P-267 - QTLs Associated with Defense-Primed Resistance to Bacterial Panicle Blight

Monday, August 4, 2025

3:45 PM - 4:30 PM HST

Location: Exhibit Hall 3

Author(s)

JC

Jose Cortes

Postdoctoral Research Associate
Louisiana State University
Baton Rouge, Louisiana, United States
JO

John Ontoy

Postdoctoral Research Associate
Clemson University
Baton Rouge, Louisiana, United States
AA

Ashmita Acharya

Graduate Research Assstant
Louisiana State University
Baton Rouge, Louisiana, United States

Presenting Author(s)

JB

Jobelle Bruno (she/her/hers)

Graduate Research Assistant
Louisiana State University
Baton Rouge, Louisiana, United States

Author(s)

JH

Jong Hyun Ham

Professor
Louisiana State University Agricultural Center
Baton Rouge, Louisiana, United States

Abstract Text: Bacterial panicle blight (BPB), caused by Burkholderia glumae, has emerged as an important rice disease in tropical and semi-tropical regions, leading to reduce grain quality and yield. Culturing disease resistant varieties is a crucial disease management strategy for BPB. Recently, we found that seed-priming using biological agent A257 effectively suppressed BPB and other major rice diseases. To understand the genetic background of rice resistance to BPB induced by seed-priming with A257, a recombinant inbred line (RIL) population consisting of 164 lines was developed by crossing the moderately resistance medium-grain Jupiter with the susceptible variety Bengal. The RIL population was treated with A257 and evaluated in three replications in the field. Following inoculation with the virulent B. glumae strain 336gr-1, phenotypic evaluation was conducted using a 0-9 disease severity scale. QTL analysis identified two minor QTLs in 2021: one on chromosome 1 (qTBPB1.1) and another one on chromosome 4 (qTBPB4.1), which explained 4.88 % and 9.25 % of phenotypic variance (PVE), respectively. From an additional trial in 2023, a major QTL was identified on chromosome 4 (qTBPB4.2), with an 11.27% PVE. This QTL overlapped with qBPB4.2, which was previously identified with 5.52 % PVE from a trial using the same population but without seed-priming. These results suggest the genomic region around qTBPB4.1 and qTBPB4.2 are associated with BPB resistance enhanced through seed-priming with A257.