Photosensitivity of Puccinia graminis f.sp. tritici urediniospores in vitro and on the leaf surface

1980 ◽  
Vol 74 (3) ◽  
pp. 543-549 ◽  
Author(s):  
I.K. Knights ◽  
J.A. Lucas
Keyword(s):  
Leaf Surface ◽  
Puccinia Graminis

scholarly journals Antagonism of Bacillus thuringiensis to phytopathogenic micromicetes as pathogens of apple trees

2021 ◽  
Author(s):  
О. Sherstoboeva ◽  
А. Krzyhanivsky ◽  
А. Bunas
Keyword(s):  
Bacillus Thuringiensis ◽  
Nutrient Medium ◽  
Leaf Surface ◽  
Water Soluble ◽  
Ecological Niches ◽  
Negative Consequences ◽  
Apple Trees ◽  
Produce Water ◽  
Antagonistic Microorganisms

Antagonistic microorganisms, producing bactericidal and fungicidal substances, spread in space and occupy various ecological niches. Antagonistic action of microorganisms can be combined with a number of other properties that can be used by humans for their own purposes. Microorganisms — agents of biological products often have a multifunctional effect on the components of the agroecosystem, which under the influence of various environmental factors could have positive and negative consequences. The aim of the study was to study the effect of new highly active entomopathogenic strains of Bacillus thuringiensis on non-target objects — components of the biocenosis of the apple orchard. When developing technologies for biocontrol of the number of apple trees pests using B. thuringiensis revealed an additional positive protective effect — reducing the number of pathogens of fungal diseases on the leaf surface. Treatment of apple leaves with a liquid culture of strain B. thuringiensis 0376 after 72 hours of application reduced the number of scab of Fusicladium dendriticum by 7 times, and the pathogen of monolisis of Monilia fructigena — 9 times. Strain B. thuringiensis 0371 showed the highest level of antagonism, because in vitro completely inhibited the growth and development of micromycetes on the surface of the nutrient medium. On the leaf surface, the application of culture strain 0371 reduced the number of Fusicladium dendriticum by 92%, and Monilia fructigena — by 86% after 72 hours of treatment. In a field experiment when treating apple trees with a culture of this strain, scab development decreased by 7.1%. Strain B. thuringiensis 787 did not show antagonism against phytopathogenicmicromycetes during co-cultivation on nutrient medium, which may be explained by its inability to produce water-soluble exotoxin, in contrast to strains of B. thuringiensis, which are antagonists of scab and apple monolisis. Strain B. thuringiensis 0371 requires further research and development of its formulations, because it is promising for the creation of a complex biological product with insect-fungicidal properties for use in ecological and agriculture friendly technologies.

In vitro growth of wheat and flax rust fungi on complex and chemically defined media

1974 ◽  
Vol 52 (6) ◽  
pp. 1183-1195 ◽  
Author(s):  
A. Bose ◽  
Michael Shaw
Keyword(s):  
Liquid Medium ◽  
Aspartic Acid ◽  
Yeast Extract ◽  
Australian Isolate ◽  
Puccinia Graminis ◽  
Good Growth ◽  
Complex Media ◽  
Mineral Salts ◽  
Melampsora Lini

