Biological control of Fusarium wilt in tomato by endophytic rhizobactria

Abstract

The Fusarium Wilt disease that is caused by Fusarium oxosporium is considered one of the most important diseases that threatens the agricultural production of tomato. In this study, the isolation of 52 Enterobacter strains that were isolated from the roots of healthy tomato plants in fields also containing tomato plants infected with the Fusarium Wilt disease were present. These Enterobacter strains were diagnosed by two methods: Api Kit 20E and biochemical test. In this study the antagonism of these isolated Enterobacter strains against the etiological agent for Fusarium Wilt disease were tested in vitro. The recent study of antagonism against Fusarium oxosporium showed that there are only two species strains out of 52 have antagonism against Fusarium oxosporium, and these strains are: Pseudomonas flourscence, and Basillus subtilis.However these three isolated strains have antagonism against growth of Fusarium oxosporium and the inhibition zone ranged from (1.5 to 11 ml). The selected isolates were evaluated in vitro for their activities related to plant nutrition and plant growth regulation. Both of these assessed endophytes were found to exhibit capabilities in ammonia and indole acetic acid (IAA) production as well as phosphate solubilization. It is concluded that application of Pseudomonas flourscence and Basillus subtilis may be promising approach for biological control of the tomato bacterial wilt and may play an important role in sustainable agriculture.