PRELIMINARY STUDIES ON THE SEXUAL STAGE OF RHIZOCTONIA SOLANI KÜHN

1953 ◽  
Vol 31 (6) ◽  
pp. 699-710 ◽  
Author(s):  
E. J. Hawn ◽  
T. C. Vanterpool
Keyword(s):  
Rhizoctonia Solani ◽  
Parent Strain ◽  
Sexual Stage ◽  
Diploid Nucleus ◽  
Single Spore ◽  
Perfect Stage ◽  
Rich Media ◽  
Close Relationship ◽  
Germ Tubes ◽  
Growth Characters

The perfect stage of a flax strain of Rhizoctonia solani Kühn was obtained fairly consistently on artificial media. In growth characters and morphological dimensions, it agreed closely with those of Pellicularia filamentosa (Pat.) Rogers, except that its sterigmata averaged three times as long (26 μ). This latter character suggests close relationship to Corticium praticola Kotila. Single-basidiospore cultures differed among themselves and from the parent strain in morphology, cultural characters, growth rates, and pathogenicity on Royal flax. Some single-spore cultures produced the perfect stage, although preliminary pairings of sterile single-spore cultures remained sterile. This isolate is thus heterozygous and homothallic. There appear to be 12 chromosomes in the diploid nucleus in the basidium. The mature basidiospore is predominantly uninucleate; occasionally a binucleate basidiospore is observed. Germination is by repetition on plain agar, or by germ tubes on rich media. Those basidiospores which germinate by repetition are commonly uninucleate and give rise to uninucleate secondary basidiospores. Basidiospore discharge is by the drop excretion mechanism. To determine the identity of the flax strain, it will be necessary to produce the perfect stage of the flax strain on natural substrates or the perfect stage of P. filamentosa on artificial media.

NOTES ON THE CANADIAN TUCKAHOE, ITS OCCURRENCE IN CANADA AND THE INTERFERTILITY OF ITS PERFECT STAGE, POLYPORUS TUBERASTER JACQ. EX FRIES

1951 ◽  
Vol 29 (2) ◽  
pp. 147-157 ◽  
Author(s):  
T. C. Vanterpool ◽  
Ruth Macrae
Keyword(s):  
Populus Tremuloides ◽  
Western Canada ◽  
Single Spore ◽  
Canadian Prairies ◽  
Perfect Stage

The Canadian tuckahoe is the perennial sclerotium of Polyporus tuberaster jacq. ex Fries. It is commonly found in the parkland belt of the Canadian prairies where land supporting, virgin poplar groves, mainly Populus tremuloides Michx., is being brought under cultivation. Sporophore as many as three to a single sclerotium, appear in late June and July. Interfertility studies with single spore cultures isolated from sporophores derived from four sources in Western Canada and from one source in Italy have shown that both the Canadian fungus and the European P. tuberaster are heterothallic, have the tetrapolar type of interfertility, and are interfertile.

SYNTHESIS OF HETEROKARYONS IN RHIZOCTONIA SOLANI KÜHN

1963 ◽  
Vol 41 (6) ◽  
pp. 879-886 ◽  
Author(s):  
H. S. Whitney ◽  
J. R. Parmeter Jr.
Keyword(s):  
Rhizoctonia Solani ◽  
Single Spore ◽  
Wide Range ◽  
Cultural Types

The single-spore progeny of an isolate of Rhizoctonia solani showed a wide range of cultural types. When these progeny were paired by plating on opposite sides of Petri plates or by mixing semiliquid cultures, certain combinations gave rise to heterokaryons. The heterokaryons originated from hyphal anastomoses and were culturally distinct from either of the contributing homokaryons. Observations suggested a bipolar coaipatibility mechanism among the homokaryons. Some homokaryotic strains fruited, yielding culturally indistinguishable progeny. These homothallic lines also formed heterokaryons with other homothallic lines. The progeny of these heterokaryons showed a wide range of cultural types, indicating that some homokaryons could fruit either homothallically or heterothallically.

