Department of Botany, University of Texas, Austin, Texas 78712.
Genetics. 1975 Mar;79(3):493-512. doi: 10.1093/genetics/79.3.493.
Genic heterozygosity and variation were studied in the permanent translocation heterozygotes Oenothera biennis I, Oe. biennis II, Oe. biennis III, Oe. strigosa, Oe. parviflora I, Oe. parviflora II, and in the related bivalent formers Oe. argillicola and Oe. hookeri. From variation at 20 enzyme loci, we find that translocation heterozygosity for the entire chromosome complex is accompanied by only moderate levels of genic heterozygosity: 2.8% in Oe. strigosa, 9.5% in Oe. biennis and 14.9% in Oe. parviflora. Inbred garden strains of Oe. argillicola exhibited 8% heterozygosity; neither garden nor wild strains of Oe. hookeri displayed heterozygosity and only a single allozyme genotype was found. The mean number of alleles per locus is only 1.30 in Oe. strigosa, 1.40 in Oe. biennis, and 1.55 in Oe. parviflora, compared to 1.40 in Oe. argillicola. Clearly, the ability to accumulate and/or retain heterozygosity and variability has not been accompanied by extraordinary levels of either. Clinal variation is evident at some loci in each ring-former. A given translocation complex may vary geographically in its allozymic constitution. From gene frequencies, Oe. biennis I, II, and III, Oe. strigosa and Oe. hookeri are judged to be very closely related, whereas Oe. argillicola seems quite remote; Oe. parviflora is intermediate to the two phylads. Gene frequencies also suggest that Oe. argillicola diverged from the Euoenothera progenitor about 1,000,000 years ago, whereas most of the remaining evolution in the complex has occurred within the last 150,000 years.
研究了永久易位杂合体欧报春 I、欧报春 II、欧报春 III、欧报春、欧报春 I、欧报春 II 和相关的二价形成者欧报春 argillicola 和 Oe. hookeri 的基因杂合性和变异。从 20 个酶基因座的变异中，我们发现整个染色体复合体的易位杂合性仅伴有适度的基因杂合性：欧报春 strigosa 为 2.8%，欧报春 biennis 为 9.5%，欧报春 parviflora 为 14.9%。欧报春 argillicola 的近交花园品系表现出 8%的杂合性；既没有发现野生品系的欧报春 hookeri 具有杂合性，也只发现了一种同工酶基因型。每个基因座的等位基因平均数仅为 1.30 在欧报春 strigosa，1.40 在欧报春 biennis，和 1.55 在欧报春 parviflora，而在欧报春 argillicola 中则为 1.40。显然，积累和/或保留杂合性和可变性的能力并没有伴随着非凡的水平。在每个环形成者中，有些基因座都存在梯度变异。给定的易位复合体在其等位基因组成上可能在地理上有所不同。从基因频率来看，欧报春 I、II 和 III、欧报春 strigosa 和欧报春 hookeri 被认为非常密切相关，而欧报春 argillicola 似乎相当遥远；欧报春 parviflora 介于两者之间。基因频率还表明，欧报春 argillicola 与 Euoenothera 祖先分化约 100 万年前，而该复合体的大部分进化是在过去 15 万年发生的。
