الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Chickpea (Cicer arietinum L.) is one of the most essential pulse crops grown in over fifty countries; especially it is a highly nutritious grain legume crop.
Damping off, wilt and stem and root rot diseases are important serious fungal diseases which attack chickpea affecting growth and crop parameters so that causing great losses in quality and the total seed yield under greenhouse and field conditions.
In the present work, we study these diseases incidence and its pathogenic fungal agents and methods of controlling them.
Field survey during 2016-2017 growing season for damping off, wilt and stem rot diseases of chickpea in six different governorates in Egypt –indicated that the highest percentage of chickpea disease incidence was recorded in Kafr-El-Sheik governorate followed Beheira, Gharbia, Giza, Beni-Suef), while the lowest percentage of diseases incidence was recorded in Assiut governorate.
Isolation, purification and identification of 104 infected samples of chickpea plants collected from 11 field in six governorates showed that The fungus Fusarium oxysporum recorded the highest frequency percentage of the isolated fungi being 50% followed by Rhizoctonia solani 28%, Sclerotinia sclerotiorum 9%, Fusarium solani 3%, Fusarium spp. 8%, and Scleritium rolfsii 2%.
After morphological identification and Blast analysis, molecular characteristics of the most common tested pathogens showed that the DNA sequences have been deposited in the NCBI GenBank by the NCBI accession numbers MW926317 for Sclerotinia sclerotiorum, MW926318 for Fusarium oxysporum and MW926319 for Rhizoctonia solani.
Pathogenicity test revealed that all isolates of Fusarium oxysporum, Rhizoctonia solani or Sclerotinia sclerotiorum were capable for infecting chickpea plant causing damping- off, wilt diseases. F. oxysporum, R. solani and S. sclerotiorum isolated from chickpea which isolated from Gharbia, Kafrelsheikh and Beheira governorate respectively, were the most virulent isolates.
Antagonism of the bioagents and the fungicide Rizolex-T towards the pathogenic fungi illustrated that all the bioagents significantly inhibit the mycelial growth of the three tested pathogenic fungi (Fusarium oxysporum, Rhizoctonia solani or Sclerotinia sclerotiorum) as followed: Trichoderma viride (70.37, 57.43 and 70.3 %), Trichoderma harzianum (64.8, 59.26 and 70.32%), T. viride + T. harzianum (62.96, 68.52 and 75.93%) Pseudomonas fluorescence (57.41, 55.56 and 66.67%), Bacillus subtilis (55.56, 57.40 and 64.81%), Ps. fluorescens + B. subtilis (74.07, 64.81and 74.07 %) and Serratia marcescens (46.30, 53.70and 55.56%) towards F. oxysporum, R. solani or S. sclerotiorum respectively, while showed that all the five tested concentrations of Rizolex-T i.e., 1, 5, 10, 15 and 25 ppm significantly inhibit the mycelial growth of the three tested pathogenic fungi.
Under greenhouse conditions, (AMF+ T. viride +T. harzianum) showed that the higtest result in the decreasing of the percentages of pre- and post-emergence damping-off and/or wilt between all the bioagents against F. oxysporum, R. solani or S. sclerotiorum.
The tested bioagent treatments significantly improved chickpea growth parameters, i.e., plant height, fresh weight and dry weight. (Mycorrhizae + T. viride + T. harzianum) has the highest results between all bio agents compared to the untreated infested control.
Under field conditions, reduction of disease severity was reflected on increasing in crop yield, particularly in using, Rizolex-T and (AMF+ T. viride +T. harzianum) against the mentioned diseases. Also, all treatments, significantly improved chickpea growth and crop parameters compared to the untreated control and the highest significant increase in all parameters was recorded with the treatments Rizolex-T then (Mycorrhizae + T. viride + T. harzianum).
Results showed that all treatments were significant in increasing enzyme activities and phenol content of the chickpea plants . The highest increase of β-1,3 glucanase, peroxidase, polyphenol oxidase activities and phenol compounds as compared to the untreated control was achieved with (T. harzianum + T. viride) treatment either in the presence of F. oxysporum, R. solani or S. sclerotiorum.
Mycorrhizae treatment individually had significant root colonization percentage of mycorrhizal and its spores number higher than combining (Mycorrhizae + T. viride + T. harzianum) or Rizolex-T compared to untreated infested and non-infested soil (control) in the greenhouse and field conditions.
All treatments recorded markedly increased in nitrogen, phosphorus and potassium contents of chickpea grown compared to the control after 45 days from cultivation. (Mycorrhizae + T. viride + T. harzianum) and (T. viride + T. harzianum) were the hightest among all treatments in nitrogen, phosphorus and potassium contents unlike Serratia marcescens was the lowest under field conditions.
Under greenhouse and field conditions, all treatments significantly improved the nodulation status of chickpea plants and nitrogense activity compared to untreated infested and non-infested soil (control). (Mycorrhizae + T. viride +T. harzianum ) had the highest results between all treatments.