scholarly journals Identification and Characterization of Three Monilinia Species from Plum in China

Plant Disease ◽  
2015 ◽  
Vol 99 (12) ◽  
pp. 1775-1783 ◽  
Author(s):  
Liang-Fen Yin ◽  
Shu-Ning Chen ◽  
Guo-Kang Chen ◽  
Guido Schnabel ◽  
Sheng-Fang Du ◽  
...  
Keyword(s):  
Brown Rot ◽  
Single Spore ◽  
Chongqing Municipality ◽  
Prunus Salicina ◽  
Size Number ◽  
Colony Color ◽  
Rot Disease ◽  
Germ Tubes ◽  
Colony Shape

In total, 112 Monilinia spp. single-spore isolates were collected from plum fruit (Prunus salicina) symptomatic for brown rot disease from Yunnan, Hubei, and Zhejiang provinces and Chongqing municipality, China between 2012 and 2014. Three distinct colony morphologies (phenotypes) were observed on potato dextrose agar and two isolates per phenotype were selected for further analysis. Colony color, colony shape, conidia size, number of germ tubes per conidia, and pathogenicity on plum were investigated. The ribosomal internal transcribed spacer regions 1 and 2 as well as a polymerase chain reaction-based method that amplified fragments of the glyceraldehyde-3-phosphate dehydrogenase (G3PDH) and β-tubulin (TUB2) genes were used to identify the isolates to the species level. The three phenotypes were identified to be three different species: Monilinia fructicola, Monilia mumecola, and Monilia yunnanensis. Phylogenetic analysis based on G3PDH and TUB2 nucleotide sequences revealed that isolates within species clustered together regardless of host or geographical origin, suggesting that these factors did not play an important role for the evolutionary separation of the described species.

Nuclear behavior and clarification of the spore stages of Uromyces koae

1981 ◽  
Vol 59 (5) ◽  
pp. 939-946 ◽  
Author(s):  
Donald E. Gardner
Keyword(s):  
Life Cycle ◽  
Meiotic Division ◽  
Germ Tube ◽  
Nuclear Staining ◽  
Diploid Nucleus ◽  
Spore Type ◽  
Acacia Koa ◽  
Nuclear Behavior ◽  
Germ Tubes

Recent observations showed that Uromyces koae Arthur in Stevens teliospores did not produce typical basidia or basidio-spores. The present study reveals that teliospores produced long germ tubes that are differentiated into wide proximal and narrow distal portions separated by a vesiclelike swelling. One or two extensive branches, each morphologically resembling the main tube, developed from individual germ tube cells. Nuclear staining revealed a single, presumably diploid nucleus in mature teliospores. One or more probable mitotic divisions in the main germ tube provided a diploid nucleus for each branch and for the main tube itself. Meiotic division of each nucleus produced a series of four smaller nuclei in the narrow portion of each branch and the main tube. The germ tubes may be modified basidia and serve as infectious hyphae in place of basidiospores.A formerly undescribed spore type associated with the teliospores is recognized as uredinial. This investigation shows that the life cycle of U. koae probably consists of four distinct stages, each on Acacia koa: the spermatial associated with the aecial on hypertrophied shoots, and the uredinial and telial together in discrete leaf pustules.

SURVIVAL OF SINGLE-BASIDIOSPORE ISOLATES OF RHIZOCTONIA PRATICOLA AND RHIZOCTONIA SOLANI

1964 ◽  
Vol 10 (5) ◽  
pp. 739-746 ◽  
Author(s):  
George C. Papavizas
Keyword(s):  
Organic Matter ◽  
Rhizoctonia Solani ◽  
High Tolerance ◽  
Single Spore ◽  
Time Rate ◽  
Unamended Soil ◽  
Parent Culture ◽  
Oat Straw ◽  
Rhizoctonia Praticola ◽  
Rate Of Decline

