scholarly journals Antifungal Nanoformulation for Biocontrol of Tomato Root and Crown Rot Caused by Fusarium oxysporum f. sp. radicis-lycopersici

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1132
Author(s):  
Ricardo Aravena ◽  
Ximena Besoain ◽  
Natalia Riquelme ◽  
Aldo Salinas ◽  
Miryam Valenzuela ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Crown Rot ◽  
Vegetable Crop ◽  
Tomato Root ◽  
Preventive Control ◽  
Solanum Lycopersicum L ◽  
The World ◽  
Root And Crown Rot ◽  
In Vitro Effects

Tomatoes (Solanum lycopersicum L.) are the most cultivated and important vegetable crop in the world. These plants can wilt during crop growth due to fusarium wilt (fusariosis), a disease that damages tomato vascular systems. The Fusarium isolated and analyzed in this work correspond to Fusarium oxysporum f. sp. radicis-lycopersici. The isolates were molecularly identified, and analysis was done on the in vitro effects of the nanoemulsions (previously obtained from extracts of Chilean medicinal plants of the genera Psoralea and Escallonia) to inhibit mycelial and conidial germination of the isolates. Subsequently, the nanoemulsions were evaluated under greenhouse conditions for preventive control of fusariosis in the root and crown, with high levels of disease control observed using the highest concentrations of these nanoemulsions, at 250 and 500 ppm.

scholarly journals Root growth in tomato seedlings in response to bacterial inoculation Serratia sp.

2020 ◽  
Vol 9 (7) ◽  
pp. e89973634
Author(s):  
Ana Carla Pinheiro Lima ◽  
Leonardo Oliveira Medici ◽  
Débora Alves Gonzaga da Silva Ballesteiro Pereira ◽  
Eduardo de Assis Lima
Keyword(s):  
Root Growth ◽  
Water Movement ◽  
Growth Promotion ◽  
Water Restriction ◽  
Negative Effects ◽  
Tomato Root ◽  
Tomato Seedlings ◽  
Solanum Lycopersicum L ◽  
Different Doses

Growth-promoting rhizobacteria are soil bacteria that inhabit the surrounding root, and are directly or indirectly involved in promoting plant growth and development. The productivity efficiency of these groups of microorganisms can be applied to planting crops, providing an interesting alternative for minimize the negative effects of water deficit. The objective of this study was to verify if the mechanism of growth promotion of the bacterium is similar to that promoted by polyethylene glycol (PEG) and to compare the possible effects of water stress on the tomato against the effects of inoculation of the bacterium Serratia sp. The methodology was based on in vitro bioassays using tomato (Solanum lycopersicum L.) seedlings, kept in a growth chamber with temperature of 25 °C and photoperiod of 12 hours. The results revealed that the promotion of tomato root growth by Serratia sp. is similar to that promoted by PEG 7%, differing significantly from the results found with different doses of indoleacetic acid (IAA). The promotion of root growth in tomatoes by Serratia sp. and PEG 7% partly indicates a physical effect, since the water restriction imposed by the PEG molecule decreases the water movement capacity, also observed by bacteria, when colonizing plant tissues and cells (biofilm) reducing the hydraulic conductivity of water through the root. Stimulation to promote root growth in tomatoes cannot be reproduced by auxin.

scholarly journals Insensitivity to Metalaxyl Among Isolates of Phytophthora capsici Causing Root and Crown Rot of Pepper in Southern Italy

Plant Disease ◽  
1998 ◽  
Vol 82 (11) ◽  
pp. 1283-1283 ◽  
Author(s):  
A. M. Pennisi ◽  
G. E. Agosteo ◽  
S. O. Cacciola ◽  
A. Pane ◽  
R. Faedda
Keyword(s):  
Mating Type ◽  
Southern Italy ◽  
Phytophthora Capsici ◽  
Crown Rot ◽  
Metalaxyl Resistance ◽  
Local Selection ◽  
Capsicum Spp ◽  
Root And Crown Rot ◽  
Single Hypha