Growth from uredospores seeded in axenic culture is described for several races of Puccinia graminis Pers. f. sp. tritici (Erikss. and Henn.) and race 3 of Melampsora lini (Ehrenb.) Lév. on complex media containing peptone, yeast extract, and bovine serum albumin (BSA); and for an Australian isolate of Puccinia graminis, race 126-ANZ 6,7, and Melampsora lini, race 3, on chemically defined, liquid media.Of six North American isolates of Puccinia graminis only race 38 formed colonies approaching those of race 126-ANZ 6,7 in final size and general morphology on complex media. 5′AMP had no effect on the growth of 126-ANZ 6,7, but cyclic AMP inhibited growth after uredospore germination. Good growth and sporulation were obtained with 126-ANZ 6,7, but not with the other isolates tested, using a new, chemically defined liquid medium, sterilized by millipore filtration, and containing glucose, Czapek's minerals plus micronutrients, Ca2+, glucose and aspartic acid, glutathione, and cysteine. Uredospores produced in culture reinfected exposed mesophyll tissue, but not intact seedling leaves of wheat.Highly reproducible growth and sporulation of Melampsora lini, race 3, were obtained routinely on a solid medium containing Difco-Bacto agar, sucrose, Knop's minerals, micronutrients, yeast extract, peptone, and BSA. Vegetative cultures, capable of reinfecting the cut ends of surface-sterilized flax cotyledons, could be maintained indefinitely by subdivision before sporulation and transfer to the same medium minus BSA. Evidence is presented that BSA stimulated the development of colonies and the formation of uredospores. The mode of action of BSA is unknown, but it could not be replaced by putrescine.A new chemically defined, liquid medium containing sucrose, Knop's mineral salts, micronutrients, aspartic (or glutamic) acid, and cysteine supported the growth of colonies of Melampsora lini in a highly reproducible manner. The formation of uredospores and teliospores by these colonies was controlled by (a) the level of Ca2+ (as Ca(NO3)2∙4H2O), (b) the concentration of aspartic acid, and (c) the number of colonies per flask. At inoculum levels giving 40 to 60 colonies per flask, in media containing 8.5 mM Ca+ and 45 mM aspartic acid, uredospore formation occurred in 60 to 70% of the colonies. A decrease in the Ca2+ level to 4.25 mM, or a decrease in aspartic acid to 22.5 mM, or adjustment of the inoculum level to give about 10 colonies per flask each resulted in only infrequent sporulation. The uredospores produced in vitro infected intact, 1-week-old flax cotyledons in a normal manner.

Light-dependent morphogenesis of conidia of Trichometasphaeria turcica in vitro

1976 ◽  
Vol 54 (7) ◽  
pp. 552-555 ◽  
Author(s):  
W. G. Benedict
Keyword(s):  
White Light ◽  
Incident Energy ◽  
Sweet Corn ◽  
Leaf Surface ◽  
Green Light ◽  
Conidial Production ◽  
Helminthosporium Turcicum ◽  
Induced Changes

Induced changes in morphogenesis of developing and germinating conidia of Trichometasphaeria turcica Luttrell (Helminthosporium turcicum Passerini) exposed to various intensities and wavelengths of light were studied. A method to evaluate production of conidia on irradiated mycelium is described. Conidial production and germination were directly correlated with the quantity and quality of incident energy utilized. In white light highest conidial production occurred at an intensity of 23 000 ergs/cm2 s. Green light (515 nm) significantly further enhanced conidial production. Primary hyphae of conidia exposed to green light produced appressoria when germinated in white light. Hyphae of conidia exposed to orange light (640 nm) were branched or curled without appressoria. Only sensitivity to incident energy could account for the behaviour of T. turcica in vitro and by inference account for the pathogenic adaptation of this fungus in the reflected green light of the sweet-corn leaf surface.

Development of the stomatal complex and leaf surface of Agave angustifolia Haw. ‘Bacanora’ plantlets during the in vitro to ex vitro transition process

2015 ◽  
Vol 189 ◽  
pp. 32-40 ◽  
Author(s):  
Kelly M. Monja-Mio ◽  
Felipe Barredo Pool ◽  
Gastón Herrera Herrera ◽  
Martín EsquedaValle ◽  
Manuel L. Robert
Keyword(s):  
Leaf Surface ◽  
Transition Process ◽  
Ex Vitro ◽  
Stomatal Complex ◽  
Agave Angustifolia

scholarly journals Effect of irradiation on the growth and rooting of a climbing rose in vitro

2021 ◽  
Vol 935 (1) ◽  
pp. 012007
Author(s):  
N Kondrateva ◽  
R Bolshin ◽  
M Krasnolutskaya ◽  
A Baturin ◽  
K Baturina ◽  
...  
Keyword(s):  
Surface Area ◽  
Leaf Surface ◽  
Air Humidity ◽  
Average Growth ◽  
Continuous Irradiation ◽  
Pulsed Mode ◽  
Relative Air Humidity ◽  
Leaf Surface Area ◽  
Reproduction Factor