Twenty randomly selected single-basidiospore isolates from each of Rhizoctonia praticola and R. solani differed considerably in their tolerance to CO2, competitive saprophytic activity, and ability to survive within precolonized substrate segments incubated in soils with or without pentachloronitrobenzene (PCNB) or oat straw. With a few exceptions, isolates possessing high saprophytic activity also possessed high tolerance to CO2 and high surviving ability in precolonized substrate. Several single-spore isolates of R. solani possessed higher ability for saprophytic survival in organic matter and lower CO2-sensitivity than their parent culture. Survival of single-basidiospore isolates in precolonized substrate segments was greater in unamended soil or soil amended with oat straw than in soil treated with PCNB. Mature oat straw reduced surviving ability of several isolates, whereas it increased surviving ability of others above that observed in unamended soil. The isolates whose surviving ability was increased by oat straw were mostly those possessing high saprophytic activity in unamended soil. Saprophytic activity and virulence of all isolates tested declined with time. Rate of decline of virulence was much more rapid for weak than strong saprophytes.

PHIALOPHORA RADICICOLA CAIN, A CORN ROOTROT PATHOGEN

1952 ◽  
Vol 30 (3) ◽  
pp. 344-347 ◽  
Author(s):  
W. E. McKeen
Keyword(s):  
Rhizoctonia Solani ◽  
Potato Dextrose Agar ◽  
Root Tissue ◽  
Sexual Stage ◽  
Corn Roots ◽  
Infected Root ◽  
Infection Threads ◽  
Agar Media ◽  
Host Relations ◽  
Apparently Healthy

During the summer of 1950, Phialophora radicicola, was found on corn roots in soil near Chatham, Ridgetown, and Harrow, Ont. Owing to its color and parasite-host relations, it may have been mistaken previously for Rhizoctonia solani or a Rhizophagus species. It can be isolated only when a piece of apparently healthy corn root tissue with the adhering mycelium is removed from an infected root and placed on agar media. After two or three months of culture on nutrient and on potato dextrose agar, P. radicicola lost its ability to sporulate, but this ability was revived when it was cultured on moist corn roots. No sexual stage of the organism has been found. The fungus may attack corn roots at any time throughout the season and its brown runner-hyphae or macrohyphae grow parallel to the roots. The finer infection hyphae or microhyphae penetrate the outer root tissue and their infection threads are surrounded by "wall tubules". The fungus is quite aggressive, but not very pathogenic, and apparently it is followed by numerous secondary organisms. The similarity of this organism to Ophiobolus graminis is very noticeable.

PHYSIOLOGICAL AND CYTOLOGICAL STUDIES OF BASIDIOSPORE REPETITION IN RHIZOCTONIA SOLANI KÜHN

1964 ◽  
Vol 42 (10) ◽  
pp. 1397-1404
Author(s):  
H. S. Whitney
Keyword(s):  
Rhizoctonia Solani ◽  
Germ Tube ◽  
Thanatephorus Cucumeris ◽  
Germ Tubes

Mycelium of a clone of Thanatephorus cucumeris (Frank) Donk (Rhizoctonia solani Kühn) produced ether-soluble substances which, when incorporated into water agar, caused basidiospores to shift from germ tube development to repetition. Repetition activity was localized in chromatograms by bioassay. Germ tubes less than 48 hours old produced ballistospores when transferred from water agar to fruiting cultures. Cells of older hyphae had apparently lost this capacity. Repetition spores, and ballistospores produced by germ tubes, were uninucleate and gave rise to cultures typical of the parent fungus. The relevance of repetition to survival and to phylogeny was discussed.

