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Abstract wit P1v Experiment a .we UMMARY conducted utlder laboratory condctian Dept. and und ez field eriment station of the Faculty ces, Moshtohor, Zagazig University. Soil samples f m Al-Amar village were used in these were taken from field which ”Was not -144- itions in the of throw,hout; the last 15 years. an atomizer. xperiments. soil samples were treated ratesoflO.2O,40.60,BO and 100 ppm. dried soils were used for every expe equivalent concentration of inseotcide acetone and the solution was sprayed soil was left for 24 hr.to nian bulbs equal in diamet er and weight e treated soil. The effects on root, ent and flowering of the plants were totoxic s,y.mptomswere recorded and :Porlaboratory inseoticides a kilograms of’ nt replioate. us get rid of acetone. wer cultivated in g~e leaves develo reo rded. Also the Pho ographed. -------- - ._-_.- suspens ions of chlrodane, endrin, mepllospholan , thomyl and fenv lerate and colchicine were tested water solution at concentrations, 10,20,40,60,80 ioine solution was used as control. ul.bs fro. the s e variety, diamet er, and weight were llowed to. The number, length and the dry weiht of the sprou ed roots were estirna~ed. -145- Cross in the treated sprouted roots were de after root lling and fixation. The stained cross sections were t study the side effect of these pesticides on t e cell content. Cytologica and cytogenetic effect s were also studied to showth 1r effects on mitotic index and mitotio abnormalities. aJ.. studie s were carried out to study the omeinsecticides on the IlliA and DNA s.rnthesis in 0 ion root cells • H1stoch Experimen s were oonducted also under field conditione to study the effect of these pesticides on crop -147- at all concentrations exoept 10 ppm in the first and 10, and 100 ppm. in oase of the seoond insecticide. Chlordane had nearly no effect. 4- Chlordane, fenvalerate and endrin decreased the numbers of root s sprouting four days aft e1’treatment. The percentage of decrease increased with increasing the concentrations. The other tested insecticides varied in their effect. - Chlordane and endrin decreased the dry weight of roota, while mephosfolan was somewhat less effective. Kethomwl increased the dry weight of the roots at concentrations tested except 100 ppm. Fenvalerate creased also the dry weight except at concentrations o and 20 ppn. - In the caae of colchicine treatment, tumours appeared at 2 to 3 mm., from the tips of the roots, While in the CBse of insecticides, tumours formations- appeared in two differ811t structures; tWDOuroua throughout and terminal tumours. -148- 7 Microscopic examination of transverse sections of treated onion root tips indicated that chlordane at the rates more than 40 ppm. sli.ghtJ.ydamage the pith layer forming a little gap. Most of the epidermis cells were distroyed. Mephosfolan damaged the vascular cylinder at all concentrations. The piliferous layer was also damaged. Methomyldestroyed the cortex layer and the pith layers. The following symptoms were clear in the csse of fenvalerate, the dc;::truction of both epiderm and cortex layer, bypertorophy and gaps in the root tissues. _ Result indicated that all the insecticides at the different concentrations decreased the mitotic index. _ The different abnormalities which were observed were, sticky’ohromosomes, fragment J briedge, break and gap. Also distributive o~ movement abnormalities were lagging chromosomes, polidy which included diploidy or polyploiQy, multinuclate cells which included bi,tri and tetranuclus, and a-metaphase or distrubed cell. -149- 10- All insecticides tested decreased RNAand DNA content. 11- Dimethoate, Triazophos, ,cypermethrin and e.ldicarb decreased the crop yield of broad bean, while endrin had Ilearly no effeot. Endrin, mephosfolan, profenfos, methomyl.and fenvalerate increased the cotton yiel.d. |