THE BLACK ROOTROT DISEASE OF TOBACCO.: II. PHYSIOLOGIC SPECIALIZATION OF THIELAVIOPSIS BASICOLA ON NICOTIANA TABACUM

1950 ◽  
Vol 28c (6) ◽  
pp. 726-738 ◽  
Author(s):  
R. H. Stover
Keyword(s):  
Nicotiana Tabacum ◽  
Potato Dextrose Agar ◽  
Thielaviopsis Basicola ◽  
Wild Type ◽  
Physiologic Specialization ◽  
Physiologic Races

Thielaviopsis basicola (Berk. & Br.) Ferraris exists in nature in two distinct forms, termed the brown and the gray wild type, which are differentiated on potato dextrose agar. Pathogenicity on tobacco was found to be a function of the wild type culture used. All gray wild type cultures were less pathogenic than the brown. The brown wild type cultures consisted of at least two physiologic races. Race I is found in the "old belt" of Ontario, and in Quebec, Ohio, and Connecticut. Race II is present in the "new belt" of Ontario and in Kentucky. Race II and all gray wild type cultures are less pathogenic than Race I. All cultural mutants were less pathogenic than wild type cultures.

BEHAVIOR OF ALBINISM IN BROWN AND GRAY CULTURES OF THIELAVIOPSIS BASICOLA

1956 ◽  
Vol 34 (6) ◽  
pp. 875-879 ◽  
Author(s):  
R. H. Stover
Keyword(s):  
Gene Mutation ◽  
Enzyme System ◽  
Potato Dextrose Agar ◽  
Phenotypic Change ◽  
Thielaviopsis Basicola ◽  
Wild Type ◽  
Single Spore ◽  
Cytoplasmic Enzyme ◽  
Gene Type ◽  
Genotypic Control

Many single spore gray wild type cultures of Thielaviopsis basicola consistently produce an average of 3.5–4.2 albino sectors after 5–10 days growth at 73° ± 3° F. on potato dextrose agar and other media. Sectoring was greatly reduced at fluctuating room temperatures of 76°–87° F. and on certain media. Mass spore transfers from the albino sectors yield albino colonies with a small pigmented area around the center of transfer. Single spore cultures of the albino sectors inevitably revert to the gray parent. In contrast to the gray, brown type cultures rarely produce albino sectors or patches and these yield pure albino colonies that have remained stable for four years. All albino colonies are identical morphologically to the parents except in loss of pigment and a retarded thickening of the chlamydospore walls.The expression of albinism in gray type cultures cannot be explained on the basis of a simple gene mutation. Also, an explanation based on a variable phenotypic change, originating in the cytoplasmic enzyme system controlling pigmentation and under constant genotypic control, is not entirely adequate. The expression of albinism in brown type cultures has the characteristics of a gene-type mutation.

THE BLACK ROOTROT DISEASE OF TOBACCO: I. STUDIES ON THE CAUSAL ORGANISM THIELAVIOPSIS BASICOLA

1950 ◽  
Vol 28c (4) ◽  
pp. 445-470 ◽  
Author(s):  
R. H. Stover
Keyword(s):  
Potato Dextrose Agar ◽  
Thielaviopsis Basicola ◽  
Wild Type ◽  
Cell Penetration ◽  
Causal Organism ◽  
Artificial Culture ◽  
Predominant Form ◽  
Cell Colonization ◽  
Thin Walled ◽  
And Behavior

Intensive cultural studies with Thielaviopsis basicola (Berk. & Br.) Ferraris, the cause of the black rootrot disease of tobacco, showed that it exists in nature in two distinct forms, which have been called brown and gray wild types, and which are differentiated by their cultural characteristics on potato dextrose agar. The brown wild type usually is the predominant form isolated, although in some instances the gray predominates in mixed infestations. It is suggested that the balance between the two types is determined, in part, by a differential selective action of the soil flora. The gray wild type is less pathogenic and is more poorly adapted than the brown to withstand long dormant periods. The latter occasionally mutates to the gray in soil, host, and in artificial culture. In a few instances, but only in association with host passage, the gray wild type has mutated to the brown. The wild types do not remain stable on media which support abundant saprophytic growth but give rise to and are crowded out or replaced by cultural mutants. The wild type can be maintained with a minimum of variation in soil, soil agar, roots, or similar substrates (low in certain nutrients). Variations in the morphology and behavior of endoconidia consisted of the production of endoconidial yeastlike colonies and the formation of thick-walled chlamydosporelike structures from thin-walled endoconidia. Some endoconidia are as resistant as chlamydospores to long periods of dormancy, heat, and drying. Fungus morphology in the host was characteristic for each of the three phases of cell penetration, cell colonization, and the production of chlamydospores and endoconidia. Root invasion by Thielavia basicola was common only in association with Thielaviopsis basicola which suggests a commensalistic relationship between these two fungi.

