الفهرس 
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Abstract
Root-knot nematodes are the most common and destructive nematode pathogens. They produce some of the most dramatic symptoms and can considerably reduce crop yields. Nematicides used to overcome nematode problems they caused more problems in terms of polluting the environment.The new recent advances are to use new approaches for overcome the problem of the pesticides pollution such as the use of green chemistry including plant extracts as one of chemical nematicides alternative.
This work revealed the following results:
5.1 Bioassay study of the tested plant extracts unprepared as nanomaterials against Root-knot nematode M. javanica in vitro:
Effect of plant extracts unprepared as nanomaterials against root-knot nematode M. javanica in vitro in vitro at 100, 50, 25 and 12.5 ul / 50 ml. nematode suspension explained different mortality rates whereas the LC50s recorded to Oleander, Artemisia, Thyme, Ginger , Jojoba, Garlic, Sesbania, Licorice, Uva-ursi, Arugula, Pencil tree, Alhagi, Castor and Lantana were 113.6, 91.4, 107.9, 98.4 , 71.9, 53.6, 94.3, 96.9, 78.0, 91.7, 86.8, 178.5, , 118.6 and 89.8 ul /50 ml, respectively. While the recorded LC90s were1321.4, 827.8, 912.6, 854.4, 937.0, 890.0, 801.0, 712.9, 1071.4, 909.8, 822.8, 2509, , 1291.4 and 923.5ul/ 50 ml, respectively. According to the LC50s we could arrange the superior five extracts in descending order as follows, Garlic, Jojoba, Uva-ursi, Pencil tree and lantana.
5.2 Bioassay study of AgNP prepared with the tested plant extracts against root-knot nematode M. javanica in vitro:
All treatments showed that the increasing of nanoparticles concentration increased the mortality of 2nd J of M. javanica nematode. Bioassay of the efficiency of AgNPs particles with Oleander plant extract against Root-knot nematodes at four concentrations of 100, 50, 25 and 12.5 microliter / 50 ml of nematode suspension. Corrected mortality of the 2nd juveniles of M. javanica caused by using the low and the high concentration ranged between 37.0 to 93.25%, respectively. The slope of the LCP line of AgNPs with oleander extract was positive with the value of 2.06. The LC50 was 15.31 µl /50 ml. of nematode suspension
Mortality of Root-knot nematode J2 exposed to AgNP mediated by Artemisia extracts ranged between 44.68 to 80.85% with the low and high concentrations 12.5 and 100 ul./50 ml nematode suspension, respectively. LCP line slope was1.119 and the LC50 was 15.73ul./ 50 ml. of nematode suspension.
The preparation of AgNPs with extract of Thyme plant against Root-knot nematodes, M. javanica caused mortality ranged between 43.93 and 76.17 with the concentration of 12.5 and 100 microliter/ 50 ml of nematode suspension. The estimated slope of this preparation was 0.984. The LC50 was 14.79 µl /50 ml. of nematode suspension.
The effect of Ginger in vitro against Root-knot nematodes, M. javanica that caused mortality ranged between 49.57 and 91.84 with the concentration of 12.5 and 100 microliter/ 50 ml of nematode suspension. The estimated slope of this preparation was 1.45.. The LC50 was nearest to the LC50 of arugula recording 14.12 µl /50 ml. of nematode suspension.
The preparation of AgNPs particles with extract of Jojoba plant against Root-knot nematodes, M. javanica caused mortality ranged between 59.55 and 95.84 with the concentration of 12.5 and 100 microliter/ 50 ml of nematode suspension. The estimated slope of this preparation was 1.74.. The LC50 was 10.24 µl /50 ml. of nematode suspension.
Bioassay of the efficiency of AgNPs particles with Garlic plant extract against Root-knot nematodes was tested at the concentration of 100, 50, 25 and 12.5 microliter / 50 ml of nematode suspension. Corrected mortality of the 2nd juveniles of M. javanica caused by using the low and the high concentration ranged between 57.02 to 90.42%, respectively. The slope of the LCP line of AgNo3 nano-particles with Garlic extract was positive with the value of 1.19. The LC50 was 9.54 µl /50 ml. of nematode suspension
The Silver nanoparticles synthesized by Sesbania gave mortality ranged between 14.3 to 91.0 % with the concentrations of 12.5 and 100 microliter/ 50 ml nematode suspension, respectively. The estimated slope of this material was 2.69. The LC50 was 37.71µl /50 ml. of nematode suspension as shown in Table (21) & Fig. (22).
