Comparative Study Between the Effects of the Synthetic Fungicide Mancozeb and the Biological Fungicide Plant Quard on Allium cepa plant

Pesticides constitute a heterogeneous category of chemical specifically designed for the control of plant diseases. Pests cause annually a drastic loss of the economical crops allover the world. The wide production and use of chemical pesticides causes a serious pollution to the surrounding environment. These chemicals, a part from affecting the target pest, also affect economical plants, animals and human. Many investigators studied the mutagenic potentialities of pesticides using different systems (Njagi and Goplan, 1981; Datta et al., 1995; Barakat, 1997; Biscardi et al., 2003; Bolognesi, 2003; Dane and Dalgic, 2005; Kaymak and Muranli, 2005; Singh, 2007). Higher plants provide valuable genetic assay systems for screening and monitoring of genotoxic agents and have recognized as excellent indicators of mutagenic effects (Grant and Owens, 2002 and 2006). Allium cepa and Vicia faba chromosomal aberration bioassay is an efficient and reliable short-term bioassay for the rapid screening of chemicals for clastogencity (Ma, 1982; Grant 1982 &1994; Kanaya et al., 1994; Abdel Migid et al., 2007). Man today is concerned very much with the pollution of his environment. The field of environmental mutagenesis still needs more efforts in order to evaluate many thousands of pollutants that are released every day in our environment. Biological control agents for plant disease are currently being examined as alternative to synthetic pesticides due to their perceived increased level of safety and minimal environmental impacts. Species of Trichoderma and Bacillus subtilis have been used as effective biological control agents against some diseases. Trichoderma are commercially applied as biological control agents based on the production of some metabolites such as trichothecin, nonanoic acid and the enzyme α-1,3 or 1-6 glucanase (Antonia-Gallo et al., 2004; Madhu-Aneja et al., 2005; Montero et al., 2005; Sanz et al., 2005). Also, a cyclic lipopeptide compound (iturin A) produced by Bacillus subtilis has strong antifungal properties and low mammalian toxicity (Klich, et al., 1994; Nagorska et al., 2007). The present investigation was planned to compare the effect of the synthetic fungicide mancozeb with the biological fungicide plant guard on the mitotic activity and percentage of different parameters of the cell cycle in root tips of Allium cepa. Also, the capacity of these fungicides to induce chromosomal aberration and change in seed protein electrophoretic profiles were investigated.