An extreme cytoplasmic bottleneck in the modern European cultivated potato(Solanum tuberosum) is not reflected in decreased levels of nuclear diversity
J. Provan et al., An extreme cytoplasmic bottleneck in the modern European cultivated potato(Solanum tuberosum) is not reflected in decreased levels of nuclear diversity, P ROY SOC B, 266(1419), 1999, pp. 633-639
Citations number
29
Categorie Soggetti
Experimental Biology
Journal title
PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES B-BIOLOGICAL SCIENCES
We have used the polymorphic chloroplast (cp) and nuclear simple sequence r
epeats (SSRs) to analyse levels of cytoplasmic and nuclear diversity in the
gene pool of the European cultivated potato (Solanum tuberosum sap. tubero
sum). Primers designed from the complete chloroplast sequence of tobacco (N
icotiana tabacum) were used to amplify polymorphic products in a range of p
otato cultivars. Combining the data from seven polymorphic cpSSR loci gave
26 haplotypes, one of which (haplotype A) accounted for 151 out of the 178
individuals studied and corresponded to the T-type cytoplasm previously ide
ntified in cultivated potatoes using chloroplast restriction fragment lengt
h polymorphism analysis. Phylogenetic and diversity analyses of the relatio
nships between cpSSR haplotypes confirmed much higher levels of cytoplasmic
diversity outwith the T-type group. Diversity levels at eight nuclear SSR
loci, however, were not significantly different between cytoplasmic groups,
suggesting a severe maternal bottleneck in the evolution of the modern cul
tivated potato. These results highlight the importance in quantifying level
s of cytoplasmic as well as nuclear diversity and confirm the need for a ch
ange in breeding practices to increase levels of non-T-type cytoplasm in th
e cultivated gene pool, thus helping reduce problems associated with pollen
sterility. This may be facilitated by germplasm analysis using cpSSRs, whi
ch will allow efficient selection of diverse cytoplasm donors.