Agriculture Reference
In-Depth Information
2
Taxonomy
Ronald G. van den Berg* and N. Groendijk-Wilders
Biosystematics Group, Wageningen University, the Netherlands
The taxonomy of “the potato”,
Solanum
L. section
Petota
Dumort, encompassing both the wild rela-
tives of the cultivated potato and the cultigen itself,
has a long, convoluted history. In the present
chapter, we will summarize this history briefly,
describe the current state of affairs that is influ-
enced heavily by the use of molecular data, and
look at future developments, especially the im-
pact of genomic data. We will first deal with
what is known about the wild potatoes, and then
look at the various ways the potato crop has
been classified. It should become apparent to
what extent these two taxonomic situations have
become clear through recent research, and to
what extent a standardization has been reached
that is generally accepted. Finally, as more and
more genomic data become available, we need to
discuss possible ways the taxonomy of the potato
can benefit from these.
the crop, the classification and phylogeny of
these species must be clear. Different taxonom-
ists have, however, arrived at different results,
and such controversies can hamper the utiliza-
tion of the crop's wild relatives and pose prob-
lems for gene bank management. Here, we look
briefly at the history of the taxonomic classifica-
tion of the wild relatives and discuss remaining
problems and the current situation.
A brief outline of the history
of potato taxonomy
The genus
Solanum
L. is a large genus, with ap-
proximately 900 species (Hawkes, 1990). The
tuber-bearing species attracted attention early
on and were recognized as a separate group: sec-
tion
Tuberarium
, with representatives from the
southern part of the USA to Chile. The number
of species assigned to this section grew rapidly
since Walpers (1844-1845) described ten spe-
cies, especially with the work of Bitter (1912),
who added more than
50
species. Russian tax-
onomists, Bukasov (1933), for example, added
even more, recognizing minor variants as spe-
cies. In an early publication, Hawkes (1944), ap-
plying the same ''splitter'' approach, recognized
150
wild and
20
cultivated species. This approach
2.1
Classification of the Wild
Relatives of the Potato
The potato is a crop with a large number of wild
relatives, a group of more than
100
tuber-bearing
Solanum
species, mostly in the Andes mountain
range. In order to use these related species as
sources of traits useful for the improvement of
