Biology Group, Directorate General XII, J.R.C. of European Communities, I-21020, Ispra, Italy.
Theor Appl Genet. 1985 Jun;70(3):259-64. doi: 10.1007/BF00304909.
Leaf protoplasts isolated from haploid and dihaploid Nicotiana plumbaginifolia plantlets were treated with different doses of gamma-rays and their survival was determined by scoring for plating efficiency at each irradiation dose. A fixed number of surviving protoplast-derived colonies was then plated in the presence of inhibitory concentrations of L-valine and incubated until growing resistant calli could be scored and mutation rates calculated. Though haploid protoplasts were found to be a little more sensitive than dihaploids to the lethal effect of radiation, the two dose-response curves of gamma-rays that induced mutagenesis were very similar. The irradiation dose capable of causing a ten-fold increase of spontaneous mutation frequencies was about 500 rads with both haploid and dihaploid protoplasts.
从单倍体和二倍体菸草小植株中分离的叶原生质体用不同剂量的γ射线处理，并用平板效率评分来确定每种辐射剂量下的存活率。然后，在存在 L-缬氨酸抑制浓度的情况下，将一定数量的存活原生质体衍生菌落平板接种，并培养至可以评分生长抗性愈伤组织和计算突变率。尽管发现单倍体原生质体比二倍体原生质体对辐射的致死效应稍微敏感一些，但诱导突变的两条γ射线剂量反应曲线非常相似。引起自发突变频率增加十倍的照射剂量约为 500 拉德，单倍体和二倍体原生质体都是如此。
