Vegetable Crops Unit, Agricultural Research Service, USDA, Department of Horticulture, University of Wisconsin, 53706, Madison, WI, USA.
Theor Appl Genet. 1993 Mar;86(1):128-34. doi: 10.1007/BF00223817.
Cytoplasmic-genic male-sterility systems are used to economically produce hybrid onion seed. Previous studies have indicated that the source of cytoplasmic male sterility discovered in 1925 by Jones (S-cytoplasm) may be an alien cytoplasm. Restriction enzyme analysis of the chloroplast DNA (cpDNA) revealed five polymorphisms between S and normal (N) fertile cytoplasms. S-cytoplasm was different from the Allium species closely related to the bulb onion, and cladistic estimates of phylogenies supported introduction from an unknown species. S-cytoplasm was identical for all polymorphisms in the cpDNA to 'Pran', a triploid viviparous onion. 'Pran' shares morphological characteristics with 'Italian Red 13-53', the single plant source of S-cytoplasm. Densiometric scans of autoradiograms revealed that 12 of 31 open-pollinated populations of onion possessed S-cytoplasm and that introgression may have occurred since the discovery of S-cytoplasm.
细胞质雄性不育系统被用于经济地生产杂交洋葱种子。先前的研究表明，1925 年琼斯发现的细胞质雄性不育的来源（S 细胞质）可能是一种外来细胞质。对叶绿体 DNA（cpDNA）的限制酶分析显示，S 和正常（N）可育细胞质之间存在 5 种多态性。S 细胞质与与鳞茎洋葱密切相关的葱属物种不同，系统发育的分支估计支持了未知物种的引入。S 细胞质在 cpDNA 的所有多态性上与“Pran”相同，“Pran”是一种三倍体胎生洋葱。“Pran”与“S 细胞质的唯一植株来源”意大利红 13-53“具有相同的形态特征。放射自显影密度扫描显示，31 个开放授粉洋葱群体中有 12 个具有 S 细胞质，自发现 S 细胞质以来可能已经发生了渐渗。
