Laboratory of Plant Breeding, School of Agriculture, Ibaraki University, Ami-machi, 300-03, Ibaraki-ken, Japan.
Theor Appl Genet. 1996 Aug;93(3):341-7. doi: 10.1007/BF00223174.
Interspecific hybrid plants between Nicotiana suaveolens and N. tabacum exhibit lethal symptoms at the seedling stage and cannot grow to maturity. In this investigation, an attempt was made to clarify the genomic factors responsible for this lethality. N. suaveolens was crossed to N. sylvestris (genomic constitution: SS) and N. tomentosiformis (TT), these latter two species being the progenitors of N. tabacum (SSTT). From the cross N. suaveolens x N. tomentosiformis, many seedlings were obtained through ovule culture, and these subsequently grew to maturity without exhibiting any lethality. In the reciprocal crossing between N. sauvelons and N. sylvestris, only a few hybrid seedlings were obtained through ovlue culture and all died after unfolding their cotyledons when cultured at 28 °C. This lethality could be avoided by culturing the ovules at 36 °C. These features of hybrid lethality resembled those observed in the interspecific hybrid between N. suaveolens and N. tabacum. These findings suggest that the S genome in N. tabacum is responsible for the lethality exhibited in the hybrid between N. suaveolens and N. tabacum.
甜烟与普通烟烟草种间杂种的幼苗期出现致死症状，不能成熟。本研究试图阐明导致这种致死性的基因组因素。将甜烟与普通烟烟草的祖先种——赛波烟草（SS）和黄花烟草（TT）进行杂交。从甜烟×黄花烟草的杂交中，通过胚珠培养获得了许多幼苗，这些幼苗随后成熟，没有表现出任何致死性。在甜烟与赛波烟草的反交中，通过胚珠培养仅获得少数杂种幼苗，当在 28°C 下培养时，所有幼苗在展开子叶后死亡。在 36°C 下培养可以避免这种致死性。杂种致死性的这些特征与甜烟与普通烟烟草种间杂种中观察到的特征相似。这些发现表明，普通烟烟草中的 S 基因组是导致甜烟与普通烟烟草杂种致死性的原因。
