Agronomy Department, Faculty of Agriculture, University of Alexandria, Egypt.
Theor Appl Genet. 1970 Jan;40(6):280-5. doi: 10.1007/BF00282038.
Seeds from two hexaploid wheat varieties, 'Giza 150' and 'Sonora 64', and the F2 seeds of their hybrid were given two mutagenic treatments, gamma irradiation and ethyl methanesulfonate (EMS), to study the type of variation and covariation in seed weight, width, and length induced by irradiation, EMS, and hybridization. Measurements of seed weight and its components were taken on 30 replicated lines derived from each treated and non-treated material.Both irradiation and EMS produced significant variability in seed weight and its components in the pure genetic background. The hybrid genetic background somewhat depressed the expression of irradiation-induced variability. The variations resulting from EMS and hybridization were to a great extent independent and cumulative.Neither EMS nor irradiation caused any significant shift in the means of seed weight, width, and length. The positive association between inheritance of width and length in irradiation-derived materials did not increase the mean seed weight compared with the control.The magnitude of the genetic correlations in irradiation varieties was double that obtained from hybrid-or EMS-derived materials. It is suggested that EMS mainly produced mutations of genes and/or minute chromosomal aberrations, whereas the genetic variation produced by gamma irradiation was accompanied by the loss and/or gain of large segments of the chromosomes.
从两个六倍体小麦品种“Giza 150”和“Sonora 64”以及它们杂种的 F2 种子中，给予两种诱变处理，γ射线辐照和甲基磺酸乙酯（EMS），以研究辐照、EMS 和杂交诱导的种子重量、宽度和长度的变异和协同变化类型。对来自每种处理和未处理材料的 30 个重复系的种子重量及其组成部分进行了测量。
辐照和 EMS 在纯遗传背景下均导致种子重量及其组成部分发生显著变异。杂种遗传背景在一定程度上抑制了辐照诱导变异的表达。EMS 和杂交产生的变异在很大程度上是独立的和累积的。EMS 和辐照都没有导致种子重量、宽度和长度均值发生任何显著变化。辐照衍生材料中宽度和长度的遗传相关性呈正相关，但与对照相比，种子重量的平均值并没有增加。在辐照品种中，遗传相关性的幅度是杂种或 EMS 衍生材料的两倍。这表明，EMS 主要产生基因和/或微小染色体畸变的突变，而γ射线辐照产生的遗传变异伴随着染色体大片段的丢失和/或获得。
