# Association between molecular markers and resistance to bacterial blight using binary logistic analysis

## TL;DR

This study identifies molecular markers and genes linked to resistance in wheat against bacterial blight, helping improve breeding strategies.

## Contribution

The study discovers specific ISSR markers and genes associated with bacterial blight resistance in wheat cultivars.

## Key findings

- Three superoxide dismutase-related genes linked to resistance were identified using ISSR primers F3, F5, and F12.
- Cultivars Qods, Omid, and Atrak showed resistance to bacterial blight.
- Seven susceptibility-associated genes were also identified.

## Abstract

The most effective strategy for managing wheat bacterial blight caused by Pseudomonas syringae pv. syringae is believed to be the use of resistant cultivars. Researching the correlation between molecular markers and stress resistance can expedite the plant breeding process. The current study aims to evaluate the response of 27 bread wheat cultivars to bacterial blight disease in order to identify resistant and susceptible cultivars and to pinpoint ISSR molecular markers associated with bacterial blight resistance genes. ISSR markers are recommended for assessing a plant's disease resistance. This experiment is focused on identifying ISSR molecular markers linked to bacterial blight resistance. After applying the bacterial solution to the leaves, we performed sampling to determine the infection percentage in the leaves at different intervals (7, 14, and 18 days after spraying). In most cultivars, the average leaf infection percentage decreased 18 days after spraying on young leaves. However, in some cultivars such as Niknegad, Darab2, and Zarin, leaf infection increased in older leaves and reached up to 100% necrosis. In our study, 12 ISSR primers generated a total of 170 bands, with 156 being polymorphic. The primers F10 and F5 showed the highest polymorphism, while the F7 primer exhibited the lowest polymorphism. Cluster analysis grouped these cultivars into four categories. The resistant group included Qods, Omid, and Atrak cultivars, while the semi-resistant and susceptible groups comprised the rest of the cultivars. Through binary logistic analysis, we identified three Super oxide dismutase-related genes that contribute to plant resistance to bacterial blight. These genes were linked to the F3, F5, and F12 primers in regions I (1500 bp), T (1000 bp), and G (850 bp), respectively. We also identified seven susceptibility-associated genes. Atrak, Omid, and Qods cultivars exhibited resistance against bacterial blight, and three genes associated with this resistance were linked to the F3, F5, and F12 primers. These markers can be used for screening or transferring tolerance to other wheat cultivars in breeding programs.