The present study evaluated the ability of different extracts of cinnamon and black cumin seeds to inhibit the growth of the phytopathogenic fungus Rhizoctonia solani and its extracellular cell wall degrading enzymes. Concentrations of 300 and 450 ppm of methylene chloride and hexane extracts of cinnamon completely inhibited the growth of R. solani after 72 hours of incubation at 25±1°C in vitro. Methylene chloride or hexane extracts of black cumin seeds at 4000 ppm after 72 hours inhibited the growth of R. solani by 37 and 39% respectively. Moreover, black cumin seed hexane extract at 2000 ppm inhibited 55% and 38% of the activity of pectin lyase (PL) and polygalacturonase (PG) respectively. In addition, the methanolic extract of black cumin seeds at 2000 ppm exhibited a significant reduction of exo-protease activity (74.8%). GC-MS analysis results showed that linoleic acid is the main component of the fixed oil fraction of black cumin seed hexane extract while (E) cinnamaldehyde is the main component in both hexane and methylene chloride extracts of cinnamon. HPLC-MS analysis of black cumin seeds methanolic extract showed that amentoflavone was the main component. Docking was used to identify the major component interaction with pectin lyase A and exo-protease.

The present study evaluated the ability of different extracts of cinnamon and black cumin seeds to inhibit the growth of the phytopathogenic fungus Rhizoctonia solani and its extracellular cell wall degrading enzymes. Concentrations of 300 and 450 ppm of methylene chloride and hexane extracts of cinnamon completely inhibited the growth of R. solani after 72 hours of incubation at 25±1°C in vitro. Methylene chloride or hexane extracts of black cumin seeds at 4000 ppm after 72 hours inhibited the growth of R. solani by 37 and 39% respectively. Moreover, black cumin seed hexane extract at 2000 ppm inhibited 55% and 38% of the activity of pectin lyase (PL) and polygalacturonase (PG) respectively. In addition, the methanolic extract of black cumin seeds at 2000 ppm exhibited a significant reduction of exo-protease activity (74.8%). GC-MS analysis results showed that linoleic acid is the main component of the fixed oil fraction of black cumin seed hexane extract while (E) cinnamaldehyde is the main component in both hexane and methylene chloride extracts of cinnamon. HPLC-MS analysis of black cumin seeds methanolic extract showed that amentoflavone was the main component. Docking was used to identify the major component interaction with pectin lyase A and exo-protease.

Decline of grapevine due to soil borne fungi was surveyed during 2013- 2015 summer growing seasons at El-Fayoum, El-Gharbeia and El-Beheira governorates, Egypt, Syndromes of declined grapevine plants included growth retardant of shoot system and root-rot as well as decrease of grapevine fruit yield  quality. Isolation trails from root of declined trees of different grapevine cultivars i.e., superior, flame seedless, King robi and crimson was carried out. The most soil borne fungi associated with root-rotted grapevine were Fusarium oxysporum Schlechtend, Fusarium solani (Mart.) Sacc, Botryodiplodia theobromae, Rhizoctonia solaniKuhn and Macrophomina phaseolina(Tassi) Gold. Fusarium spp. are the main fungal associated with different infection types of declined root of grapevine either a singly or in combination with B. theobromae or R. solani as second infection type and third infection type with B. theobromae + R. solani. Under soil artificially infested with 5% (w/w) of each fungal isolates inocula of fourteen isolates obtained were varied for causing wilt and root-rot symptoms of grapevine trees and reducing growth parameters plant height, root length, root size, fresh and dry weight of shoot and root than the control. Botrydiplodia theobromae isolate No. (7)was the most caused root-rot and disease severity of shoot and root of grapevine plant(100%)  followed by Fusarium avenacum caused (87.5%) of root –rot and disease severity of shoot and root. Fouthermore, Fusarium avenacum isolate was the most fungal isolate in reducing growth parameters expect root length.  This is first record that Fusarium avenacum as a causal organism causing root rot disease of grapevine in Egypt.

