Molecular Marker-Based Identification of Resistance to Bipolaris sorokiniana in Kazakh and Global Wheat Germplasm
by
, , , , , , , , , , , and
Ardak Bolatbekova
1,2,*,
Alma Kokhmetova
1,*,
Yerlan Dutbayev
1,2,
Göksel Özer
3
,
Madina Kumarbayeva
1,
Sholpan Bastaubayeva
4,
Aidana Kharipzhanova
1
,
Makpal Nurzhuma
1,
Zhenis Keishilov
1,2,
Assiya Kokhmetova
1,
Kanat Bakhytuly
1,
Kanat Mukhametzhanov
1 and
Vladimir Tsygankov
5 1
Department of Genetics and Breeding, Institute of Plant Biology and Biotechnology, Almaty 050040, Kazakhstan
2
Faculty of Agrobiology, Kazakh National Agrarian Research University, Almaty 050010, Kazakhstan
3
Department of Plant Protection, Faculty of Agriculture, Bolu Abant Izzet Baysal University, Bolu 14030, Turkey
4
Kazakh Research Institute of Agriculture and Plant Growing, Almalybak 040909, Kazakhstan
5
Kazakh Research Institute of Horse Breeding and Forage Production, Aktobe 030014, Kazakhstan
*
Authors to whom correspondence should be addressed.
Biology 2026, 15(3), 244; https://doi.org/10.3390/biology15030244
Submission received: 22 November 2025
/
Revised: 20 January 2026
/
Accepted: 23 January 2026
/
Published: 28 January 2026
(This article belongs to the Special Issue The Potential of Genetics and Plant Breeding in Crop Improvement)
Simple Summary
In arid and semi-arid regions, including Kazakhstan, wheat production is severely constrained by diseases caused by Bipolaris sorokiniana. This pathogen infects both root and leaf tissues and may reduce grain yield by more than 30%. The present study aimed to evaluate the resistance of fifty wheat breeding lines to B. sorokiniana under contrasting infection conditions. Field experiments were conducted over two growing seasons under natural infection, artificial inoculation, and fungicide-protected treatments. Disease severity was assessed to identify genotypes with stable resistance across years and environments. In parallel, seedling resistance was evaluated under controlled laboratory conditions to determine early-stage responses to the pathogen. Several wheat lines consistently exhibited low disease severity in the field and expressed resistance at the seedling stage. Genetic analysis revealed that many of these resistant lines carry heritable traits associated with enhanced tolerance to B. sorokiniana. The identified genotypes represent valuable genetic resources for wheat breeding programs aimed at improving disease resistance in dry agricultural regions.
Abstract
Diseases caused by Bipolaris sorokiniana, expressed as leaf spot blotch (SB) and common root rot (CRR), continue to limit spring wheat production, particularly in dry regions where yield losses may reach 35–40%. This study evaluated resistance to SB and CRR in fifty spring wheat genotypes at both seedling and adult plant stages and identified genetic sources of resistance using molecular markers linked to the Sb1 and Sb2 genes. Field trials were conducted in 2023 and 2024 in the Aktobe region under natural infection, artificial inoculation, and a fungicide-treated background. Based on leaf spot blotch severity quantified as the area under the disease progress curve (leaf AUDPC) under natural infection, nine genotypes displayed stable resistance across both years, while fungicide-treated plots revealed twenty-three resistant genotypes in 2023 and eighteen in 2024. Artificial inoculation identified five resistant lines in 2023 and one in 2024. Resistance to common root rot (CRR) was assessed independently based on subcrown internode (SCI) browning at the adult plant stage. Seedling assays confirmed consistent resistance in six genotypes, all of which carried Sb1, Sb2, or their combination. In total, Sb genes were detected in thirty-six of the fifty accessions, including genotypes from Kazakhstan, Russia, and several other countries. The presence of Sb1 or Sb2 was associated with reduced disease severity, particularly at the seedling stage. These findings identify valuable germplasm for breeding wheat with improved resistance to B. sorokiniana in Kazakhstan.
