Hayes and Garber - Cucurbit Breeding

POTATO
CHAPTER XVI
IMPROVEMENT
Potatoes have been generally introduced into cultivation
since the discovery of America, and are now a crop of major importance
in many countries. The large number of varieties is an
illustration of the rapid development in domestic plants of varieties
which are suited to special soil and climatic conditions. As
potatoes are reproduced commercially by tubers, they furnish an
excellent illustration of the way in which vegetative reproduction
modifies breeding methods.
Origin and Species. There are from five to 100 species of
tuber-bearing potatoes according to the number of forms which
are recognized as separate species (East, 19086: Wight, 1916).
Whether the cultivated potato arose from a single wild species or
from several is a debatable question. The preponderance of
opinion is that there is only a single wild species, Solarium tubero^
sum L., which deserves to be considered as the stem form from
which all cultivated varieties arose. Wight (1916), after carefully
examining herbarium material, previous records, and wild
species, makes the following statements:
" Every reported occurrence of wild S. tuberosum that I have been
able to trace to a specimen, either living or preserved in the herbarium,
has proved to be a different species. I have not found in any of the
principal European collections a single specimen of Solarium tuberosum
collected in an undoubted wild state."
Berthault (1911) cites Heckel, Planchon. and Labergerie as
examples of recent workers who believe that other wild species
gave cultivated S. tuberosum forms by mutation; Planchon beliving
that the original form was S. commersonii', Heckel that
S. maglia through mutation produced cultivated potatoes; while
Labergerie believed both of these species gave cultivated forms
through mutation. Berthault attempted to answer the question
by growing seeds and tubers of both these species and also by
growing seed of several cultivated varieties. Progeny of seed or
tubers of S. maglia and S. commersonii gave no forms which
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