Department of Vegetable Crops, University of California, 95616, Davis, CA, USA.
Theor Appl Genet. 1983 Nov;67(1):17-24. doi: 10.1007/BF00303916.
Reciprocal sexual crosses were performed to produce plants heterozygous at four nuclear loci, two of which coded for phosphoglucomutase (PGM) and shikimic acid dehydrogenase (SDH) isozymes and could be visualized in petiole callus tissue. Clones of one reciprocal always exhibited the heterozygous phenotype at both isozyme loci, but 25.8% of clones of the other exhibited loss of the fast migrating electromorph at the PGM locus while remaining 100% heterozygous at the SDH locus. No reversion to heterozygosity was observed and the variant phenotype was transmitted to regenerated plantlets. All regenerates were karyologically and developmentally abnormal, and studies of the inheritance of this variability were therefore not possible. Epigenetic change, point mutation, and somatic recombination were ruled out as possible causes due to gross incongruencies with the phenomenon. No consistent differences between normal and variant clones were detected with respect to chromosome number, structure, and anomalous disjunction.
进行了正反交杂交，以产生在四个核基因座杂合的植物，其中两个基因座编码磷酸葡萄糖变位酶（PGM）和莽草酸脱氢酶（SDH）同工酶，可以在叶柄愈伤组织中观察到。一种杂交的克隆总是在两个同工酶基因座表现出杂合表型，但另一种杂交的 25.8%的克隆在 PGM 基因座失去了快速迁移的电形态，而在 SDH 基因座仍然保持 100%杂合。没有观察到回复到杂合性，并且变体表型被传递到再生的小植株。所有再生的植物都表现出染色体和发育异常，因此不可能对这种变异性的遗传进行研究。由于与现象严重不一致，因此排除了表观遗传变化、点突变和体细胞重组作为可能的原因。在染色体数量、结构和异常分离方面，正常和变体克隆之间没有一致的差异。
