Department of Botany, University of Rhode Island, Kingston, Rhode Island, USA.
Theor Appl Genet. 1973 Jan;43(3-4):190-5. doi: 10.1007/BF00306570.
A study was made of the effects of pre-meiotic x-irradiation on the bronze locus in chromosome 9 of maize. Plants of Sh Bz Wx/Sh Bz Wx constitution were treated with ca. 1000r and pollen from these individuals was applied to silks of sh bz wx tester plants. In the F1 progeny, three Sh Wx kernels having a bz aleurone or showing Bz-bz variegation (the bz-x3, bz-x4 and bz-x5 mutants) were selected as possible mutations at the bz locus. One kernel of sh bz wx phenotype as well as one exhibiting sh, bz and Wx (sh-bz-x3) were also selected for more intensive study. Progeny tests of the sh bz wx individual along with cytological observations indicated that a ring chromosome was the probable cause of the mutant phenotype although an alternative hypothesis is not ruled out. The behavior of sh-bz-x3 can be interpreted as the result of either a minute deficiency involving the Sh and Bz loci or a simultaneous suppression of the two dominant alleles. Progeny of the bz-x mutants exhibited genetic instability of bronze. It is hypothesized that this behavior is due to the activation or alteration by x-rays of gene control mechanisms which affect the bronze gene.
这项研究旨在探讨减数分裂前的 X 射线辐射对玉米 9 号染色体青铜座位的影响。Sh Bz Wx/Sh Bz Wx 品系的植株接受了约 1000r 的辐射，然后将这些个体的花粉应用于 sh bz wx 测试植株的花丝上。在 F1 后代中，选择了三个具有 bz 糊粉层或表现出 Bz-bz 嵌合体（bz-x3、bz-x4 和 bz-x5 突变体）的 Sh Wx 籽粒，作为 bz 座位可能的突变体。还选择了一个具有 sh bz wx 表型的籽粒和一个表现出 sh、bz 和 Wx（sh-bz-x3）的籽粒进行更深入的研究。对 sh bz wx 个体的后代测试以及细胞学观察表明，尽管不能排除替代假说，但环状染色体可能是突变表型的原因。sh-bz-x3 的行为可以解释为涉及 Sh 和 Bz 基因座的微小缺失或两个显性等位基因的同时抑制。bz-x 突变体的后代表现出青铜的遗传不稳定性。假设这种行为是由于 X 射线激活或改变了影响青铜基因的基因调控机制。