Pepper (Capsicum annuum L.) has become an economically important crop in the coastal provinces of Catanzaro and Vibo Valentia, in Calabria (southern Italy). An old local selection Riggitano, very susceptible to root and crown rot caused by Phytophthora capsici Leonian, is the prevalent cultivar in this area. Although repeated applications of metalaxyl are used as a soil drench, severe outbreaks occur each year on greenhouse crops. To examine metalaxyl resistance in P. capsici, 60 single-hypha isolates of P. capsici were tested in vitro for their level of sensitivity to metalaxyl. The isolates were collected from 1992 to 1997, during epidemic outbreaks of root and crown rot, from two commercial greenhouse pepper crops, near Vibo Valentia and Lametia Terme (Catanzaro). Fungicide sensitivity was determined by plating mycelial plugs onto potato dextrose agar (PDA) amended with metalaxyl. The fungicide was added to PDA after autoclaving, at final concentrations of 0.1, 1, 5, 10, 50, 100, and 200 μg/ml a.i. The percentage of inhibition of radial growth on metalaxyl-amended medium compared with the growth on unamended medium was determined after 6 days of incubation in the dark at 25°C. Three replicate petri dishes were used per treatment and each test was performed twice. The isolates were paired in culture on V8 agar with isolates of P. capsici of known mating type and all proved to be A2 mating type. Significant variation was observed among the isolates tested in responce to metalaxyl. The ED50 values for in vitro inhibition of mycelial growth by metalaxyl ranged from 1 to 11 μg/ml, whereas an ED 50 value of 0.1 μg/ml had been reported for a wild-type isolate of P. capsici obtained from pepper in northern Italy (3). The variation observed among the isolates from Calabria appeared unrelated to both the geographical origin and the year of isolation. The isolates from Calabria were inhibited by between 1 and 12% at 0.1 μg/ml and by between 7 and 27% at 1 μg/ml, proving to be less sensitive to metalaxyl than isolates from Capsicum spp. originating from Central America, tested by other authors (1). According to the criterion used in a recent screening for sensitivity to metalaxyl (2), 19% of the isolates from Calabria should be considered sensitive, as they were inhibited by more than 60% at 5 μg/ml, while all the others were intermediate, as they were inhibited less than 60% at 5 μg/ml but more than 60% at 100 μg/ml. On the basis of this preliminary screening, we report the presence of insensitivity to metalaxyl in field isolates of P. capsici in southern Italy. Although no isolate tested appeared highly resistant to metalaxyl, the presence of a high proportion of isolates with an intermediate level of resistance should be a reason for the growers to use metalaxyl more cautiously to control root and collar rot. References: (1) M. D. Coffey and L. A. Bower. Phytopathology 74:502, 1984. (2) G. Parra and J. Ristaino. Plant Dis. 82:711, 1998. (3) M. L. Romano and A. Garibaldi. La difesa delle piante 3:153, 1984.

scholarly journals Comparative variation of Phoma medicaginis Malbr. Roum. var. medicaginis Boerema for cultural characteristics and virulence to roots and crowns of alfalfa

1969 ◽  
Vol 89 (3-4) ◽  
pp. 229-242
Author(s):  
Rocío del P. Rodríguez
Keyword(s):  
Environmental Conditions ◽  
Geographic Location ◽  
Crown Rot ◽  
Cultural Characteristics ◽  
Greenhouse Experiments ◽  
Phoma Medicaginis ◽  
Sources Of Variation ◽  
Root And Crown Rot

The in vitro and in vivo variation of selected isolates of Phoma medicaginis var. medicaginis was studied in controlled environmental conditions. Isolates were relatively stable in morphology and pigmentation of the colony but varied more in final diameter of the colony, rate of growth and sporulation. The isolate, the organ and geographic location from which it was obtained were significant sources of variation. All isolates caused root and crown rot symptoms in growth chamber and greenhouse experiments. Differences in virulence among isolates were expressed in the length of root lesions. Plant dry weights were reduced by 82% in greenhouse trials. 