Abstract The article presents the influence of pulsed and continuous irradiation (400…780 nm) on in vitro growth of the climbing rose variety “Camelot” at the illumination of 80±5 mmol/(m2s), temperature - 24±10C, and the relative air humidity - 73±2%. It was found that the experimental led light (LED) pulsed phytoirradiator contributed to a significant increase in the leaf surface area during cultivation of climbing rose microstems in Gamborg’s nutrient medium, the average growth was 2.94 mm2 compared to 2.80 mm2 in the control. Pulse irradiation increases the reproducibility of climbing roses by 1.7 times, and also increases the rooting rate up to 96% compared to 82% in the control. Experimental LED phytoirradiator of continuous irradiation promoted an increase in the leaf surface area growth at the level of the control luminescent phytoirradiator, but also provided a significant increase in the reproduction factor and rooting rate of rose microstems. In the pulsed mode, phytoinstallations consume only 50% of the electricity compared to the continuous irradiation mode.

scholarly journals Natural colonization of leaves of 'Pêra' sweet orange and related varieties by Guignardia citricarpa

2002 ◽  
Vol 27 (5) ◽  
pp. 479-483 ◽  
Author(s):  
EVANDRO H. SCHINOR ◽  
FRANCISCO A. A. MOURÃO FILHO ◽  
CARLOS I. AGUILAR-VILDOSO ◽  
JOAQUIM TEÓFILO SOBRINHO
Keyword(s):  
Leaf Surface ◽  
Sweet Orange ◽  
Agar Medium ◽  
Drying Process ◽  
In Vitro Production ◽  
Guignardia Citricarpa ◽  
Reproductive Structures ◽  
Colonization Density ◽  
Vitro Production

The purpose of this research was to evaluate the differences in the colonization and production of structures in the leaves of 'Pêra' sweet orange (Citrus sinensis) clones and related varieties by Guignardia citricarpa. The natural colonization and the production of reproductive structures in the leaves and in vitro of ten 'Pêra' sweet orange was quantified in the following clones: Bianchi, Dibbern C.V., EEL, IAC 2000, Olímpia 15161, Premunizada 1212, Premunizada 1743/82, R. Gullo 1569/244, R. Gullo 1570/246 and Vimusa; and in five related varieties: Redonda C.N, Ovale 968, Ovale San Lio 969, Lamb Summer and Corsa Tardia. The quantification of the colonization density of G. citricarpa in the leaves was obtained through isolation. Incidence and colonization density (cm²) were calculated for each clone. The production of reproductive structures was accomplished through the moistening and drying process of the leaves. The incidence (percentage of affected leaves) and the leaf surface percentage occupied by the reproductive fungus structures were quantified. The in vitro production of reproductive structures was accomplished in water-agar medium. The number of immature and total reproductive fungus structures (cm²), and the percentage of picnidia with liberation of spores were quantified. Significant differences were not observed among clones related to the colonization of the leaves. But there were differences in the induction experiments, i.e., in the leaf surface percentage occupied by the reproductive fungus structures and the in vitro production of reprodutive fungus structures.

Alterations in 1,4-Benzoxazinone Levels Following Inoculation with Stem Rust in Wheat Leaves Carrying Various Alleles for Resistance and Their Possible Role as Phytoalexins in Moderately Resistant Leaves

1990 ◽  
Vol 45 (11-12) ◽  
pp. 1151-1155 ◽  
Author(s):  
Claudia Bücker ◽  
Hans J. Grambow
Keyword(s):  
Triticum Aestivum ◽  
Stem Rust ◽  
Triticum Aestivum L ◽  
Puccinia Graminis ◽  
Conversion Product ◽  
Near Isogenic Lines ◽  
Wheat Leaves ◽  
Infection Types ◽  
Moderately Resistant

The contents of 1,4-benzoxazinone derivatives in wheat plants infected with Puccinia graminis Pers. f. sp. tritici Ericss. & Henn, race 32, and in uninfected controls were examined in four near-isogenic lines of different infection types: Triticum aestivum L., cultivar Prelude Sr5 (highly resistant), Sr24, Sr26 (moderately resistant), and srx (susceptible). In all infection types the contents of DIMBOA -glc and HMBOA -glc decrease with time in the uninfected controls as well as in the infected plants. However, following inoculation, the synthesis of HDIBOA -glc is drastically increased in the moderately resistant cultivars. The results suggest that this fully methylated 1,4-benzoxazinone may function as a phytoalexin in this type of interaction. The benzoxazolinone MBOA which has been described as an in vitro conversion product of the benzoxazinones mentioned above is not detected in inoculated or uninoculated leaves.

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