The Silver nanoparticles synthesized by Licorice gave mortality ranged between 48.51 to 72.34% with the concentrations of 12.5 and 100 microliter/ 50 ml nematode suspension, respectively. The estimated slope of this material was 0.6838. The LC50 was 15.76 µl /50 ml. of nematode suspension.
Silver nanoparticles synthesized by Uva-ursi gave mortality ranged between 57.44 to 96.38 % with the concentrations of 12.5 and 100 microliter/ 50 ml nematode suspension, respectively. The estimated slope of this preparation of uva-ursi was 1.86. The LC50 was 10.89 µl /50 ml. of nematode suspension.
The corrected mortality of M. javanica exposed to AgNo3 nano-particles synthesized by Arugula was less than garlic recording 86.8 and 49.25 % with the high and the low concentrations, 100 and 12.5 microliter, respectively. Slope of the LCP line by using Silver nanoparticles synthesized by Arugula was positive with slope value of 1.22 . The LC50 was 16.25 µl /50 ml. of nematode suspension
The preparation of AgNPs with extract of Pencil tree gave mortality ranged between 52.0 to 92.0 % with the concentrations of 12.5 and 100 microliter/ 50 ml nematode suspension, respectively. The estimated slope of this preparation of ginger was 1.45. The LC50 was 11.11 µl /50 ml. of nematode suspension
Silver nanoparticles synthesized by Alhagi extract gave less mortality ranged between 38.29 to 68.72 % with the concentrations of 12.5 and 100 microliter/ 50 ml nematode suspension, respectively. The estimated slope of this preparation of Alhagi was 0.88. The LC50 was 26.43 µl /50 ml. of nematode suspension.
The corrected mortality of M. javanica exposed to AgNP synthesized by Castor was slightly less than oleander recording 91.33 and 34.30% with the high and the low concentrations, 100 and 12.5 microliter, respectively. Slope of the LCP line by using Silver nanoparticles synthesized by Castor was positive with slope value of 1.92. The LC50 was 18.72 µl /50 ml. of nematode suspension
AgNP prepared by Lantana extract caused mortality to root- knot nematode J2 ranged between 52.76 to 85.42% at 12.5 and 100 ul. 50ml. suspension, with slope of LCP line 1.0324 and LC50 11.74ul. / 50ml. of nematode suspension. Testing of AgNPs particles prepared chemically against Root-knot nematodes, M. javanica caused mortality ranged between 40.80 and 82.00 with the concentration of 12.5 and 100 microliter/ 50 ml of nematode suspension. The estimated slope of this preparation was 1.29. The LC50 was 18.88 µl /50 ml. of nematode suspension
The effect of Chitosan prepared in nano phase on Root-Knot nematodes. This preparation caused mortality ranged between 72.34 to 96.8 % at the low and high concentrations 12.5 and 100 µl / 50 ml of nematode suspension and the LCP line slope was1.40. The LC50 was 5.16 µl /50 ml. of nematode suspension.
The estimated toxicity indices could be divided to three categories as follows:-
The high toxicity indices of the tested materials were chitosan (100%) followed in descending order by AgNP botanically prepared by the extracts of Garlic, Jojoba, Uva-ursi, Pencil tree and Lantana recording 54.0, 50.4, 47.4, 46.6 and 43.9%, respectively. The moderate toxicity in descending order were AgNP prepared by ginger, Thyme, Oleander, Artemisia, Licorice and Arugula recording 36.5, 34.7, 33.7, 32.8,32.7 and 31.8, respectively
The low toxicity in descending order were AgNP prepared by Castor, AgNP prepared chemically, AgNP prepared by Alhagi and Sesbania recording 27.6, 27.3, 19.5 and 13.7, respectively
5.3. Potentiation effect of using AgNPs synthesized by different plant extracts on plant extracts used alone:
Potentiation rates indicate that the high potentiation rate was with AgNP prepared by Pencil tree recording (7.8) followed by other mediated with Lantana (7.6). Less potentiation rate was 2.5 with Sesbania. AgNP mediated by other extracts the potentiation rates ranged between 5.6 and
5.4. characterization of Silver Nanoparticles (Visual observations)
UV-Vis spectra analysis was indicated that the curve of the absorbance of the nanoparticles synthesized by oleander behaved in the same trend with ginger whereas the 1st peak was 1.863 (a.u.) and realized by wave length of 450 nm with oleander and as for ginger preparation the 1st peak was 1.902 with the same wave length. The 2nd peak with oleander and ginger recorded 1.93 and 1.889 (a.u.) at the wave length 600. Artemisia and Jojoba behaved similarity in uv-vis spectra analysis whereas the 1st peaks of these AgNP preparations absorbance were at 430 nm., recording 1.596 and 1.087 and the 2nd peak was with wavelength 650 nm., recording 0.914 and 0.676 (a. u.), respectively. AgNP with thyme gave one peak (1.904) of absorption with the wave length 450nm.
