Resistance to Phytophthora cinnamomi in callus tissue derived from three avocado cultivars

1991 ◽  
Vol 69 (9) ◽  
pp. 2026-2032 ◽  
Author(s):  
D. Phillips ◽  
G. Weste ◽  
J. M. Hinch
Keyword(s):  
Key Words ◽  
Mycelial Growth ◽  
Callus Tissue ◽  
Phytophthora Cinnamomi ◽  
Host Tissue ◽  
Plant Parts ◽  
Whole Plant ◽  
Moderately Resistant ◽  
Undifferentiated Callus

Calli induced from various plant parts of avocado cultivars Topa Topa (susceptible), Duke 7 (moderately resistant), and Martin Grande (resistant) were inoculated with the root and collar rotting pathogen Phytophthora cinnamomi and examined for expression of resistance. Resistance was assessed quantitatively by measuring the rate of hyphal extension across the callus surface from the point of inoculation. Resistance in the callus tissue was associated with sparse, limited mycelial growth, in contrast to prolific, dense growth on and within susceptible callus. Rates of hyphal extension on calli of the resistant ‘Duke 7’ and ‘Martin Grande’ ranged from 1–3 mm day−1 compared with 4–7 mm day−1 on calli of ‘Topa Topa’. This difference in growth was significant (P = 0.05). This is the first report of avocado callus exhibiting resistance to P. cinnamomi and it mirrors that recorded for the whole plant for the three avocado cultivars tested. Thus, the level of resistance expressed by each cultivar appears to be innate whether the host tissue remains in an organized state or is in the form of an undifferentiated callus mass. The basis of the resistance expressed appeared to be largely physiological and (or) biochemical rather than anatomical. Assessing rates of hyphal colonization on undifferentiated callus masses in vitro may provide a new and useful assay for screening and selecting host lines in avocado resistant to P. cinnamomi. Key words: callus, avocado, in vitro, resistance, Phytophthora cinnamomi, Persea.

scholarly journals Inhibitory effect of the glucosinolate–myrosinase system on Phytophthora cinnamomi and Pythium spiculum

2019 ◽  
Vol 55 (No. 2) ◽  
pp. 93-101 ◽  
Author(s):  
Francisco Teodoro Arroyo Cordero ◽  
Rocío Rodríguez-Arcos ◽  
Ana Jiménez-Araujo ◽  
Rafael Guillén-Bejarano ◽  
María José Basallote ◽  
...  
Keyword(s):  
Mycelial Growth ◽  
High Performance ◽  
Phytophthora Cinnamomi ◽  
Inhibitory Effect ◽  
Reversed Phase ◽  
Field Application ◽  
Additional Information ◽  
Array Detection ◽  
Important Additional Information

Glucosinolate extracts from sprouts of common Brassica nigra, B. juncea cv. Scala, B. carinata cv. Eleven, and Sinapis alba cv. Ludique were analysed by reversed phase high-performance liquid chromatography-diode array detection-mass spectrometry. The effect of the glucosinolate–myrosinase system on in vitro mycelial growth of Phytophthora cinnamomi Rands and Pythium spiculum B. Paul was assessed. Likewise, sinigrin and sinalbin monohydrate commercial standards were also tested. The extracts from B. carinata, which contained 159 mmol/g plant DW equivalent (85% sinigrin, 5% gluconapin, and 3% glucotropaeolin), were the most effective against Phytophthora and Pythium isolates used in this study. However, the extract from S. alba, which contained 1 180 mmol/g (100% sinalbin), did not inhibit the mycelial growth of the isolates tested. The use of the glucosinolate-myrosinase system provides important additional information to advance in the implementation of field application of brassicaceous amendments for the control of soil-borne pathogens.

Effect of Dicamba on RNA and Protein

Weed Science ◽  
1971 ◽  
Vol 19 (3) ◽  
pp. 301-305 ◽  
Author(s):  
W. E. Arnold ◽  
John D. Nalewaja
Keyword(s):  
Callus Tissue ◽  
Growth Stages ◽  
Wheat Growth ◽  
Wild Buckwheat ◽  
Plant Parts ◽  
Temperature And Precipitation ◽  
Boot Stage ◽  
Polygonum Convolvulus ◽  
Anisic Acid

The effect of 3,6-dichloro-o-anisic acid (dicamba) was studied on wild buckwheat (Polygonum convolvulusL.) and wheat (Triticum aestivumL.) at two growth stages. Wild buckwheat, treated when 5 to 8 cm tall, was very susceptible to dicamba which caused rapid dehydration of the leaves and growth of callus tissue at stem internodes. Wild buckwheat, treated when flowering, increased in growth 2 days after treatment and then decreased after 4 days. Wheat growth tended to increase in all plant parts after treatment with dicamba at both the 2 to 3-leaf and the boot stages. Dicamba increased the RNA and protein content in wild buckwheat at both growth stages and in wheat at the boot stage. Dicamba affected the transition temperature and precipitation of reconstituted nucleohistone but not the uncombined nucleic acid or histonein vitro, indicating that a DNA-histone-dicamba complex had occurred. The binding of dicamba to protein varied with different proteins and reduced the UV absorbance of the bound proteins.

