. To avoid soil-borne disease accumulation, severely diseased straw should be removed from the field or pre-treated before incorporation.

Functional analysis of polygalacturonase gene RsPG2 from Rhizoctonia solani, the pathogen of rice sheath blight

2017 ◽  
Vol 149 (2) ◽  
pp. 491-502 ◽  
Author(s):  
Xijun Chen ◽  
Li Lili ◽  
Yun Zhang ◽  
Jiahao Zhang ◽  
Shouqiang Ouyang ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Rhizoctonia Solani ◽  
Sheath Blight ◽  
Rice Sheath Blight ◽  
Polygalacturonase Gene

Highly polymorphic microsatellite loci in the rice- and maize-infecting fungal pathogen Rhizoctonia solani anastomosis group 1 IA

2008 ◽  
Vol 8 (3) ◽  
pp. 686-689 ◽  
Author(s):  
M. ZALA ◽  
B. A. MCDONALD ◽  
J. BERNARDES DE ASSIS ◽  
M. B. CIAMPI ◽  
M. STORARI ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Microsatellite Loci ◽  
Fungal Pathogen ◽  
Anastomosis Group ◽  
Polymorphic Microsatellite ◽  
Group 1

scholarly journals Rhizoctonia solani AG-1 IA infects both rice and signalgrass in the Colombian Llanos

2016 ◽  
Vol 46 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Lina Maria Ramos-Molina ◽  
Edisson Chavarro-Mesa ◽  
Danilo Augusto dos Santos Pereira ◽  
María del Rosario Silva-Herrera ◽  
Paulo Cezar Ceresini
Keyword(s):  
Rhizoctonia Solani ◽  
Species Complex ◽  
Molecular Detection ◽  
Sheath Blight ◽  
Pathogenicity Test ◽  
Rice Sheath Blight ◽  
Specific Primers ◽  
5.8S Rdna ◽  
Foliar Blight ◽  
Rhizoctonia Oryzae

ABSTRACT Foliar blight and death of signalgrass (Urochloa spp.) pastures are caused by the Rhizoctonia solani fungus. This study aimed at determining which pathogens from the Rhizoctonia species complex are associated with leaf and sheath blight in Urochloa and rice, in the Colombian Llanos. Sympatric areas of Urochloa pastures adjacent to rice cropping areas were sampled using a linear transect system. The pathogens were identified using morphological traits, molecular detection based on specific primers and sequencing of the ITS-5.8S rDNA region. R. solani AG-1 IA predominated as the pathogen associated with foliar blight in all samples from U. brizantha cv. 'Toledo' and hybrid Urochloa cv. 'Mulato'. Besides R. solani AG-1 IA (18 % of the samples), Rhizoctonia oryzae-sativae (71 %) and Sclerotium hydrophilum (11 %) were also detected. In the cross-pathogenicity test, the R. solani AG-1 IA fungus was the most aggressive to Urochloa, while R. oryzae-sativae produced very mild infection symptoms. This is the first report of R. oryzae-sativae and S. hydrophilum associated with the complex of rice sheath blight diseases in Colombia.

Sign in / Sign up

Export Citation Format

Share Document