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Root-knot nematodes (Meloidogyne spp.) have been reported to be responsible for large economic losses of agricultural crops due to their wide host range and variety of suitable climates. The control measures of these parasitic nematodes depend upon synthetic nematicides and a small number bio-based products. Chemical nematicides are eliciting adverse effects on the environment and human health. In the present study, an alternative tool, nano-chitosan was tested for the control the root-knot nematodes, Meloidogyne incognita, and Tobacco mosaic tobamovirus (TMV) in greenhouse-cultivated tomato. The effect of nano-chitosan on morphological (weight and length of shoot and root systems) and biochemical responses (Polyphenol oxidase, Peroxides, Total soluble phenol and Total protein) was assessed. The obtained results indicated that densities of Meloidogyne incognita alone or in the presence of TMV were decreased by nano-chitosan at a range of 45.89 to 66.61%, while root gall desntiy was reduced between 10.63 and 67.87%. Moreover, the density of TMV on tomato leaves singly or in the presence of M. incognita was suppressed at range of 10.26 to 65.00% after 20 days of infection, and reached up to 58.00% after 40 days of infection. However, soil application of nano-chitosan pre infection reduced TMV density only by 5.48%. Morphogenesis of tomato plants such as shoot and root systems were significantly improved. The impacts of nano-Chitosan applications on total soluble phenol, total protein, polyphenol oxidase and peroxides after 20 and 40 days of infections varied.

For many years, chemical pesticides have been performed to control different pests and diseases and this may be due to their broad spectrum of action, easy of application and the relatively low cost. But these chemicals have environmental risks, thus alternative control agents are needed. Chitosan is one of the novel suggested solutions to reduce the economic losses associated with chemical pesticides. Chitosan is naturally-occurring compound, as well as safe and biodegradable which obtained from certain natural sources. Chitosan have unique properties which help to control viruses, bacteria, fungi, insects, plant nematodes and other pests locally and systemically.

Cucumber mosaic cucumovirus (CMV) was isolated from naturally infected Cowpea plants (Vigna unguiculata L.) showing different symptoms of mosaic; mottle, dwarfing, and vein clearing, grown at certain locations of Alexandria governorate, Egypt, during the growing seasons from 2011-2012. CMV isolate was transmitted by Aphid nerii, A. gossypii, and Myzus persicae in non-persistent manner. The virus was partially purified using polyethylene glycol (PEG) 6000, and differential centrifugation. The ratio of A 260/280 was 1.622 and A 280/260 was 0.617. Whereas, the ratio of A max/ min was 1.915. Concentration of the virus in the preparation was estimated using an extinction coefficient of E 2600.1% = 5. Yield of purified virus was about 6.88 mg/ 100g fresh weight of leaves of Nicotiana glauca. Antiserum titer was determined by Indirect enzyme linked immunosorbent assay (ELISA). Positive ELISA values were obtained up to dilutions of 1: 25600. The virus was detected by indirect ELISA in infected sap at 8, 16 and 24 days after inoculation; and by Tissue blot immunoassay (TBIA) on nitrocellulose membrane after the same period. The unused face of the processed nitrocellulose membrane already printed with plant tissues was tested. Results revealed that both faces of nitrocellulose membrane and Canson paper could be used as solid carriers in TBIA, for detection of CMV in infected leaves. According to Reverse transcription polymerase chain reaction (RT-PCR); the size of amplification of the obtained product was approximately 870 bp for CMV isolate; and was assigned accession number of LN606587. The Phylogenetic tree was generated using partial sequence of CMV isolate, with those of other CMV isolates obtained from GenBank. The aims of the current work were; to produce specific polyclonal antiserum against the purified CMV isolated from cowpea plants, and to register this isolate in GenBank.

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