Phytotoxicity of 2,4-D and 2,4-Dichlorophenol to Red Clover (Trifolium pratense)

Weed Science ◽  
1989 ◽  
Vol 37 (6) ◽  
pp. 825-829 ◽  
Author(s):  
S. G. Taylor ◽  
D. G. Shilling ◽  
K. H. Quesenberry ◽  
G. R. Chaudhry
Keyword(s):  
Trifolium Pratense ◽  
Callus Tissue ◽  
Red Clover ◽  
Dry Weight ◽  
Shoot Dry Weight ◽  
Whole Plant ◽  
The Difference ◽  
Plant Level

Whole plant and tissue culture experiments were conducted to determine the difference in phytotoxicity of 2,4-D and its metabolite, 2,4-DCP, to red clover. At the whole plant level, the mean concentration of 2,4-DCP (10 mM) required to cause 50% growth inhibition (I50) of shoot dry weight was 24 times greater than for 2,4-D (0.42 mM). Using callus tissue, the I50value for 2,4-DCP (0.28 mM) was 22 times greater than for 2,4-D (0.013 mM) based on dry weights. The callus tissue was 36 and 32 times more sensitive to 2,4-DCP and 2,4-D than shoot tissue based on dry weights, respectively. These data indicate that 2,4-DCP was less phytotoxic than 2,4-D to red clover both in vitro and in vivo.

In vitro evaluation of antimicrobial peptides against Fusarium species

2009 ◽  
Vol 89 (4) ◽  
pp. 739-743 ◽  
Author(s):  
A Badea ◽  
F Eudes ◽  
R Graf ◽  
A Laroche ◽  
A E Berg ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Fusarium Head Blight ◽  
Key Words ◽  
Mycelial Growth ◽  
Fusarium Species ◽  
Common Species ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Head Blight

The in vitro activity of five antimicrobial peptides was evaluated against several Fusarium species that affect wheat in Canada. Among the peptides tested (10R, 11R, BMAP-18, MsrA2 and MsrA3) 10R was most effective against conidial germination, whereas MsrA2 showed activity against mycelial growth. Antimicrobial peptides 10R and MsrA2 were identified as potential candidates for engineering resistance against common species causing fusarium head blight in wheat. Key words: Antimicrobial peptides, fusarium head blight, conidia, mycelia

scholarly journals Benomyl Sensitivity of Isolates of Colletotrichum acutatum and C. gloeosporioides from Citrus

Plant Disease ◽  
2004 ◽  
Vol 88 (2) ◽  
pp. 125-130 ◽  
Author(s):  
N. A. R. Peres ◽  
N. L. Souza ◽  
T. L. Peever ◽  
L. W. Timmer
Keyword(s):  
Mycelial Growth ◽  
Colletotrichum Acutatum ◽  
Nucleotide Substitutions ◽  
Partial Sequencing ◽  
Research Fields ◽  
Fruit Drop ◽  
Highly Sensitive ◽  
Sensitive Isolate ◽  
Moderately Resistant

Postbloom fruit drop (PFD) of citrus, caused by Colletotrichum acutatum, produces orange-brown lesions on petals and results in premature fruit drop and the retention of calyces. C. gloeosporioides is common in groves and causes postharvest anthracnose on fruit. Both diseases are controlled effectively by the fungicide benomyl in research fields and commercial orchards. Highly sensitive and resistant isolates of C. gloeosporioides were found, whereas all isolates of C. acutatum tested were moderately resistant. In preliminary studies conducted in vitro with three isolates of each, mycelial growth of sensitive isolates of C. gloeosporioides was inhibited completely by benomyl (Benlate 50 WP) at 1.0 μg/ml, whereas resistant isolates grew well at 10 μg/ml. Growth of all isolates of C. acutatum was inhibited by about 55% at 0.1 μg/ml and by 80% at 1.0 μg/ml. Spore germination of C. acutatum was inhibited more at 0.1 μg/ml than at 1.0 μg/ml or higher concentrations. In all, 20 isolates of C. acutatum from 17 groves and 20 isolates of C. gloeosporioides from 7 groves were collected from locations with different histories of benomyl usage in São Paulo, Brazil, and Florida, United States. Benomyl at 1.0 μg/ml completely inhibited growth of 133 isolates of C. gloeosporioides, with the exception of 7 isolates that were highly resistant to the fungicide, whereas all isolates of C. acutatum were only partially inhibited at 0.1 and 1.0 μg/ml. Analysis of variance indicated that the sensitivity of the isolates of C. acutatum was not affected by benomyl usage or grove of origin, and country of origin had only minor effects. No highly resistant or sensitive isolate of C. acutatum was recovered. Partial sequencing of the β-tubulin gene did not reveal nucleotide substitutions in codons 198 or 200 in C. acutatum that usually are associated with benomyl resistance in other fungi.

