Govintharaj, V K and Odeny, D A and Ramalingam, J and Hepziba, J and Rengasamy, K and Habyarimana, E and Pillai, M A (2026) Gamma ray-induced phenotypic variability and mid-density SNP-based mutation characterization in forage sorghum (Sorghum bicolor L. Moench) genotype IS 33,871. Scientific Reports. pp. 1-20. ISSN 2045-2322
![[thumbnail of FM-PG Theses List.mrc]](http://oar7.icrisat.org/style/images/fileicons/text.png "FM-PG Theses List.mrc") |
Text
- Published Version
Available under License Creative Commons Attribution. Download (11kB) |
Abstract
Sorghum is an important dual-purpose cereal crop cultivated for both grain and forage, particularly in arid and semi-arid regions. However, limited genetic variability constrains the improvement of forage biomass and related agronomic traits. This study evaluated the effectiveness of gamma ray-induced mutagenesis for generating phenotypic and molecular variability in forage sorghum genotype IS 33,871. Four sorghum genotypes were initially assessed for radiosensitivity to estimate the 50% growth reduction dose (GR50), and the relatively tolerant genotype IS 33,871 was selected for bulk irradiation at 300 Gy. Evaluation of the M2 population identified a chlorophyll mutation frequency of 1.15%, confirming successful mutation induction. Substantial variation was observed for agro-morphological and biomass-related traits. Biomass fresh weight, biomass dry weight, stem girth, disease score, and panicle length exhibited high broad-sense heritability coupled with high genetic advance, indicating strong potential for effective phenotypic selection. Correlation, principal component, hierarchical clustering, and standardized deviation (Z-score) analyses identified elite mutants combining superior biomass accumulation, favourable plant architecture, and reduced disease severity. Mid-density SNP genotyping of 270 M2 individuals identified 390 homozygous mutant-specific SNPs representing 115 polymorphic loci across 16 mutants. The induced mutation spectrum was dominated by transition substitutions, although substantial variation in mutation load was observed among individual mutants. Functional annotation associated the identified SNPs with genes involved in growth, development, stress signalling, metabolism, and cellular regulation. These findings demonstrate that integrating phenotypic evaluation with SNP-based molecular characterization provides an effective strategy for identifying valuable genetic resources and accelerating forage sorghum improvement through mutation breeding.
| Item Type: | Article |
|---|---|
| Divisions: | Global Research Program - Accelerated Crop Improvement |
| CRP: | UNSPECIFIED |
| Uncontrolled Keywords: | Mutagenesis, Genetic variability, Mutation spectrum, Molecular characterization |
| Subjects: | Others > Molecular Biology Mandate crops > Sorghum Others > Genetics and Genomics |
| Depositing User: | Mr Nagaraju T |
| Date Deposited: | 29 Sep 2026 06:22 |
| Last Modified: | 29 Sep 2026 06:22 |
| URI: | http://oar7.icrisat.org/id/eprint/13698 |
| Official URL: | https://www.nature.com/articles/s41598-026-67763-9 |
| Projects: | UNSPECIFIED |
| Funders: | UNSPECIFIED |
| Acknowledgement: | Vinoth Kumar Govintharaj acknowledges the financial support received from the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India, for the conduct of this research. The authors also thank Mr. Jayakumar Jaganathan for his assistance in the execution and management of the experimental trials. |
| Links: |
Actions (login required)
 |
View Item |