91 research outputs found
Structural and Biochemical Changes in Salicylic-Acid-Treated Date Palm Roots Challenged with<i>Fusarium oxysporum</i>f. sp.<i>albedinis</i>
No full textHistochemical and ultrastructural analyses were carried out to assess structural and biochemical changes in date palm roots pretreated with salicylic acid (SA) then inoculated withFusarium oxysporumf. sp.albedinis(Foa). Flavonoids, induced proteins, and peroxidase activity were revealed in root tissues of SA-treated plants after challenge by Foa. These reactions were closely associated with plant resistance to Foa. Host reactions induced after inoculation of SA-treated plants with Foa included the plugging of intercellular spaces, the deposition of electron-dense materials at the sites of pathogen penetration, and several damages to fungal cells. On the other hand, untreated inoculated plants showed marked cell wall degradation and total cytoplasm disorganization, indicating the protective effects provided by salicylic acid in treated plants.</jats:p
“Secreted in Xylem” Genes (SIX Genes): Relationship to the Aggressiveness of Fusarium oxysporum f. sp. albedinis
No full textFusarium oxysporum f. sp. Albedinis (Foa) is the causal agent of Bayoud disease, responsible for the loss of 75% of date palm trees in Morocco and posing a threat to its cultivation across North Africa. This study examined ten Foa isolated from various Moroccan locations for the presence of the transposable element Fot1 and the distribution of “Secreted in Xylem” (SIX) genes. Pathogenicity assays on date palm seedlings revealed varying levels of aggressiveness among isolates, with a positive correlation between aggressiveness and SIX gene count. Highly aggressive isolates harbored 9–12 SIX genes, while hypo-aggressive and moderately aggressive isolates carried 0–6. SIX2, SIX6, SIX7, SIX11, SIX12, and SIX13 were differently dispersed among aggressive isolates, whereas SIX12 and SIX13 were present in all aggressive isolates, suggesting their potential role in virulence. This study is the first to highlight a correlation between Foa aggressiveness and SIX gene distribution, providing a foundation for future functional analyses to elucidate their role in pathogenicity
Genetic engineering of lignin biosynthesis in poplar and effects on kraft pulping
No full textinfo:eu-repo/semantics/publishe
Lignification: are lignins biosynthesized via simple combinatorial chemistry or via proteinaceous control and template replication?
No full textThe Effects of Plant Extracts of<i>Reynoutria sachalinensis</i>on Powdery Mildew Development and Leaf Physiology of Long English Cucumber
No full textSalt compounds as control agents of late blight and pink rot of potatoes in storage
No full textEach year, potato late blight [Phytophthora erythroseptica] and pink rot [PhytolAthora erythroscptica] are responsible for significant postharvest economic losses. Because of restrictions on the use of synthetic fungicides on food, there is Currently a need for less toxic, disease-controlling compounds for postharvest application. To address this need, the preventative and curative effects, as well as seed piece phytotoxicity, of various salt compounds were tested using live tubers of the potato 'Superior'. Compounds were tested as dips at the concentrations 0.002, 0.02, 0.2 mol/L and compared with a distilled water dip as a control. Tubers were inoculated with sporangia of P infestans or active zoospores of P. erythroseptica either before or after treatment with the various compounds. When concentration data were pooled and grouped means were tested for significant differences (P < 0.05). potassium sorbate, sodium metabisulfite, alum, sodium hypochlorite, copper sulfate pentahydrate, acetic acid, and Penncozeb (R) 75DF applied curatively provided disease inhibition that was significantly greater than that of the control for both late blight and pink rot. When applied as a preventative treatment, all compounds were significantly different (P < 0.05) from the untreated control in the inhibition of pink rot; however, only sodium metabisulfite, sodium hypochlorite, copper sulfate pentahydrate, and Penncozeb 75DF significantly reduced the severity of late blight. Phytotoxicity was observed when sodium hypochlorite, sodium metabisuffite, acetic acid, and copper sulfate pentahydrate were applied as seed piece treatments, at a concentration of 0.2 mol/L. Our studies suggest there is a potential for the use of selected salt compounds for control of postharvest diseases of potato.PT: J; CR: ANDRIVON D, 1995, EUR J PLANT PATHOL, V101, P527 BENSON DM, 1993, PHYTOPATHOLOGY, V83, P1303 CHOURASIA HK, 1993, LETT APPL MICROBIOL, V17, P204 DAAYF F, 1999, AM J POTATO RES, V76, P287 DAAYF F, 2000, CAN J PLANT PATHOL, V22, P110 DROBY S, 2003, POSTHARVEST BIOL TEC, V27, P127 FURUYA H, 1999, PHYTOPATHOLOGY, V89, P47 GOULD GW, 1991, FOO