scholarly journals Silver Nanoparticles and Polyphenol Inclusion Compounds Composites for Phytophthora cinnamomi Mycelial Growth Inhibition

Antibiotics ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 76 ◽  
Author(s):  
Petruta Matei ◽  
Jesús Martín-Gil ◽  
Beatrice Michaela Iacomi ◽  
Eduardo Pérez-Lebeña ◽  
María Barrio-Arredondo ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Growth Inhibition ◽  
Inclusion Compounds ◽  
Mycelial Growth ◽  
Water Solubility ◽  
Phytophthora Cinnamomi ◽  
Deep Eutectic Solvent ◽  
Phase System ◽  
Two Phase

Phytophthora cinnamomi, responsible for “root rot” or “dieback” plant disease, causes a significant amount of economic and environmental impact. In this work, the fungicide action of nanocomposites based on silver nanoparticles and polyphenol inclusion compounds, which feature enhanced bioavailability and water solubility, was assayed for the control of this soil-borne water mold. Inclusion compounds were prepared by an aqueous two-phase system separation method through extraction, either in an hydroalcoholic solution with chitosan oligomers (COS) or in a choline chloride:urea:glycerol deep eutectic solvent (DES). The new inclusion compounds were synthesized from stevioside and various polyphenols (gallic acid, silymarin, ferulic acid and curcumin), in a [6:1] ratio in the COS medium and in a [3:1] ratio in the DES medium, respectively. Their in vitro response against Phytophthora cinnamomi isolate MYC43 (at concentrations of 125, 250 and 500 µg·mL−1) was tested, which found a significant mycelial growth inhibition, particularly high for the composites prepared using DES. Therefore, these nanocomposites hold promise as an alternative to fosetyl-Al and metalaxyl conventional systemic fungicides.

scholarly journals Thiophanate-Methyl Resistance and Fitness Components of Colletotrichum musae Isolates from Banana in Brazil

Plant Disease ◽  
2017 ◽  
Vol 101 (9) ◽  
pp. 1659-1665 ◽  
Author(s):  
Willie Anderson dos Santos Vieira ◽  
Waléria Guerreiro Lima ◽  
Eduardo Souza Nascimento ◽  
Sami Jorge Michereff ◽  
Ailton Reis ◽  
...  
Keyword(s):  
Fungicide Resistance ◽  
Mycelial Growth ◽  
Postharvest Disease ◽  
Banana Fruit ◽  
Coding Region ◽  
Banana Production ◽  
Thiophanate Methyl ◽  
Moderately Resistant ◽  
Colletotrichum Musae

Anthracnose, caused by Colletotrichum musae, is the most important postharvest disease of banana and is widely distributed among the banana production regions in Brazil. Although thiophanate-methyl is a fungicide frequently used in Brazilian banana orchards to control Sigatoka leaf spot, Collettotrichum populations are also exposed, resulting in the evolution of fungicide resistance and the inability to manage banana anthracnose. We investigated 139 Brazilian isolates of C. musae for thiophanate-methyl sensitivity in vitro. The 50% mycelial growth inhibition (EC50) values varied between 0.003 and 48.73 μg/ml. One-hundred and thirty isolates were classified as sensitive, with EC50 values ranging from 0.003 to 4.84 μg/ml, while the remaining nine isolates were considered moderately resistant, with EC50 values ranging between 10.43 and 48.73 μg/ml. Resistant or highly resistant isolates (EC50 > 100 μg/ml) were not found. A substitution of TAC for TTC at codon 200 in a coding region of the β-tubulin gene was associated with the moderately resistant phenotype. Applications of thiophanate-methyl formulation to detached banana fruit at the label rate (500 μg/ml) showed low efficacy in controlling the moderately resistant isolates on banana fruits. However, there is no indication of a reduction in fitness associated with fungicide resistance as sensitive and moderately resistant isolates do not differ with respect to mycelial growth rate (P = 0.098), spore production (P = 0.066), spore germination (P = 0.366), osmotic sensitivity (P = 0.051), and virulence (P = 0.057). Our results revealed absence of adaptability cost for the moderately resistant isolates, suggesting that they can be dominant in population if the fungicide continue to be applied.

