Host-specific interactions between rice, wheat, and multiple Fusarium species

Seedling blight is a major problem in rice and wheat production. Growers often overlook this disease, but it causes significant losses by reducing crop establishment. Many seed- and soil-borne pathogens are responsible for this disease, with several species of the genus Fusarium spp. being among the most common causal agents. While the infection of wheat by Fusarium spp. is well documented, there are only a few reports of Fusarium spp. infection on rice. Some Fusarium spp. are known to have a broad host range, but others are very host specific. In this study, fourteen isolates from eight different Fusarium species were evaluated for their pathogenic ability on rice and wheat and to compare the host specificity of Fusarium spp. on these crops. Several assays were developed to compare rice and wheat seedlings inoculated with Fusarium side by side. Three different media and inoculation methods were assessed: water agar, sandy loam soil, and torpedo sand. Seedlings grown in water agar, and torpedo sand media produced consistent results in several trials. F. graminearum and F. culmorum showed non-host-specific disease infection among rice and wheat seedlings. However, F. fujikuroi and F. proliferatum exhibited host-specific disease development patterns, mostly affecting rice seedlings. In the second chapter, a microscopy characterization of the infection process of Fusarium on rice and wheat was conducted, along with microscopy observations of the effect of Fumonisin on rice. Fumonisin is one of the toxins produced by several fungi, including some species of the Fusarium Fujikuroi Species Complex (FFSC). Rice is often affected by several Fusarium spp. under FFSC. There is a high possibility that the presence of Fumonisin toxin can increase the virulence of Fusarium spp. during disease development. Under bright field microscopy, no tissue penetrating appendages were observed in F. culmorum inoculated rice or wheat roots. However, F. pseudograminearum and F. graminearum isolates extensively grew on rice roots. Appressoria-like structures were observed in the F. pseudograminearum infected root tissues. Additionally, infection pegs, hyphopodia, and foot-shaped structures were noticed in the rice roots infected with F. graminearum. Rice leaves showed very little response to Fumonisin exposure, and no programmed cell death was observed on Fumonisin treated leaves. Overall, this study shows that F. graminearum and F. culmorum have a broad host range and can cause disease in both wheat and rice, while F. fujikuroi and F. proliferatum are only able to cause disease on rice. Preliminary microscopy observations show that F. graminearum penetrates the rice roots at 3-dai. F. pseudograminearum also produces appressoria-like structures at 3-dai. No effect of Fumonisin was observed on rice cells until 72 hours after leaf infiltration.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Crop Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2024

Author dc:creator

• Ahmed, Montasir

Contributors dc:contributor

• Mideros Mora, Santiago X.
• Schroeder, Nathan E.
• Juvik, John A.

• Seedling Blight Disease
• Fusarium Spp.
• Host Specificity

Statement dc:rights

• Copyright 2024 Montasir Ahmed

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/125731

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F125731