DPRESERVATIVES, P72 HERVIEUX V, 2002, PLANT DIS, V86, P1014 JAMES C, 1971, MANUAL ASSESSMENT KE KABARA JJ, 1991, FOOD PRESERVATIVES, P44 KATO M, 1997, PHYTOPATHOLOGY, V87, P973 MECTEAU MR, 2002, MYCOL RES 6, V106, P688 MEYER JR, 1994, PHYTOPATHOLOGY, V82, P1114 MILLS AAS, 2004, POSTHARVEST BIOL TEC, V34, P341 MINCHONA R, 1992, PHYSIOL PLANTARUM, V85, P417 MUCHOVEJ JJ, 1980, PHYTOPATHOLOGY, V70, P1212 OLIVIER C, 1998, PLANT DIS, V82, P213 OLIVIER C, 1999, PLANT DIS, V83, P814 PALOU L, 2002, PEST MANAG SCI, V58, P459 PETERS RD, 1998, THESIS U GUELPH GUEL PETERS RD, 2001, AM J POTATO RES, V78, P39 PETERS RD, 2001, PLANT PATHOL, V50, P302 PETERS RD, 2003, CAN J PLANT PATHOL, V25, P33 PUNJA ZK, 1993, PLANT DIS, V77, P989 RIDAO A, 1990, P 11 TRIENN EUR ASS, P317 SALMOND CV, 1984, J GEN MICROBIOL, V130, P2845 SECOR GA, 1999, CAN J PLANT PATHOL, V21, P213 SHITOLE DM, 2000, J MAHAASHTRA AGR U, V25, P179 ZAR JH, 1999, BIOSTATISTICAL ANAL; NR: 30; TC: 0; J9: CAN J PLANT PATHOL; PG: 6; GA: 941IHSource type: Electronic(1
Differential pathogenicity on potato and tomato of Phytophthora infestans US-8 and US-11 strains isolated from potato and tomato
No full textThirty-two isolates of Phytophthora infestans from potato and tomato tissues (US-11 strain, 8 isolates from potato and 6 from tomato; US-8 strain, 11 from potato and 7 from tomato), collected in Canada in 1997 and 1998 were tested for their differential pathogenicity on four potato and four tomato cultivars. This study clearly showed that US-8 and US-11 strains, representing the two main genotypes found in Canada since 1996, can both infect the foliage of potato and tomato plants. US-11 isolates from potato infected both tomato and potato at similar levels. Conversely, US-8 from potato caused lower colonization levels on tomato than on potato. Regardless of the host origin, it was found that US-8 and US-11 cause similar levels of colonization on potato, while US-11 isolates are more aggressive than US-8 on tomato. Thus, the genotype identity of a P. infestans isolate may inform us about its pathogenicity potential on the two hosts. Such information might be helpful towards time and space management of late blight caused by P. infestans, especially when these two crops are cultivated close to each other, or when other solanaceae species are growing nearby
How Fusarium graminearum affects intermediate wheatgrass and its mycobiome
No full textAn emerging crop, intermediate wheatgrass (IWG) is resistant to the natural occurrence of most important cereal diseases and is currently under domestication to improve its yield. An IWG population consisting of two parental lines and 154 individual F1 progenies were inoculated with F. graminearum spores in a field setting to check their performance against Fusarium head blight (FHB) over two consecutive years. The higher humidity in 2022 lead to higher FHB severity and incidence, and higher DON (deoxynivalenol) mycotoxin accumulation than in 2021. DON was mostly restricted to the chaff in 2021, whereas in 2022, DON was found in the grain as well. Considering all the FHB aspects checked in this experiment, four IWG progeny individuals (plants: P-17, P-43, P-107, and P-139) were found to consistently perform better than the parental lines and the other progeny individuals during both years.
The second part of this thesis analyzed the influence of F. graminearum on the mycobiome of IWG spikelet and flag leaf samples from two different locations, Winnipeg and Carman, MB. A total 372 IWG samples (half of which were inoculated with F. graminearum [Winnipeg] and the other half, not [Carman]) were used for fungal community profiling via ITS amplicon sequencing using PacBio technology. There were significant differences in the fungal community among the IWG spike samples from Winnipeg and Carman. As expected, F. graminearum dominated IWG spike mycobiomes at the inoculated Winnipeg site, whereas in Carman, Alternaria dominated. Also, the presence of F. graminearum seemed to influence the broader spike mycobiome and the presence of beneficial fungi was less where F. graminearum dominated. The mycobiome data also revealed that the pathogenic fungi Alternaria, Nigrospora, Septoriella, Stemphylium, Claviceps, Bipolaris, and Drechslera can become potential threats to IWG in the future.
The last part of this thesis sheds light on the interaction between F. graminearum and another agriculturally important fungus, Claviceps purpurea. In planta interactions showed that C. purpurea can negatively affect infection by F. graminearum only if C. purpurea was introduced first into the plant site, but further investigation of this is necessary for confirmation.Faculty of Science, University of Manitoba
University of Manitoba Collaborative Research Program (UCRP)
Canadian Agricultural Partnership
The Land InstituteFebruary 202
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