Fungi as Potential Biocontrol Agents Against  Convolvulus arvensis  and  Portulaca oleracea  Infesting the Agroecosystems of Egypt

Ibrahim, Nevin; Tawfik, Merha

doi:10.21608/ejm.2019.17443.1117

Fungi as Potential Biocontrol Agents Against Convolvulus arvensis and Portulaca oleracea Infesting the Agroecosystems of Egypt

Document Type : Original Article

Authors

Nevin Ibrahim ¹
Merha Tawfik ²

¹ Microbiology Department, Faculty of Science, Ain Shams University, Cairo, Egypt

² Plant Protection Department, Desert Research Center, El-Matariya, Cairo, Egypt

10.21608/ejm.2019.17443.1117

Abstract

FUNGAL biocontrol of weed is a promising eco-friendly alternative solution to reduce risks of synthetic herbicides. A field survey conducted in Wadi El-Natroun and North Sinai, Egypt, resulted in the isolation of 36 fungal isolates. Culture filtrates of the obtained isolates were screened for their ability to inhibit the seed germination and seedling development of Portulaca oleracea and Convolvulus arvensis. Filtrates crude extracts of Albifimbria verrucaria MN094460.1 and Cladosporium cladosporioides MN094461.1 gave the highest herbicidal activity against both tested weeds. A. verrucaria caused high reductions in seed germination, shoot and root length, of both weeds. Also, its crude extract significantly reduced seedling fresh weight of P. oleracea (85%) and C. arvensis (59%). On the other hand, C. cladosporioides completely inhibited seed germination, shoot and root length of P. oleracea while its extract caused 78% reduction in seedling fresh weight. In greenhouse, foliar application of 5×107 conidia/ml of A. verrucaria with 0.2% silwet-L-77 significantly reducted P. oleracea chlorophyll a (74%) and fresh weight (82%) also, it reduced C. arvensis chlorophyll b (57%). Whereas, conidial sprays of C. cladosporioides (5×107 conidia/ml with 0.2% silwet-L-77) caused significant reductions in P. oleracea chlorophyll a (73%) and fresh weight (74%). LC-MS/MS analysis revealed the presence of 12 compounds in C. cladosporioides extract and 7 compounds in A. verrucaria extract. This study concluded that A. verrucaria MN094460.1 and C. cladosporioides MN094461.1 are potentially effective biocontrol agents against P. oleracea and C. arvensis. Besides, the herbicidal activity of C. cladosporioides against P. oleracea was reported for the first time.

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