الفهرس 
Chapter (1): INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
This study was carried out under laboratory and greenhouse conditions at Faculty of Agriculture, Menoufia University, Shibin EI-Kom, during the period from 2008-2013 to investigate:
1- Survey of root-knot nematodes Meloidogyne spp. in various crops and locations.
2- Isolation of fungal and bacterial bio-control agents and screening of their effectiveness against root-knot nematodes
3- Study the mechanism of the effective bio-control agents.
4-Evaluation of some plant extracts against root-knot nematodes and studying the mechanism of their effectiveness to control root-knot nematode.
Results obtained from the present investigation could be summarized as follows:
1- Root-knot nematodes, Meloidogyne spp. are found associated with the economic vegetable, fruit and field crops at different locations in Behira and Menoufiya governorates. The frequency of occurrence of root-knot nematodes Meloidogyne spp. was 100, 75- 100 and 60 - 100 % in Kom Hamada, El-Nubaria and Shebin El-Kom, respectively.
2- The highest population density of root-knot nematode second stage juveniles /100 cmP3P soil was found in squash, horse bean and cucumber by 711, 990 and 500 second stage juveniles /100 cmP3P soil respectively at Kom Hamada, El-Nubaria and Shebin El-Kom.
3- Common lambsquarters, small bindweed, common purslane and solanum were among the most important host weeds of root-knot nematodes at Shebin El-Kom, El-Nubaria and Kom Hamada regions.
4- The nematophagous fungus Arthrobotrys oligospora was isolated from potato plants rhizosphere. The fungus was morphologically and molecularly identified using PCR and DNA Sequencing.
5- The nematophagous fungus A. oligospora was effective in increasing the root-knot nematode M. incognita mortality under laboratory conditions.
6- Arthrobotrys oligospora was effective in reducing the root-knot nematode parameters and increasing plant growth parameters of tomato plants under greenhouse conditions.
7- The mechanism of Arthrobotrys oligospora to control root-knot nematode is due to forming three dimension adhesive net work trapping organs.
8- Ten isolates of endophytic bacteria were isolated from stems and roots of healthy tomato and potato plants and molecularly identified using PCR and Sequencing methods.
9- Culture filtrates of all bacterial isolates reduced egg hatching of M. incognita in vitro. The greatest egg hatching inhibition was recorded with B. thuringinsis followed by B. cereus while the least one was Paracoccus sp.
10- All tested bacterial isolates culture filtrates of increased M. incognita larvae mortality in vitro. The greatest inhibition of larvae mortality was recorded with B. thuringinsis as recorded the highest number of inactive larvae, followed by B. cereus, while the least one was Paracoccus sp.
11- The Application of bacterial isolates culture filtrates using three methods i.e. root dipping, soil drench or combination of both were effective in reducing the penetration rate of M. incognita juveniles after 15 days of nematode inoculation into tomato seedling roots.
Bacillus thuringinsis showed the highest effect followed by B. cereus, while the least one was Paracoccus sp. at all application methods.
12- All bacterial isolates were effective in reducing reproduction of M. incognita on tomato plants under greenhouse conditions. The highest effect was occurred by B. thuringinsis, followed by B. cereus, while the least one was Paracoccus sp. when combination method was applied.
13- Application of bacterial isolates culture filtrate was effective in enhancing tomato plant growth parameters. Bacillus thuringinsis was the most effective one, followed by B. cereus, while the least one was Paracoccus sp. when combination method was applied.
14- The mechanism of bacterial isolates to control root-knot nematode may be due to the positive activities of indole acetic acid (IAA) production, phosphate solubilization, Pectinase activity and Cellulase activity.
15- Infrared and Gas chromatography analysis of the different Plants extract showed presence of different chemical components and functional groups such as alkanes, amides, amines, aromatics aliphatic amines, alkyl halides.
16-All used plant extracts using reduced M. incognita egg hatching in-vitro. Results showed that ethanol extract of oleander, methanol extract of marjoram and petroleum ether extract of datura were the most effective extracts.
17-All tested plant extracts increased the larvae mortality of M. incognita in vitro. The greatest larvae mortality was recorded with the use of petroleum ether extract of oleander, chloroform extract of marjoram and datura petroleum ether extract.