Genetic Variation and Biological Control of Fusarium graminearum Isolated from Wheat in Assiut-Egypt

Abstract

Fusarium graminearum Schwabe causes Fusarium head blight (FHB), a devastating disease that leads to extensive yield and quality loss of wheat and other cereal crops. Twelve isolates of F. graminearum were collected from naturally infected spikes of wheat from Assiut Egypt. These isolates were compared using SRAP. The results indicated distinct genetic groups exist within F. graminearum, and demonstrated that these groups have different biological properties, especially with respect to their pathogenicity on wheat. There were biologically significant differences between the groups; with group (B) isolates being more aggressive towards wheat than groups (A) and (C). Furthermore, Trichoderma harzianum (Rifai) and Bacillus subtilis (Ehrenberg) which isolated from wheat kernels were screened for antagonistic activity against F. graminearum. They significantly reduced the growth of F. graminearum colonies in culture. In order to gain insight into biological control effect in situ, highly antagonistic isolates of T. harzianum and B. subtilis were selected, based on their in vitro effectiveness, for greenhouse test. It was revealed that T. harzianum and B. subtilis significantly reduced FHB severity. The obtained results indicated that T. harzianum and B. subtilis are very effective biocontrol agents that offer potential benefit in FHB and should be harnessed for further biocontrol applications. The accurate analysis of genetic variation and studies of population structures have significant implications for understanding the genetic traits and disease control programs in wheat. This is the first known report of the distribution and genetic variation of F. graminearum on wheat spikes in Assiut Egypt.

Biochemical changes in ears of wheat genotypes subjected to Fusarium spp. attack

“…Such differences in the resistance reaction of FHB-resistant, wheat genotypes could be ascribed to different biological properties of the Fusarium races. It was shown that aggressiveness of F. graminearum isolates showed a high level of genetic variations even in samples that were growing at same field location [19].…”

The Mode of Action of Bacillus Species against Fusarium graminearum, Tools for Investigation, and Future Prospects

“…This filamentous ascomycete infects floral tissues of cereal plants and contaminates food grains [7]. Infection is associated with premature bleaching symptoms, which mainly reduce grain quality and, less often, yield [3,7,8,9].…”

Bacterias endófitas de Capsicum frutescens antagónicas a Fusarium spp.

“…Sobre Fusarium, Mahmoud (2016) comprobó la acción inhibitoria de cepas silvestres de B. subtilis, aisladas de granos de trigo, sobre el crecimiento de diferentes cepas patógenas de Fusarium graminearum productoras de la fusariosis de la espiga. La acción antagónica de B. subtilis sobre F. graminearum fue significativa, al igual que la reducción de la fusariosis de la espiga en cultivo in vitro en invernadero (Mahmoud, 2016). Asimismo, Tejera-Hernández et al (2011) destacaron el gran potencial de B. subtilis, como inhibidor de Fusarium oxysporum, debido a la producción lipasas, proteasas y β-glucanasas y quitinasas (Tejera-Hernández et al, 2011).…”