Ionizing irradiation induces positive or negative changes in plant growth (M1) depending on the amount of irradiation applied to seeds or plant parts. The effect of 50–350 Gy gamma irradiation of kernels on nucleolar activity, as an indicator of metabolic activity, in root tip cells of tetraploid wheat Triticum turgidum ssp. durum L. cv. Orania (AABB) was investigated. The number of nucleoli present in nuclei and micronuclei as well as the mitotic index in the different irradiation dosages was used as an indicator of the cells entering mitosis, the chromosomes with nucleolar organizer regions that are active as well as chromosome doubling in the event of unsuccessful mitotic division. Nucleolar activity was investigated from 17.5 to 47.5 h after the onset of imbibition to study the first mitotic division and its consequences on the cells that were in G₂ and G₁ phases at the time of gamma irradiation. Untreated material produced a maximum of four nucleoli formed by the nucleolar organizing regions (NORs) on chromosomes 1B and 6B. In irradiated material, additional nucleoli were noted that are due to the activation of the NORs on chromosome 1A in micronuclei. The onset of mitosis was highly significantly retarded in comparison to the control due to checkpoints in the G₂ phase for the repairing of damaged DNA. This study is the first to report on the appearance of nucleoli in micronuclei as well as activation of NORs in the micronuclei that are inactive in the nucleus and the effect of chromosome doubling on nucleolar activity in the event of unsuccessful mitotic division.

电离辐照会引起植物生长 (M1) 的正或负变化，具体取决于施加于种子或植物部分的辐照量。50-350 Gy 伽马辐照对四倍体小麦Triticum turgidum ssp根尖细胞核仁活性的影响，作为代谢活性的指标。硬粒小麦L.简历。Orania (AABB) 进行了调查。细胞核和微核中存在的核仁数量以及不同辐照剂量下的有丝分裂指数被用作细胞进入有丝分裂的指标，具有活跃的核仁组织区的染色体以及在不成功的情况下染色体加倍有丝分裂。在吸入开始后 17.5 至 47.5 小时研究核仁活性，以研究第一次有丝分裂及其对 G ₂和 G _{1细胞的影响}γ辐照时的相位。未经处理的材料产生最多四个核仁，这些核仁由染色体 1B 和 6B 上的核仁组织区 (NOR) 形成。在辐照材料中，注意到额外的核仁是由于微核中染色体 1A 上 NOR 的激活。与对照相比，由于在 G ₂期存在用于修复受损 DNA 的检查点，有丝分裂的开始显着延迟。这项研究首次报道了微核中核仁的出现以及在核中无活性的微核中的 NOR 的激活，以及在有丝分裂不成功的情况下染色体加倍对核仁活性的影响。