BACKGROUND Potato brown rot, caused by Ralstonia solanacearum, is an important quarantine disease that can seriously affect tuber quality and limit the movement and marketability of potatoes. Gamma irradiation may help control the pathogen after harvest, but the dose used can also affect the nutritional value and quality of potato tubers. PURPOSE We aimed to study the genetic diversity of the potato brown rot pathogen, Ralstonia solanacearum, using molecular markers. We also evaluated how irradiation affects the physicochemical properties of treated and untreated potato tubers. MATERIALS AND METHODS Commercial potato varieties were collected from major potato-growing areas of Bangladesh for pathogen isolation and irradiation studies. Forty-two bacterial isolates were characterized on TTC medium and examined using PS-1/PS-2 PCR, 16S rRNA sequencing, phylotype-specific PCR, and mutS amplification. After irradiation, the tubers were assessed for weight loss, ascorbic acid, anthocyanin, carotenoid, total soluble solids (TSS), and mineral content. RESULTS Virulent isolates produced the expected 553-bp PS-1/PS-2 amplicon. Sequence analysis placed a representative isolate close to Asian Ralstonia reference strains, while phylotype-specific PCR generated a 213-bp product corresponding to phylotype IV. The pathogen-specific 553-bp amplicon remained detectable up to 5.5 kGy but was not detected at 6 kGy under the conditions used in this study. A reduction in mutS band intensity was also observed following irradiation. The effects of irradiation on tuber quality varied with cultivar and dose. Ascorbic acid and carotenoid contents generally decreased with increasing irradiation dose, whereas anthocyanin and TSS remained comparatively stable. Mineral concentrations were generally higher in irradiated tubers than in untreated samples. CONCLUSION Gamma irradiation reduced the detectability of the pathogen-specific PCR target, although this does not confirm complete pathogen inactivation. Irradiation conditions require optimization to balance pathogen suppression and nutritional quality. Further viability testing and genomic characterization are recommended.
PURPOSE Wheat blast, caused by the fungus Magnaporthe oryzae Triticum (MoT), is an escalating threat to global food security due to its devastating impact on yield. Classical breeding for durable resistance is limited by scarce genetic resources. This study aimed to address this critical need by utilizing mutation breeding with gamma-ray irradiation to develop blast-resistant wheat lines. MATERIALS AND METHODS Seeds from five popular high-yielding Bangladeshi wheat varieties viz. BARI Gom 27, BARI Gom 28, BARI Gom 29, BARI Gom 30, and BARI Gom 33, were treated with doses of gamma rays (200 Gy, 250 Gy, and 300 Gy). The mutant population was screened in subsequent generations for disease resistance and agronomic performances. Detached leaf assay (DLA) was used as a preliminary screening method on M2 progenies. The resistance of selected lines was then validated through artificial inoculation of MoT under field conditions in the M3 generation. RESULTS Out of 1710 total M1 plants that survived gamma-ray treatment, preliminary bioassay results (DLA) revealed that nine gamma-irradiated M2 progenies demonstrated strong resistance against MoT. After field screening with artificial inoculation in the M3 generation, we identified five mutants out of 225 plants. These artificially inoculated M3 plants showed differential reactions to MoT infection. Specifically, two entries were observed to be completely free from blast infection (0% disease incidence and severity), while another three entries had low disease severity (0.17-1.0%) and disease incidence (3-4%) with high grain yield. CONCLUSIONS The two promising M3 mutant lines developed through gamma irradiation of seeds represent strong candidates for the development of a blast-resistant wheat variety. Their high level of resistance and improved grain yield under field conditions make them invaluable genetic resources. Further field screening and bioassays are warranted to ensure stable varietal development.
Background Understanding the radiosensitivity status of patients may provide crucial insight for planning personalized treatment when high doses of ionizing radiation are part of treatment regimen. This is particularly relevant in case of pediatric patients who are to undergo myeloablative conditioning prior to hematopoietic stem cell transplantation (HSCT). Assessment of cytogenetic aberrations following irradiation using conventional blood culture is standard approach for evaluating radiosensitivity. However, in certain disorders, cells often exhibit poor proliferation, leading to culture failure. In such instances, aberration assessment with G(0)-phase premature chromosome condensation (G(0)-PCC) without culture may provide a suitable alternative. Purpose In the current study, we have assessed baseline and radiation induced chromosome aberrations among three pediatric candidates for HSCT who were diagnosed with rare inborn errors of immunity disorders; Fanconi anemia (FA), leukocyte adhesion deficiency-I (LAD I) and Wiskott-Aldrich syndrome (WAS) using the G(0)-PCC with fluorescence in situ hybridization (G(0)-PCC-FISH) assay. Methodology Blood samples were exposed to 2 Gy gamma radiation. Baseline and radiation-induced chromosomal aberrations were quantified with G(0)-PCC-FISH and compared with baselines from healthy controls. Results All three cases demonstrated elevated radiation-induced aberration frequencies, indicating increased radiosensitivity and impaired DNA repair capacity. Conclusions These findings highlight the potential utility of G(0)-PCC-FISH as a rapid tool for radiosensitivity assessment. Especially useful when metaphases are difficult obtain due to failing cultures.