A NEW FIXATIVE AND IMPROVED PROPIONOCARMINE SQUASH TECHNIQUE FOR STAINING FUNGUS NUCLEI

1962 ◽  
Vol 40 (6) ◽  
pp. 843-847 ◽  
Author(s):  
Benjamin C. Lu
Keyword(s):  
Acetic Acid ◽  
Neurospora Crassa ◽  
Nuclear Division ◽  
Chromic Acid ◽  
Butyl Alcohol ◽  
Sexual Stage ◽  
Mitotic Figures ◽  
Improved Technique ◽  
Germ Tubes

A new fixative, which is composed of butyl alcohol, acetic acid, and chromic acid, is introduced. This BAC mixture fixes nuclear details, and cytoplasm is not granulated to any extent. Details of staining procedures and helpful hints for successful staining are given. This improved technique differentiates all stages of nuclear division from interphase to interphase in the vegetative hyphae of fungi as well as in the sexual stage. Chromosomes, nucleoli, and centrioles are clearly shown. A series of mitotic figures in germ tubes of Neurospora crassa and some meiotic figures in Gelasinospora calospora are attached as illustrations.

The transition from germ tubes to vegetative growth in uredospores of Melampsora lini

1991 ◽  
Vol 69 (8) ◽  
pp. 1715-1718 ◽  
Author(s):  
R. Boasson ◽  
M. Shaw
Keyword(s):  
Vegetative Growth ◽  
Mycelial Growth ◽  
Rust Fungus ◽  
Axenic Culture ◽  
Single Spore ◽  
Naked Eye ◽  
Melampsora Lini ◽  
Rate Of Increase ◽  
Germ Tubes ◽  
Spore Densities

The transition from uredospore germ tubes to vegetative hyphae marks the initiation of mycelial colonies of Melampsora lini growing in axenic culture. It is promoted by heat shock (31 °C for 2 h) and is arbitrarily defined as having occurred when mitotic divisions of the two original uredospore nuclei have produced more than four nuclei. The percentage of germinating spores in which it occurs (percentage initiation) does not increase beyond 48 h after seeding and is higher (about 9 vs. 5%) at a low (18 spores/mm2) than at a higher (90 spores/mm2) inoculum density. The number of nuclei in a mycelial colony arising from a single uredospore increases exponentially with a mean doubling time of 2.40 days. Neither the percentage initiation nor the rate of increase in number of nuclei (= mycelial growth) are affected by the proximity of neighbouring spores at spore densities of the order of 18 spores/mm2. Approximately 10% of the initiated colonies exhibit a growth rate that renders them visible to the naked eye after 5 weeks. Key words: rust fungus, axenic culture, vegetative growth, single spore colonies.

scholarly journals Disruption of the Trichoderma reesei gul1 gene stimulates hyphal branching and reduces broth viscosity in cellulase production

2021 ◽  
Author(s):  
Qinqin Zhao ◽  
Qin Liu ◽  
Qi Wang ◽  
Yuqi Qin ◽  
Yaohua Zhong ◽  
...  
Keyword(s):  
Trichoderma Reesei ◽  
Filamentous Fungi ◽  
Parent Strain ◽  
Fermentation Broth ◽  
Cellulase Production ◽  
Lower Viscosity ◽  
Close Relationship ◽  
Genes Encoding ◽  
Lateral Branches ◽  
Mrna Binding

Abstract Hyphal morphology is considered to have a close relationship with the production level of secreted proteins by filamentous fungi. In this study, the gul1 gene, which encodes a putative mRNA-binding protein, was disrupted in cellulase-producing fungus Trichoderma reesei. The hyphae of Δgul1 strain produced more lateral branches than the parent strain. Under the condition for cellulase production, disruption of gul1 resulted in smaller mycelial clumps and significantly lower viscosity of fermentation broth. In addition, cellulase production was improved by 22% relative to the parent strain. Transcriptome analysis revealed that a set of genes encoding cell wall remodeling enzymes as well as hydrophobins were differentially expressed in the Δgul1 strain. The results suggest that the regulatory role of gul1 in cell morphogenesis is likely conserved in filamentous fungi. To our knowledge, this is the first report on the engineering of gul1 in an industrially important fungus.

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