scholarly journals Investigation of optimum conditions for the growth of Fusarium solani EGY1 causing root rot of guar (Cyamopsis tetragonoloba L.)

2017 ◽  
Vol 9 (4) ◽  
pp. 2249-2254
Author(s):  
Simranjit Singh ◽  
Upasana Rani ◽  
U.S. Tiwana ◽  
Devinder Pal Singh ◽  
Asmita Sirari

Guar gum (Galactomannan) is extracted from Guar (Cluster bean), which is extensively used in petroleum, food and pharmaceutical industry. Root rot of guaris caused by Fusarium solani EGY1 under Punjab, having sub-tropical climatic conditions. This study was undertaken to evaluate different culture media, grain substrates (sorghum, maize, cowpea, guar and pearl millet), temperatures (20, 25, 30, 35oC), pH levels (5.0, 6.0, 7.0, 8.0), light and darkness for the identification of optimum conditions for the growth and sporulation of the fungus. Czapek’s dox media was found to be best for growth (84.65 mm) and sporulation (1.8 x 104microconidia and 3.0 x 104 macro conidia) of fungus. For mass multiplication of the fungus, sorghum grains proved to be the best substrate. The fungus showed maximum radial growth at temperature of 25oC (84.36 mm) and pH of 6.0 (84.43 mm) whereas sporulation was highest at 30oC (2.0 x 104 microconidia and 3.2 x 104 macroconidia) and pH of 8.0 (1.8 x 104 microconidia and 3.1 x 104 macroconidia) respectively. Continuous light favoured radial growth (84.62 mm) whereas sporulation (1.8 x 104 microconidia and 3.1 x 104 macroconidia) was favoured by darkness.

Plant Disease ◽  
2019 ◽  
Vol 103 (12) ◽  
pp. 3234-3243
Author(s):  
David R. Cruz ◽  
Leonor F. S. Leandro ◽  
Gary P. Munkvold

Fusarium oxysporum (Fo) is an important pathogen that reduces soybean yield by causing seedling disease and root rot. This study assessed the effects of pH and temperature on Fo fungal growth and seedling disease. In an in vitro assay, 14 Fo isolates collected from symptomatic soybean roots across Iowa in 2007 were grown on artificial culture media at five pH levels (4, 5, 6, 7, and 8) and incubated at four temperatures (15, 20, 25, or 30°C). In a rolled-towel assay, soybean seeds from Fo-susceptible cultivar Jack were inoculated with a suspension of a pathogenic or a nonpathogenic Fo isolate; both isolates were previously designated for their relative aggressiveness in causing root rot at 25°C. The seeds were placed in rolled germination paper, and the rolls were incubated in all combinations of buffer solutions at four pH levels (4, 5, 6, and 7), and four temperatures (15, 20, 25, or 30°C). There was a significant interaction between temperature and pH (P < 0.05) for in vitro radial growth and root rot severity. Isolates showed the most in vitro radial growth after incubation at pH 6 and 25°C. For the rolled-towel assay, the pathogenic isolate caused the most severe root rot at pH 6 and 30°C. Gaussian regression analysis estimates for optimal conditions were pH 6.3 at 27.1°C for maximal fungal growth and pH 5.9 at 30°C for maximal root rot severity. These results indicate that optimal pH and temperature conditions are similar for Fo growth and disease in soybean seedlings and suggest that Fo may be a more important seedling pathogen when soybeans are planted under warm conditions in moderately acidic soils.


1994 ◽  
Vol 40 (2) ◽  
pp. 113-119 ◽  
Author(s):  
M. S. Reddy ◽  
R. K. Hynes ◽  
G. Lazarovits