Faba bean (Vicia faba L.) seeds cv. Misr 1  were treated with Bion (5 mM), salicylic acid (5 mM) as chemical inducers as well as Paenibacillus polymyxa and Trichoderma harzianum as biotic inducers to study their effect on the infection with Rhizoctonia solani and Fusarium solani f. sp. fabae under greenhouse and field conditions.           Under greenhouse conditions (Agricultural Research Centre, Giza) all treatments induced reduction in the percentages of pre- and post-emergence damping off caused by R. solani or F. solani f. sp. fabae compared to untreated control. The highest percentage of survived plants was achieved from the inducer Bion (92 % and 88%) compared with untreated control (40% and 36%) in the presence of R. solani or F. solani f. sp. fabae respectively. Meantime, there was no significant difference between the Bion and the fungicide Rizolex –T (3 g/Kg seeds) treatments. However, all treatments caused significant increase in the figures of plant height, shoot and root dry weight, nodules number/plant and nodules dry weight over the control treatment grown in infested soil by R. solani or by F. solani f. sp.  fabae. The highest values of all growth parameters under study were recorded on faba bean plants check (healthy plants) grown in disinfested soil followed by Bion and Rizolex –T treatments in the presence of R. solani or F. solani f. sp.  fabae. There was no significant difference between Bion and Rizolex-T treatments with exception of nodules number and nodules dry weight /plant in the presence of R. solani. On the contrary, there was significant difference between Bion and Rizolex-T treatments with exception of plant height in the presence of F. solani f. sp.  fabae.           Under field conditions at Giza (Giza Governorate) and Etay El-Baroud (El- Behira Governorate) Agricultural Research Stations during winter season 2013-2014, all the treatments significantly decreased the percentage of pre- and post-emergence damping-off and increased the percentage of survived plants compared with untreated control in two locations with exception of post-emergence percentage figures at Giza Agricultural Research Station. Regarding survived plants, there were no significant differences between the Bion (89.5% and 86.5%) as well as Rizolex-T (90.9% and 88.8%) treatments compared with untreated control (68.3% and 64.3%) at Giza and Etay El-Baroud Agricultural Research Stations respectively. However, all inducer treatments significantly improved growth parameters (i.e. plant height, number of pods/plant, seed weight /plant and one hundred seed weight) as well as yield compared to the untreated control in the two locations. Higher increase in seed yield (ton /feddan) was obtained with Rizolex-T and Bion treatments (62.2% and 57.9%) respectively, followed by salicylic acid and P. polymyxa with (39.4% and 28.4 %) respectively, increasing over the untreated control calculated as means of the two locations.         Activities of peroxidase (PO), polyphenol oxidase (PPO) enzymes and phenol content were determined in faba bean plants treated with different inducers. Bion treatment showed the highest increase in PO and PPO activity, total and free phenols followed by salicylic acid treatment in the presence of R. solani or F. solani f. sp.  fabae.

Rhizoctonia solani is considered one of the most harmful pathogens affecting green bean productivity. Phaseolus vulgaris, L. cv. paulista seeds were subjected to UV-C for 60 min. and/or immersed in glycine betaine (GB, 5 mM) for 24 hours to stimulate plant biochemical defenses against R. solani. After treatments, seeds were sown in soil infested with R. solani, then seedling samples were collected after two weeks to evaluate plant resistance and some antioxidant enzymes activities. The results clearly demonstrated that disease index (DI) was highly reduced by GB (54.7%) followed by UV+GB (38.3%) and UV (35.6%). Seed treatment with UV-C for 60 min or GB (5 mM) for 24 h alone or together enhanced plant rooting in infected seedlings comparing with control. Also, there was a high correlation between the levels of lipid peroxidation and Rhizoctonia root rot disease index. Seed treated with UV-C, GB or both mitigated the effect of infection on the lipid peroxidation (Malondialdehyde levels) with percentages of 26.8, 40.2 and 29.3% respectively in comparison with the infected control. Regarding to the plant defensive enzymes, GB was the only treatment that triggered a significant increment in the superoxide dismutase (SOD) activity in roots of both infected and non-infected seedlings as compared to the control. On the other hand, guaiacol peroxidase (G-POD) and polyphenol oxidase (PPO) activities were elevated by all treatments in infected plant roots in comparison with control. The maximum activity for G-POD was attained with UV treatment (9042.5 U.mg-1 protein) followed by GB+UV, GB and infected control with values of 7776.5, 7152.4 and 6508.8 U.mg-1 protein, respectively. Similarly, PPO exhibited higher activities with significant differences in all treatments over the infected control with percentages of 54, 59.4 and 48.7% for UV, GB and UV+GB respectively. Finally, it can be concluded that treatment of green bean seeds with UV-C and GB enhanced green bean seedlings tolerance to R. solani by activation of the antioxidant enzymes and activation of defense-related enzymes like polyphenol oxidase. The results of combination of UV-C and GB treatments indicated the absence of synergetic effects in induction of plant tolerance.