AgNP prepared chemically recorded one peak of absorption (0.600) at the wave length 200 nm. On the other hand the peak of absorption (0.600) with chitosan also was at wave length 200 nm.
The curves of UV-Vis spectra analysis of AgNP synthesized by Garlic, Sesbania, Licorice, Uva-ursi. On the other hand the UV-Vis spectra of AgNP mediated by Arugula, Pencil tree and Alhagi, Castor and Lantana illustrated in Figure 32 C. All peaks of these preparations were realized at wave length 450 nm. recording absorbance units of 1.903, 1.258,1.618, 1.859, 0.712, 1.151, 1.087, 0.711 and 1.889, respectively.
5.5. Effect of different plant extracts without AgNPs formulation on root knot nematode infecting tomato and the growth parameter in the green house (in vivo)
The effect of plant extracts differed in their potential against nematode reproduction as well as the growth of tomato inoculated by M. javanica under greenhouse conditions. Recduction of M .javanica over control ranged between 27.2 to 74.2 for Sesbania and Garlic, respectively. As for reproduction rate ranged from 3.20 to 9.03 with Garlic and Sesbania, respectively opposite to 12.40 with control. Growth of tomato infected by M. javanica improved by the treatments by different plant extracts. Good growth parameters represented by fresh shoot length leaflets were realized with Garlic, Pencil tree, Arugula, Uva-ursi and Jojoba recording shoot lengths, 47.5, 45.0, 41.6, 41.25 and 41.0, respectively. Numerous leaflets appeared with the treatment with Oleander, Garlic, Jojoba, Uva-ursi and Pencil trees recording 61.5, 61.0, 55.80, 47.5 and 47.5 leaflets, respectively.
5.6. Effect of the AgNP synthetized by different plant extracts on root knot nematode infecting tomato and the growth parameter in the green house (in vivo)
The reproduction of M. javanica inoculated tomato seedlings under greenhouse conditions varied with the different treatments of botanical AgNP according to the type of plant extracts consist the AgNP formation. Chitosan absolutely surpassed other botanical and chemical AgNP in reducing M. javanica population recording 85.1% of reduction over control and reproduction rate of 1.85. The arrangement of AgNP synthesized by plant extracts in reducing M. javanica population over control in descending order up to 70% should be Licorice, Garlic, Lantana, Jojoba, Arugula, Pencil tree and Oleander recording reduction percentages of 82.8, 80.0, 78.5, 77.6, 77.1, 74.8 and 70.6 %, respectively. We could arrange these preparations according to reproduction rates of M. javanica as follows Garlic, Lantana, Jojoba, Arugula, Licorice, Uva-ursi, Pencil tree and Oleander recording 2.48, 2.69, 2.78, 2.84, 2.95, 3.09, 3.12 and 3.64. Galling indices ranged between 2 and 4. Gall index 2 was estimated with Chitosan, AgNP synthesized by Garlic, Pencil tree and Licorice. Gall index 3 estimated with Arugula, Lantana, Uva-Ursi, chemical AgNP, Jojoba and Oleander. Other preparation gave galling index 4 while control treatment recorded gall index 5. Vegetation growth obviously improved with different treatments in comparison with the control (infected plants with M. javanica).The six highest fresh shoot lengths were observed with the treatment by AgNP synthesized by Garlic, Pencil tree, Arugula, Uva-ursi, Jojoba and Licorice recording 49.5,48.0,45.6, 44.25, 44.0 and 42.cm., respectively in comparison with the control infected plants (24.25 cm.) . The most Numerous leaflets occurred with the treatments of AgNP prepared by Ginger, Oleander, Jojoba, Uva –ursi and Pencil tree, and Licorice recording 65.00, 64.5, 61.8, 52.5, 51.5, and 48.75, respectively in comparison to 21.25 for the control (infected plants) .
5.7 Comparison between the plant extracts unformulated as nanoparticles and other formulated with AgNP:
All treatments by AgNP formulated with different plant extracts surpassed other plant extracts unformulated as nonparticles in reducing the reproduction rate (Rep.) of M. javanica under greenhouse conditions. The five best advanced AgNps which prepared with Sesabania, Artemisia, Al Haagi, Ginger, Thyme, Castor and Uva Ursi gaving R.% 91.9, 90.9, 89, 88, 87,84.5 and 81.3 respectively.