A Review of the Place of in vitro Cell Culture Systems in Studies of Action, Metabolism and Resistance of Biocides Affecting Photosynthesis

1979 ◽  
Vol 34 (11) ◽  
pp. 905-913 ◽  
Author(s):  
Jonathan Gressel
Keyword(s):  
Cell Culture ◽  
Genetic Resistance ◽  
Homogeneous State ◽  
Higher Plant ◽  
Crop Species ◽  
Culture Systems ◽  
Plant Parts ◽  
Whole Plant ◽  
Plant Densities

Abstract The homogeneity, density and axenic nature of cell culture system s have made them an amenable tool for studying many aspects of biocide research; screening, metabolism , m ode of action and resistance. Cell cultures are “multi-homogeneous” and each homogeneous state may be analogous to different plant parts. Cultures can be homogeneously green, homogeneously white in either a homogeneously exponential or stationary phase of growth. Examples are be presented showing why no single homogeneous state should be envisaged to be analogous to a whole plant in biocide studies. Because of the possibility of more uniform herbicide application, culture systems have a use in isolatin g resistant crop strains, at higher selection pressures and much higher “plant” densities than is possible in the field, with recent successes. Protoplast fusion techniques may allow the transfer of genetic resistance between related but genetically incompatible crop species.

A COMPARISON OF IN VITRO AND IN VIVO DRY MATTER DIGESTTBDLITY TECHNIQUES FOR THE EVALUATION OF FORAGE QUALITY

1987 ◽  
Vol 67 (2) ◽  
pp. 573-576 ◽  
Author(s):  
E. V. VALDES ◽  
G. E. JONES
Keyword(s):  
Key Words ◽  
Dry Matter ◽  
Forage Quality ◽  
In Vitro Digestibility ◽  
Two Stage ◽  
Dry Matter Digestibility ◽  
Whole Plant ◽  
Standard Deviations

A two-stage cellulase-pepsin technique (CS) was compared with the two-stage rumen inoculum-pepsin (IVDMD) method to predict in vivo dry matter digestibility (in vivo DMD) in grasses (n = 30) and legumes (n = 25). Comparisons of CS with IVDMD in whole-plant corn (n = 186) were also conducted. There were significant correlations (P < 0.01) between CS and in vivo DMD and between CS and IVDMD in all forages. The coefficients of determination (r2) and residual standard deviations for the prediction of IVDMD by CS varied between 0.76 and 0.90 and 2.5 and 3.4, respectively. Key words: Digestibility (in vitro), digestibility (in vivo), fungal cellulases, forage

scholarly journals Forage potential and silage quality of four varieties of saccharine sorghum

2015 ◽  
Vol 50 (12) ◽  
pp. 1201-1207 ◽  
Author(s):  
Marco Antonio Previdelli Orrico Junior ◽  
Marciana Retore ◽  
Débora Maurício Manarelli ◽  
Fernanda Barboza de Souza ◽  
Luana Liz Medina Ledesma ◽  
...  
Keyword(s):  
Nutritional Quality ◽  
Nutritional Value ◽  
Plant Production ◽  
In Vitro Digestibility ◽  
Plant Parts ◽  
Whole Plant ◽  
Morphological Composition ◽  
Fermentation Quality

Abstract: The objective of this work was to evaluate four cultivars of saccharine sorghum (Sorghum bicolor) regarding productivity, chemical composition of plant parts, and quality of the ensiling process. The tested varieties of saccharine sorghum were BRS 506, BRS 508, BRS 509, and BRS 511. The experiment was divided into two trials, which assessed: production, morphological composition, and nutritional quality of the saccharine varieties; and fermentation quality and nutritional value of the silage produced from the saccharine varieties. Of the tested varieties, BRS 509 and BRS 511 showed the highest total dry matter (DM) production. The BRS 508 variety presented the highest in vitro digestibility of the whole plant (70.65% DM). During ensiling, the BRS 509 variety showed the lowest DM loss (8.87%). The highest effluent production was observed for BRS 506 and BRS 508, with yields of 521.87 and 393.16 kg Mg-1 ensiled DM, respectively. The BRS 511 variety is the most recommended because of the best results for plant production and nutritional quality. Regarding the ensiling process, BRS 509 presents the lowest fermentation losses and the highest nutritional value of silage.

Sign in / Sign up

Export Citation Format

Share Document