scholarly journals ECOLOGICAL STUDIES OF THE WHITE ROOT ROT OF LOQUAT TREES (2) THE RELATION BETWEEN THE ENVIRONMENTAL CONDITIONS AND THE INFECTION

1966 ◽  
Vol 12 ◽  
pp. 117-119
Author(s):  
Ryoh-ichi OHGUSHI ◽  
Takahiko OHTA ◽  
Toshikatsu NISHINO ◽  
Tsuyuji HIRANO
1965 ◽  
Vol 11 ◽  
pp. 34-35
Author(s):  
Ryoh-ichi OHGUSHI ◽  
Toshikatsu NISHINO ◽  
Takahiko OHTA ◽  
Tsuyuji HIRANO

Rhizosphere ◽  
2020 ◽  
Vol 15 ◽  
pp. 100221
Author(s):  
Imran Shabbir ◽  
Mohd Yusoff Abd Samad ◽  
Radziah Othman ◽  
Mui-Yun Wong ◽  
Zulkefly Sulaiman ◽  
...  

1951 ◽  
Vol 4 (3) ◽  
pp. 211
Author(s):  
GC Wade

The disease known as white root rot affects raspberries, and to a less extent loganberries, in Victoria. The causal organism is a white, sterile fungus that has not been identified. The disease is favoured by dry soil conditions and high soil temperatures. It spreads externally to the host by means of undifferentiated rhizomorphs; and requires a food base for the establishment of infection. The spread of rhizomorphs through the soil is hindered by high soil moisture content and consequent poor aeration of the soil.


Author(s):  
Zunwei Ke ◽  
Gaolei Cai ◽  
Fan Zhang ◽  
Jianhua Gong ◽  
Yang Zhou ◽  
...  

2009 ◽  
Vol 83 (24) ◽  
pp. 12801-12812 ◽  
Author(s):  
Sotaro Chiba ◽  
Lakha Salaipeth ◽  
Yu-Hsin Lin ◽  
Atsuko Sasaki ◽  
Satoko Kanematsu ◽  
...  

ABSTRACT White root rot, caused by the ascomycete Rosellinia necatrix, is a devastating disease worldwide, particularly in fruit trees in Japan. Here we report on the biological and molecular properties of a novel bipartite double-stranded RNA (dsRNA) virus encompassing dsRNA-1 (8,931 bp) and dsRNA-2 (7,180 bp), which was isolated from a field strain of R. necatrix, W779. Besides the strictly conserved 5′ (24 nt) and 3′ (8 nt) terminal sequences, both segments show high levels of sequence similarity in the long 5′ untranslated region of approximately 1.6 kbp. dsRNA-1 and -2 each possess two open reading frames (ORFs) named ORF1 to -4. Although the protein encoded by 3′-proximal ORF2 on dsRNA-1 shows sequence identities of 22 to 32% with RNA-dependent RNA polymerases from members of the families Totiviridae and Chrysoviridae, the remaining three virus-encoded proteins lack sequence similarities with any reported mycovirus proteins. Phylogenetic analysis showed that the W779 virus belongs to a separate clade distinct from those of other known mycoviruses. Purified virions ∼50 nm in diameter consisted of dsRNA-1 and -2 and a single major capsid protein of 135 kDa, which was shown by peptide mass fingerprinting to be encoded by dsRNA-1 ORF1. We developed a transfection protocol using purified virions to show that the virus was responsible for reduction of virulence and mycelial growth in several host strains. These combined results indicate that the W779 virus is a novel bipartite dsRNA virus with potential for biological control (virocontrol), named Rosellinia necatrix megabirnavirus 1 (RnMBV1), that possibly belongs to a new virus family.


2019 ◽  
Vol 34 (3) ◽  
pp. 340-343
Author(s):  
Hayato Shiragane ◽  
Toshiyuki Usami ◽  
Masahiro Shishido

2018 ◽  
Vol 85 (3) ◽  
Author(s):  
Clara Pliego ◽  
José Ignacio Crespo-Gómez ◽  
Adrián Pintado ◽  
Isabel Pérez-Martínez ◽  
Antonio de Vicente ◽  
...  

ABSTRACTThe rhizobacteriumPseudomonas pseudoalcaligenesAVO110, isolated by the enrichment of competitive avocado root tip colonizers, controls avocado white root rot disease caused byRosellinia necatrix. Here, we applied signature-tagged mutagenesis (STM) during the growth and survival of AVO110 in fungal exudate-containing medium with the goal of identifying the molecular mechanisms linked to the interaction of this bacterium withR. necatrix. A total of 26 STM mutants outcompeted by the parental strain in fungal exudate, but not in rich medium, were selected and namedgrowth-attenuatedmutants (GAMs). Twenty-one genes were identified as being required for this bacterial-fungal interaction, including membrane transporters, transcriptional regulators, and genes related to the metabolism of hydrocarbons, amino acids, fatty acids, and aromatic compounds. The bacterial traits identified here that are involved in the colonization of fungal hyphae include proteins involved in membrane maintenance (a dynamin-like protein and ColS) or cyclic-di-GMP signaling and chemotaxis. In addition, genes encoding a DNA helicase (recB) and a regulator of alginate production (algQ) were identified as being required for efficient colonization of the avocado rhizosphere.IMPORTANCEDiseases associated with fungal root invasion cause a significant loss of fruit tree production worldwide. The bacteriumPseudomonas pseudoalcaligenesAVO110 controls avocado white root rot disease caused byRosellinia necatrixby using mechanisms involving competition for nutrients and niches. Here, a functional genomics approach was conducted to identify the bacterial traits involved in the interaction with this fungal pathogen. Our results contribute to a better understanding of the multitrophic interactions established among bacterial biocontrol agents, the plant rhizosphere, and the mycelia of soilborne pathogens.


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