One hundred and twenty diverse bacterial strains were screened under greenhouse conditions for their ability to protect white bean seedlings from preemergence damping-off caused by Pythium ultimum and Rhizoctonia solani and postemergence root rot by Fusarium solani f.sp. phaseoli. Preemergence mortality or root rot increased with an increase in the inoculum concentration of fungal isolates. For further testing, 200 propagules/g soil of P. ultimum, 3 propagules/g soil of R. solani, and log 3 conidia/g vermiculite of F. solani f.sp. phaseoli were used, as these rates provided an optimal level (approximately 50%) of disease severity. Bacterial strains suspended in sterile distilled water were added to pathogen-amended soil or vermiculite at log 7 colony-forming units/g soil or vermiculite prior to seeding. Final healthy stand and root rot were recorded 4 weeks after planting. Nine bacterial strains on P. ultimum, five on R. solani, and nine on F. solani f.sp. phaseoli provided significant (P = 0.05) suppression of disease severity compared with the nonbacterized control. Bacterial strains were also tested in vitro against the mycelial growth of the fungi on solid and liquid media. There was no relationship between the ability of bacterial strains to inhibit fungal vegetative growth on solid culture media and their ability to suppress pathogen activity in the greenhouse, but, for a few strains, the reduction in disease was linked to reduced growth of the pathogens in liquid media.Key words: White bean, damping-off, root rot, Pythium ultimum, Rhizoctonia solani, Fusarium solani f.sp. phaseoli.


Author(s):  
A N. Kabanov ◽  
◽  
S.A. Kabanova ◽  

Dendrochronological analysis was carried out in forest cultures of Pinus sylvestris of different ages growing in the green zone of Nur-Sultan city. It was found that the value of the annual radial growth is subject to a cycle with a period of 10-11 years. This is due to climatic conditions, in particular, with periods of solar insolation, which is confirmed by researches of other authors.


Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 334
Author(s):  
Norbert Szymański ◽  
Sławomir Wilczyński

The present study identified the similarities and differences in the radial growth responses of 20 provenances of 51-year-old European larch (Larix decidua Mill.) trees from Poland to the climatic conditions at three provenance trials situated in the Polish lowlands (Siemianice), uplands (Bliżyn) and mountains (Krynica). A chronology of radial growth indices was developed for each of 60 European larch populations, which highlighted the interannual variations in the climate-mediated radial growth of their trees. With the aid of principal component, correlation and multiple regression analysis, supra-regional climatic elements were identified to which all the larch provenances reacted similarly at all three provenance trials. They increased the radial growth in years with a short, warm and precipitation-rich winter; a cool and humid summer and when high precipitation in late autumn of the previous year was noted. Moreover, other climatic elements were identified to which two groups of the larch provenances reacted differently at each provenance trial. In the lowland climate, the provenances reacted differently to temperature in November to December of the previous year and July and to precipitation in September. In the upland climate, the provenances differed in growth sensitivity to precipitation in October of the previous year and June–September. In the mountain climate, the provenances responded differently to temperature and precipitation in September of the previous year and to precipitation in February, June and September of the year of tree ring formation. The results imply that both climatic factors and origin (genotype), i.e., the genetic factor, mediate the climate–growth relationships of larch provenances.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Alemayehu Dugassa ◽  
Tesfaye Alemu ◽  
Yitbarek Woldehawariat

Abstract Background Faba bean (Vicia faba L.) cultivation is highly challenged by faba bean black root rot disease (Fusarium solani) in high lands of Ethiopia. To ensure sustainable production of faba beans, searching for eco-friendly disease management options is necessary to curb the progress of the disease timely. The indigenous biocontrol agents that suit local environments may effectively strive with in-situ microorganisms and suppress local pathogen strains. This study aimed to screen antagonistic indigenous compatible Trichoderma and Pseudomonas strains against Fusarium solani. In the pathogenicity test, soil-filled pots were arranged in complete random block design and sown with health faba bean seeds. The effect of some fungicides was evaluated against Fusarium by food poisoning methods to compare with the biocontrol agents. The antagonistic efficacy of biocontrol agents and their compatibility was investigated on Potato dextrose agar medium. Results Fusarium solani AAUF51 strain caused an intense root rotting in faba bean plant. The effect of Mancozeb 80% WP at 300 ppm was comparable with Trichoderma and Pseudomonas strains against Fusarium. The mycelial growth of test the pathogen was significantly (P ≤ 0.05) reduced to 86.67 and 85.19% by Trichoderma harzianum AAUW1 and Trichoderma viridae AAUC22 strains in dual culture, respectively. The volatile metabolites of Pseudomonas aeruginosa AAUS31 (77.78%) found the most efficient in reducing mycelial growth of Fusarium followed by Pseudomonas fluorescens AAUPF62 (71.11%) strains. The cell-free culture filtrates of Pseudomonas fluorescens AAUPF62 and Pseudomonas aeruginosa AAUS31 were more efficient than the Trichoderma strain in reducing the growth of Fusarium isolates. There was no zone of inhibition recorded between Trichoderma harzianum AAUW1, Trichoderma viridae AAUC22, Pseudomonas aeruginosa AAUS31, and Pseudomonas fluorescens AAUPF62 strains, hence they were mutually compatible. Conclusions The compatible Trichoderma and Pseudomonas strains showed antagonistic potentiality that could be explored for faba bean protection against black root rot disease and might have a future dual application as biocontrol agents.