Ultrastructure of Melanin Formation in Curvularia sp., Alternaria sp., and Drechslera Sorokiniana

1977 ◽  
Vol 35 ◽  
pp. 398-399
Author(s):  
M. H. Wheeler ◽  
W. J. Tolmsoff ◽  
A. A. Bell
Keyword(s):  
Potassium Phosphate ◽  
Thielaviopsis Basicola ◽  
Wild Type ◽  
Potassium Phosphate Buffer ◽  
Transmission Microscopy ◽  
Electron Transmission ◽  
Melanin Formation ◽  
Before And After ◽  
Alternaria Sp ◽  
Electron Transmission Microscopy

(+)-Scytalone [3,4-dihydro-3,6,8-trihydroxy-l-(2Hj-naphthalenone] and 1,8-di- hydroxynaphthalene (DHN) have been proposed as intermediates of melanin synthesis in the fungi Verticillium dahliae (1, 2, 3, 4) and Thielaviopsis basicola (4, 5). Scytalone is enzymatically dehydrated by V. dahliae to 1,3,8-trihydroxynaphthalene which is then reduced to (-)-vermelone [(-)-3,4- dihydro-3,8-dihydroxy-1(2H)-naphthalenone]. Vermelone is subsequently dehydrated to DHN which is enzymatically polymerized to melanin.Melanin formation in Curvularia sp., Alternaria sp., and Drechslera soro- kiniana was examined by light and electron-transmission microscopy. Wild-type isolates of each fungus were compared with albino mutants before and after treatment with 1 mM scytalone or 0.1 mM DHN in 50 mM potassium phosphate buffer, pH 7.0. Both chemicals were converted to dark pigments in the walls of hyphae and conidia of the albino mutants. The darkened cells were similar in appearance to corresponding cells of the wild types under the light microscope.

scholarly journals NtRNF217, Encoding a Putative RBR E3 Ligase Protein of Nicotiana tabacum, Plays an Important Role in the Regulation of Resistance to Ralstonia solanacearum Infection

2021 ◽  
Vol 22 (11) ◽  
pp. 5507
Author(s):  
Ying Liu ◽  
Yuanman Tang ◽  
Xi Tan ◽  
Wei Ding
Keyword(s):  
Nicotiana Tabacum ◽  
Ralstonia Solanacearum ◽  
Plant Immunity ◽  
E3 Ligase ◽  
Marker Genes ◽  
Susceptible Cultivar ◽  
Wild Type ◽  
Disease Symptoms ◽  
Short Time ◽  
Resistance To Ralstonia Solanacearum

E3 ubiquitin ligases, the most important part of the ubiquitination process, participate in various processes of plant immune response. RBR E3 ligase is one of the E3 family members, but its functions in plant immunity are still little known. NtRNF217 is a RBR E3 ligase in tobacco based on the sequence analysis. To assess roles of NtRNF217 in tobacco responding to Ralstonia solanacearum, overexpression experiments in Nicotiana tabacum (Yunyan 87, a susceptible cultivar) were performed. The results illuminated that NtRNF217-overexpressed tobacco significantly reduced multiplication of R. solanacearum and inhibited the development of disease symptoms compared with wild-type plants. The accumulation of H2O2 and O2− in NtRNF217-OE plants was significantly higher than that in WT-Yunyan87 plants after pathogen inoculation. The activities of CAT and SOD also increased rapidly in a short time after R. solanacearum inoculation in NtRNF217-OE plants. What is more, overexpression of NtRNF217 enhanced the transcript levels of defense-related marker genes, such as NtEFE26, NtACC Oxidase, NtHIN1, NtHSR201, and NtSOD1 in NtRNF217-OE plants after R. solanacearum inoculation. The results suggested that NtRNF217 played an important role in regulating the expression of defense-related genes and the antioxidant enzymes, which resulted in resistance to R. solanacearum infection.

