In: Sydowia 77, (2025): 53-67; ISSN 0082-0598, DOI 10.12905/0380.sydowia77-2025-0053, Published online on August 5, 2024

Genetic diversity of Bipolaris spp., the causal agent of rice brown spot: the application of ISSR-based molecular markers

Mohammad Reza Safari Motlagh,*, Lobna Hajji-Hedfi*, Mehdi Khosravi Moghadam, Ali Akbar Ebadi & Ahmed M. Abdel-Azeem

1 Department of Plant Pathology, Faculty of Agriculture, Rasht Branch, Islamic Azad University, Guilan Province, Iran
2 Regional Centre of Agricultural Research of Sidi Bouzid, CRRA, Gafsa Road Km 6, B.P. 357, 9100, Sidi Bouzid, Tunisia
3 Department of Plant Pathology, Faculty of Agriculture, Science and Research Branch, Islamic Azad University,
Tehran province, Iran
4 Department of Plant Breeding and Biotechnology, Faculty of Agriculture, Rice Research Institute of Iran, Rasht, Iran
5 Department of Botany and Microbiology, Faculty of Science, University of Suez Canal, Ismailia City, 41522, Egypt
* e-mails: ssafarimotlagh@yahoo.com; elhajjilobna@yahoo.fr

Safari Motlagh M.R., Hajji-Hedfi L., Khosravi Moghadam M., Akbar Ebadi A. & Abdel-Azeem A.M. (2024) Genetic diversity
of Bipolaris spp., the causal agent of rice brown spot: the application of ISSR-based molecular markers. – Sydowia 77: 53–67.

The brown spot disease of rice caused by Bipolaris spp. is one of the most important seed-borne diseases of rice in the world.
Adequate awareness of pathogens’ genetic structure is highly important for selecting a proper strategy for their control. This research
aimed to investigate the genetic diversity of the Bipolaris spp. fungal isolates using the ISSR marker. This study was
conducted in Guilan province in Iran for the first time. In this research, a total of 31 fungal isolates of Bipolaris spp. were isolated
from rice samples collected from Guilan province and the genetic diversity of B. victoriae was explored by inter simple
sequence repeat (ISSR)-based molecular markers. It was found that the species B. victoriae had 97 % frequency and accordingly,
80 bands were obtained out of which 77 gene loci showed polymorphism. ISSR14 with 18 bands and ISSR12 with 14 bands had
the highest and lowest number of amplified fragments, respectively. Based on the results, the isolates were classified into four
groups in terms of the total number of polymorphic bands of ISSR. The highest genetic diversities were observed in the two
groups of leaf and panicle. The results of the genetic diversity of the isolates showed high intra-population diversity. The DNA
band patterns could not show a direct correlation between polymorphism and geographical regions. The results revealed high
intra-population genetic diversity. Therefore, it is of crucial importance to cultivate resistant cultivars consistent with this diversity
in the study location.

Keywords: brown spot disease, ISSR.