Interspecific cross-hybrids of Nicotiana tabacum L. cv. (gla.) S 'K326' with Nicotiana alata

摘要

In order to introduce the Tomato Spotted Wilt Virus (TSWV) resistance from Nicotiana alata into Nicotiana tabacum, a cytoplasmic male sterility (CMS) line of N.tabacum (N.tabacum L. cv. (gla.) S 'K326'), was successfully crossed with N.alata. Despite a high DNA content variability, F-1 hybrids could be classified in two subgroups, a major one encompassing fertile hybrids morphologically similar to their tobacco maternal parent but TSWV sensitive, and a minor one displaying sterile hybrids showing an intermediate phenotype and TSWV resistant. In order to elucidate the unexpected fertility recovery of the fertile F-1 plants, some N.alata fertility restoration ppr genes were cloned and were shown to be differentially expressed between parental lineages as well as between both F-1 subgroups, suggesting that N.alata contains fertility restoring allele able to overcome the CMS of N.tabacum.