scholarly journals Lead Phytoremediation Potential of Wild Type and Transgenic Tobacco Plants

2021 ◽  
Vol 5 (1) ◽  
pp. 168-182
Author(s):  
Hatice DAGHAN ◽  
Veli UYGUR ◽  
Abdullah EREN
Keyword(s):  
Nicotiana Tabacum ◽  
Transgenic Tobacco ◽  
Transgenic Tobacco Plants ◽  
Wild Type ◽  
Tobacco Plants ◽  
Nicotiana Tabacum L ◽  
Lead Phytoremediation

Genetiği değiştirilmiş bitkiler, kurşunun (Pb) kökten yer üstü kısımlarına translokasyonunu geliştirmek için büyük bir potansiyele sahip olabilir. Transgenik olmayan ( Nicotiana tabacum L. cv. Petit Havana SR1) ve transgenik (p-cV-ChMTII GFP) tütün bitkileri tarafından Pb alımının sağlanması araştırmak için Çin hamsteri metalotiyonin II gezen bir kap deneyi yapıldı . Transgenik ve transgenik olmayan tütün bitkileri, 0, 1000, 2500, 5000 mg Pb kg- 1 ile Pb (NO 3 ) 2 olarak işlenmiş topraklarda yetiştirildi. Kelimede bir büyüme bölümünde 6 hafta boyunca çiçeklenme aşamasına kadar.Bitkilerin büyümesi, klorofil içeriği, mineral besin elementleri ve düşük glutatyon (GSH) bezleri, bitkilerin Pb alım potansiyeli ile birlikte incelenmiştir. Hem transgenik hem de transgenik olmayan bitkiler için Pb uygulamasındaki artışa bağlı olarak yer üstü biyokütle çevrildi aşamalı bir düşüş gözlendi. Yaprak besinlerinin bulaştığı, aşırı Pb işlemlerinden olumsuz etkilenmiştir, bunlardan en büyük düşüşü. Sürgün Pb yüksek derecesi 76.0 mg kg kadar ulaşan -1 transgenik ve 70.9 mg kg -1 transgenik olmayan bitkilerde. Pb alımı, p-cV-ChMTII GFP'nin tütün bitkisine aktarılmasıyla iyileştirildi; ancak, Pb fitoremediasyonunda yeterli değildi. 

scholarly journals Physiologic Specialization in Drechslera Teres

1969 ◽  
Vol 22 (5) ◽  
pp. 1229 ◽  
Author(s):  
TN Khan ◽  
WJR Boyd
Keyword(s):  
Western Australia ◽  
Physiologic Specialization ◽  
Drechslera Teres ◽  
Physiologic Races

The occurrence of physiologic specialization in D. tere8 is reported. Three distinct physiologic races could be differentiated on two barley varieties, Algerian (C.l. 1179) and C.l. 7584. The distribution of these physiologic races in Western Australia is shown.

PHYSIOLOGIC SPECIALIZATION OF OAT STEM RUST IN CANADA

1944 ◽  
Vol 22c (5) ◽  
pp. 201-216 ◽  
Author(s):  
Margaret Newton ◽  
T. Johnson
Keyword(s):  
Stem Rust ◽  
Wide Distribution ◽  
Puccinia Graminis ◽  
Characteristic Type ◽  
Influence Of Temperature ◽  
Physiologic Specialization ◽  
Influence Of Temperature On ◽  
Physiologic Races