1977 ◽  
Vol 89 (1) ◽  
pp. 235-238 ◽  
Author(s):  
P. E. Russell ◽  
A. E. A. Mussa

SummaryTwo systemic fungicides, benomyl and thiabendazole, were more active than the non-systemic fungicide Drazoxolon in inhibiting fungal growth in vitro. A similar pattern was obtained in glasshouse trials with benomyl and thiabendazole giving adequate protection at low concentrations while Drazoxolon was ineffective unless applied at 50% the commercial product concentration. A field trial using thiabendazole, Drazoxolon and a mixture of benomyl and thiram confirmed the glasshouse results.Some phytotoxicity was noticed with high concentrations of both benomyl and thiabendazole, but satisfactory disease control was achieved using fungicide concentrations which did not induce phytotoxicity.


Revista CERES ◽  
2018 ◽  
Vol 65 (3) ◽  
pp. 291-295 ◽  
Author(s):  
Fernando Marcelo Chiamolera ◽  
Antonio Baldo Geraldo Martins ◽  
Pedro Luiz Martins Soares ◽  
Tatiana Pagan Loeiro da Cunha-Chiamolera

ABSTRACT Root-knot nematode Meloidogyne enterolobii is the main phytosanitary problem of guava cultivation in Brazil. Among the strategies to manage the problem, the best prospects are in identifying or developing cultivars or rootstocks that are resistant to this nematode. To identify plants with potential as rootstocks for guava, the reaction of araçá (wild guava) to M. enterolobii was assessed in a greenhouse experiment. Seven araçá species were evaluated (Eugenia stipitata, Psidium acutangulum, P. cattleyanum ‘yellow’, P. friedrichsthalianum, P. guajava var. minor, P. guineense, and Psidium sp.). The plants were inoculated with a suspension of 3,000 eggs of M. enterolobii, using eggplant as control treatment. The parameters fresh root mass, number of eggs and second stage juveniles (J2) per root system, the reproduction factor (RF = Pf/Pi), and araçá reaction were determined during the experiment. RF of the araçá species E. stipitata, P. cattleyanum ‘yellow’, and P. friedrichsthalianum was less than one (RP < 1), therefore resistant to M. enterolobii. The araçá trees had good root system development and the susceptible plants showed many root galls, high number of eggs and J2, and Fusarium solani and Rhizoctonia solani root rot. The araçá species, P. cattleyanum ‘yellow’, P. friedrichsthalianum, and E. stipitata are resistant to M. enterolobii and can be tested as potential guava rootstocks.


Plant Disease ◽  
2008 ◽  
Vol 92 (8) ◽  
pp. 1197-1200 ◽  
Author(s):  
V. N. Bilgi ◽  
C. A. Bradley ◽  
S. D. Khot ◽  
K. F. Grafton ◽  
J. B. Rasmussen

Fusarium root rot of dry bean (Phaseolus vulgaris), caused by Fusarium solani f. sp. phaseoli, is a major yield-limiting disease in North Dakota and Minnesota. Although a few sources of partial resistance are available, most commercial cultivars grown in this region are susceptible, especially in the red kidney bean market class. This study evaluated three methods of screening for resistance to Fusarium root rot. A sand-cornmeal inoculum layer method, spore suspension method, and paper towel method were used to evaluate 11 dry bean genotypes for resistance to Fusarium root rot under growth-chamber conditions. These same genotypes were also evaluated in field trials at Fargo, ND, and Park Rapids and Perham, MN, in 2005. In all trials, the small red genotype VAX 3 was found to have a consistently high level of resistance to Fusarium root rot and could be used as a source of resistance by dry bean breeders. Correlation analyses between field and growth-chamber root rot ratings indicated that all three growth-chamber methods had significantly (P ≤ 0.05) positive correlations with field results from Perham and Fargo, which suggests that all three methods could be used to screen germplasm efficiently for resistance to Fusarium root rot.


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