ABSTRACT The effect of different nitrogen sources (glucosamine sulfate, ammonium sulfate, aspartic acid, phenylalanine and peptone) in comparison to sodium nitrate, the major nitrogen compound in basal agar Czapek’s synthetic medium growth were studied on the linear growth of Rhizoctonia solani and its pathogenicity on faba bean germinated seeds. Ammonium sulfate exhibited faster liner growth and showed the same effect as the basal medium with sodium nitrate while, glucosamine sulfate showed less growth rate compared with sodium nitrate. Glucosamine sulfate and ammonium sulfate showed significant reduction in number of infection cushions which led to significant decrease of disease index in vitro. Our results showed strongly significant positive correlations between disease index and both of diameters of hyphae and number of infection cushions while, very weak correlation coefficient was found between disease index and linear growth of R. solani. Under greenhouse conditions, glucosamine sulfate or peptone as a sole nitrogen sources in food requirements of Rhizoctonia solani inoculum depressed the virulence of the fungus. The effect of different amounts of glucosamine sulfate was determined on fungal growth rate, infection cushions, disease index in vitro and polyphenol oxidase activity. Increasing amount of glucosamine sulfate showed significantly reduction of growth rate in comparison to the basal medium with sodium nitrate. All seeds subjected to R. solani grown on different amount of glucosamine sulfate showed the lower number of infection cushions, disease index and polyphenol oxidase activity compared with sodium nitrate. Under greenhouse conditions, disease index showed significantly decreased effect when glucosamine sulfate used as soil applications and showed better effect on shoot weight and root weight compared with control plants treated with sodium nitrate. Our study proposes that glucosamine sulfate may acts as controlling factor of pathogenicity genes of R. solani. Key words: Rhizoctonia solani, faba bean, Vicia faba, nitrogen sources, glucosamine sulfate, pathogenicity.

Preparationof either Bacillus thuringiensis or Trichoderma harzianum  were used as seed coating or soil application for management of root-knot and root rot disease complex caused by the root-knot nematode, Meloidogyne javanica and the fungus Rhizoctonia solani on soybean plants. Number of galls, root galling, egg masses and disease severity were reduced sharply on plants treated with both biocontrol agents, either as seed or soil application compared with non-treated plants. Soil application with both biocontrol agents was the best method in reducing nematode and fungus disease severity. Plant growth parameters i.e. fresh shoot and root weight, dry weight and number of pods and bacterial nodules were markedly increased with all treatments of biocontrol agent either with seed or soil treatment compared to plants grown in infested soil with either pathogens alone or combined. Results show that plant survival was more affected when R. solani was alone or combined with M. javanica. Seed coating was considered the effective method in increasing survival plants. The biochemical analysis of treated plants with both biocontrol agents were affected compared to non-treated plants grown in pathogen infested soil. The biochemical parameters i.e. chlorophyll A and B, carotein, phenols and amino acids were enhanced in bioagent treated plants compared to non-treated plants