scholarly journals First Report of Fusarium oxysporum Causing Root and Crown Rot on Barbados Aloe in Greece

Plant Disease ◽  
2015 ◽  
Vol 99 (11) ◽  
pp. 1649-1649 ◽  
Author(s):  
D. J. Vakalounakis ◽  
N. Kavroulakis ◽  
K. Lamprou
Keyword(s):  
Fusarium Oxysporum ◽  
Crown Rot ◽  
First Report ◽  
Root And Crown Rot

scholarly journals Comparación de métodos de inoculación de Fusarium oxysporum f. sp. lycopersici (Sacc.) Snyder & Hansen, causante del marchitamiento vascular del tomate

2019 ◽  
Vol 43 (167) ◽  
pp. 227
Author(s):  
Luisa Fernanda Cardona-Piedrahita ◽  
Jairo Castaño-Zapata
Keyword(s):  
Fusarium Oxysporum ◽  
Solanum Lycopersicum ◽  
Solanum Lycopersicum L

El tomate (Solanum lycopersicum L.), la hortaliza de mayor importancia en Colombia y en el mundo, es atacada por numerosas enfermedades, entre ellas la marchitez vascular causada por Fusarium oxysporum f. sp. lycopersici. La enfermedad produce pérdidas entre el 21 y el 47 % en cultivos en exposición libre y bajo cubierta. El objetivo del presente trabajo fue comparar cuatro métodos de inoculación del hongo en plántulas de tomate Sweet Million obtenidas a partir de semilla, sembradas en turba canadiense estéril y medio Murashige &Skoog (MS) y conservadas en condiciones controladas en el Laboratorio de Tejidos Vasculares y del cuarto de termoterapia de la Universidad de Caldas donde se seleccionaron 25 plántulas por cada método de inoculación. Los tratamientos fueron: inyección en la corona de la raíz (T1), inmersión de las raíces (T2), disco de agar en la corona de la raíz (T3) e inoculación in vitro (T4). En la incidencia final de la enfermedad, así como las pruebascomparativas de Duncan, se registraron diferencias significativas (p≤0,001) entre los diferentes métodos de inoculación. La única metodología que produjo el 100 % de incidencia del marchitamiento vascular en un menor periodo de incubación fue la inoculación in vitro. La mayor tasa de desarrollo (r) del marchitamiento vascular se reportó con el método de inoculación in vitro con una tasa de r=0,92, seguido por los discos de agar, la inmersión y la inyección, siendo estas dos últimas las de menor tasa de desarrollo. El método de inoculación in vitro puede ser útil para la selección masiva de materiales de tomate promisorios contra la marchitez vascular. © 2019. Acad. Colomb. Cienc. Ex. Fis. Nat.

scholarly journals In vitro effects of plant extracts and fungicides to control wilt of brinjal (Solanum melongena L.)

2017 ◽  
Vol 26 (1) ◽  
pp. 39-44
Author(s):  
Md Ariful Islam ◽  
S Shamsi ◽  
S Hosen ◽  
MA Bashar
Keyword(s):  
Fusarium Oxysporum ◽  
Plant Extracts ◽  
Allium Sativum ◽  
Solanum Melongena ◽  
Effective Inhibitor ◽  
Poisoned Food Technique ◽  
In Vitro Effects

Five fungicides viz., Bavistin DF, Capvit 50 WP, Dithane M-45, Greengel 72 WP and Tilt 250 EC were selected to evaluate in vitro efficacy against Fusarium oxysporum and F. solani at 100, 200, 300, 400 and 500 ppm following poisoned food technique. Bavistin, Capvit and Tilt were found to be most effective inhibitor against the test pathogens isolated from brinjal wilt. Bavistin and Tilt completely inhibited the growth of F. oxysporum and F. solani at all the tested concentrations. Out of five plant extracts, Allium sativum identified as the promising botanical fungicide for testing against wilted plants of brinjal. The result of present study will be helpful in suggesting some effective plant extracts and fungicides for controlling wilting of brinjal. Dhaka Univ. J. Biol. Sci. 26(1): 39-44, 2017 (January)

scholarly journals First Report of Fusarium oxysporum f. sp. radicis-cucumerinum on Cucumber in Spain

