الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 96 |  |  |
| | | from | 96 | | |
Abstract
Potato is one of the most important vegetable crops worldwide that consumed almost daily by more than a billion people. Potato crop is infected by many important plant pathogens. Soft rot disease caused by Pectobacteriumcarotovorum subsp. carotovorum (formerly Erwiniacarotovora subsp. carotovora)is considered the most important bacterial disease that causes considerable damage to potato. The present study was carried out to identify biocontrol agents that could be control the pathogen invivo and in vitro.
The pathogen was isolated from infected potato tubers during 2013/2014. Based on the pathogenicity test, one vigor isolate that was able to infect the tubers and caused severe soft rot was chosen for further studies. The pathogen was identified using the physiological and biochemical activities and showed positive reaction for 3% KOH, gelatin liquefication, lipolytic activity, catalase, leavan production, and acid production from mannose, glucose and lactose For confirmation, the pathogen was further identified using 16s rDNAtechnique. Identification confirmed that the bacteria was E. c. subsp. carotovora.
Several Rhizobacterial isolates 98 were screened for biocontrol activities against E. c. subsp. carotovora and resulted in a total of 4 isolates that showed strong antagonistic activities in vitro. Examination of the effectiveness of the 4 isolates on the whole tubers showed the ability of the biocontrol agents to inhibit the pathogen progress on tuber tissues. The four isolates were further identified using the enzyme technology method and 16s rDNA and showed a close similarity with Bacillus subtilis, Sphingobacteriummultivorum,Providencia stuartiiand Pesudomonas. fluorescens
Characterization of the biocontrol agents showed the ability of p. fluorescens and P.stuartiito produce Indole Acetic Acid (IAA). The biocontrol agents showed the abilityB. subtilis, p. fluorescensto producesiderophore and Hydrogen Cyanid. However, the isolate B. subtilis, p. fluorescens, S. multivorum and P.stuartiidid not solubilize phosphate.
The susceptibility of four potato cultivars named Sponta, Cara, Diamond and Monaliz to E.c. subsp. carotovora was examined in vivo. The four cultivars were susceptible to infection with different degrees. Diamont cv. was the most susceptible cultivar than Sponta, Monaliz and Cara Showing an infection reached 83.3%
Application of the four biocontrol agents in vivo showed different levels of inhibitory activities against the pathogen that reached 13.3% the most inhibitory activity was recorded with bacteria P. fluorescens
The aim
1. been holding isolate the bacteria causing the disease samples from infected potato tubers operations
where he collected from different areas of a research station at Suez Canal University / College of Agriculture and Friday market and the large hill in the province of Ismailia.
2. have been identified bacterial isolates in terms of morphology and pigment dye grams and shape of the developing colonies on NA environments, CVPM, PDA, Baladaavh to physiological tests and by enzymes in addition to the definition of isolates by 16srDNA used for defining a bacterium Erwiniacaratovorasubspcaratovora been identified on the 7 isolates of these bacteria.
3. was conducted industrial tests of infection for 7 isolates of the bacteria E. caratovorasubspcaratovora obtained from samples tubers group was grading isolates in their ability pathogenicity and stronger isolation chosen from among the seven isolates to conduct the study by the
4. was conducted to isolate and test some of the microorganisms from the vicinity of the rhizosphere of plants:
where it was 98 bacteria isolated from the roots of the family Solanaceae plants these isolates were tested and know their impact on the colonies of bacteria. Laboratory tests showed the disparity in the ability of bacterial isolates to inhibit bacterial colonies. Was chosen the most powerful four isolates and tested on bacterial isolates to nurse their impact, the results showed that isolates bacterial colonies nurse damper on growth.
5. The definition of bacterial isolates PGPR:
where the four isolates were identified by enzymes in addition to the definition of isolates by 16srDNA The results showed that the bacteria are B. subtilis strain 30L1-2, p. fluorescens, S. multivorum strain BAB-2422, P.vermicola
6. testing four varieties of potato sensitivity:
where we were four varieties of potato sensitivity of the disease mold soft on potato caused by bacteria E.caratovorasubspcaratovora test with determining the damage caused by injury to plant growth so as to reach a resistant varieties or a few injury The results showed that the four varieties are injured but they differed in the degree of response to injury were divided into either a sensitive product (GS) or weak resistance and the resistance of these varieties are (Cara, Diamont, Sponta, Monaliza)
7. Bacteria PGPR test against the bacterium that causes the disease soft mold:
The effect where subtilis B., P. fluorescens, S. multivorum, P.vermicolaagainst soft rot bacteria E. caratovorasubspcaratovora treatment potato crop on the class (Diamont) in the field and compare the flora of plants with bacteria causing rot isolates results showed superiority in improving plant growth as well as the inhibition of bacteria that causes soft rot in potatoes.