An account is given of the results of studies on the physiologic specialization of Puccinia graminis Avenae Erikss. and Henn. in Canada since the inception of the work. Twelve physiologic races were identified from 2586 isolates studied during the period 1921 to 1943. The annual surveys of the prevalence of physiologic races during this period show that each year races 1, 2, and 5 have comprised the bulk of the oat stem rust in all parts of Canada. The predominance of these races has been greatest in the three Prairie Provinces, where barberry is virtually non-existent. In regions where barberry is present, other races of greater range of pathogenicity have been found more frequently than in these three provinces. The occurrence of such races, however, was sporadic until 1943, in which year races 8, 10, and 11 attained a wide distribution, apparently traceable to wind-borne urediospores from the south. There is evidence that the strains of these races present in 1943 remain in the uredial stage for much longer periods than do strains of the same races collected in previous years—a fact that may have favoured their spread in this year.The role of barberry in the origination of generally virulent physiologic races is discussed. The possibility that such races may also originate by mutation is suggested by spontaneous pathogenic changes that occurred, in the greenhouse, in a culture of race 3 that gave rise to several cultures of race 7.The effect of environment on the identification of physiologic races is demonstrated by the seasonal influences on the reaction of the variety Sevnothree to races 1 and 11. On this variety the characteristic type 1 is frequently replaced, in summer, by type x.Experiments on the influence of temperature on the reaction of adult oat plants to stem rust showed that a constant temperature of about 80° F. does not appreciably affect the reaction of White Tartar and Richland, or of other varieties with the same type of resistance, but is capable of breaking down the resistance of certain varieties derived from the crosses Hajira × Joanette, Hajira × Banner, and Victoria × (Hajira × Banner).

THE EFFECT OF CROSS-GRAFTING BETWEEN IMMUNE, TOLERANT AND SUSCEPTIBLE NICOTIANA TABACUM CULTIVARS ON INFECTION WITH THIELAVIOPSIS ROOT ROT

1979 ◽  
Vol 59 (4) ◽  
pp. 1181-1183
Author(s):  
S. K. GAYED
Keyword(s):  
Nicotiana Tabacum ◽  
Root Rot ◽  
Necrotic Lesion ◽  
Thielaviopsis Basicola ◽  
Subsequent Growth ◽  
Lesion Formation ◽  
Breeding Lines ◽  
Immune Tolerant

The severity of infection of tobacco cultivars and breeding lines to necrotic lesion formation by Thielaviopsis basicola and subsequent growth of the plants of cross-grafted, self-grafted and ungrafted seedlings of the immune breeding lines 72C18, the tolerant cultivar Virginia 115 and the susceptible cultivars White Mammoth depended totally on the root irrespective of the grafted shoot.

Influence of double-stranded RNAs on growth, sporulation, pathogenicity, and survival of Chalara elegans

1995 ◽  
Vol 73 (7) ◽  
pp. 1001-1009 ◽  
Author(s):  
Zamir K. Punja
Keyword(s):  
Plant Pathogen ◽  
Dry Weight ◽  
Complete Loss ◽  
Thielaviopsis Basicola ◽  
Wild Type ◽  
C Elegans ◽  
Chalara Elegans ◽  
In The Wild ◽  
Rna Fragments ◽  
Type Strains

Three strains of Chalara elegans from diverse geographical areas that contained multiple (4 or 5) double-stranded RNA fragments were compared with spontaneously derived cultures from these strains that were either partially cured or completely free of dsRNA. In the wild-type strains, presence of the dsRNAs was found to significantly enhance phialospore production and pigmentation of colonies, whereas radial growth and mycelial dry weight accumulation were reduced. The rate and overall percentage of phialospore germination on 1% Noble water agar were also significantly reduced by the presence of the dsRNAs. In two partially cured strains (only one 2.8-kb fragment remaining), pathogenicity to various plant tissues was significantly enhanced when compared with the wild-type strains containing multiple dsRNA. However, survival in field soil was enhanced in one strain and reduced in the other. In the completely cured strain, the loss of multiple dsRNA fragments was associated with enhanced growth, reduced phialospore production, and a complete loss of pathogenicity and capability for survival in soil. These results indicate that the effects of dsRNAs in C. elegans vary with the strain. In general, the presence of multiple dsRNAs in this fungus enhanced sporulation, altered colony morphology, and reduced growth and pathogenicity. However, since the complete loss of dsRNA was found to eliminate pathogenicity and reduce survival, it suggests that some dsRNA fragments in C. elegans may confer an advantage to this soil-borne facultative plant pathogen. Key words: black root rot, soil-borne plant pathogen, Thielaviopsis basicola.

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