Plant Disease ◽  
2001 ◽  
Vol 85 (11) ◽  
pp. 1206-1206 ◽  
Author(s):  
A. Moreno ◽  
A. Alférez ◽  
M. Avilés ◽  
F. Diánez ◽  
R. Blanco ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Crown Rot ◽  
F1 Hybrid ◽  
Potato Dextrose Broth ◽  
Disease Symptoms ◽  
First Report ◽  
Vascular Discoloration ◽  
Root And Crown Rot ◽  
Three Stages ◽  
Stem Lesions

During December 1999, root and stem rot was observed on greenhouse-grown cucumber (cvs. Albatros, Brunex, Acapulco, and Cerrucho) plants in Almería, Spain, using rock wool cultures. The disease caused severe damage, estimated at a loss of up to 75% of the plants, in the first greenhouse affected; afterward, the disease was found in eight additional greenhouses (14 ha) in 1999 and 2000. Stem lesions extended up to 10 to 12 cm above the crown in mature plants, although no fruit damage was observed. In the advanced stages, abundant development of orange sporodochia was evident on crown and stem lesions, without vascular discoloration. Root, crown, and stem pieces that were placed on potato dextrose agar (PDA) after surface-disinfection with 5% sodium hypochlorite, rinsed, and dried resulted in pure fungal colonies. Based on morphological characteristics of conidia, phialides, and chlamydospores from the isolations, the fungus was identified as Fusarium oxysporum Schlechtend.:Fr. Pathogenicity tests were conducted on cucumber (cvs. Marketmore 76 and Cerrucho [F1 hybrid]), melon (cvs. Amarillo oro, Perlita, Piboule, Tania, and Nipper [F1]), watermelon (cvs. Sugar Baby, Sweet Marvel, Jubilee, and Pata Negra and hybrid Crimson sweet), Cucurbita maxima × Cucurbita moschata, zucchini (cv. Senator), and loofah (Luffa aegyptiaca) at several stages: (i) pregermination; (ii) 1 or 2 true leaves; and (iii) more than 10 true leaves. Five fungal isolates were grown on PDA or shaken potato dextrose broth at 25°C for 8 days. Inoculation was performed in pots (10 seeds or plants of each cultivar or hybrid and isolate) by drenching with 100 ml of a fungal suspension (104 to 106 CFU/ml). Sterile water was applied to noninoculated control plants. Tests were repeated in growth chambers at 25°C (night) and 28°C (day) with a 16-h photoperiod. Fifteen to fifty days after inoculation, cucumber and melon plants at all three stages developed symptoms of root and crown rot in 100% of inoculated plants, with no observed vascular discoloration. Fifty days after inoculation, all three stages of C. maxima × C. moschata and zucchini remained symptomless. Loofah and watermelon germinated poorly or not at all when inoculated at the pregermination stage. Fifteen to fifty days after inoculation, 100% of inoculated cucumber and melon plants developed symptoms. Watermelon plants inoculated at the 10 or more true-leaf stage did not develop disease symptoms. No symptoms developed on noninoculated control plants. F. oxysporum was reisolated from infected roots, crowns, and stems of inoculated plants, confirming Koch's postulates. The main symptoms on cucumber infected by F. oxysporum f. sp. cucumerinum are wilt, yellowing, and vascular discoloration. In contrast, based on inoculation of the host differentials and the resulting disease symptoms found in this study, the fungus was identified as F. oxysporum f. sp. radicis-cucumerinum (1). To our knowledge, this is the first report of F. oxysporum f. sp. radicis-cucumerinum causing root and crown rot in cucumber in Spain. Reference: (1) D. J. Vakalounakis. Plant Dis. 80:313, 1996.

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