Agriculture Reference
In-Depth Information
been identical to both of those. It's either one or
the other, and as it turns out, it's neither.
rosso, Aglianicone, Tronto, and maybe even
white grape varieties planted there. So unless
quite a few of the vines in that vineyard are
studied, mistakes are likely. One such problem
variety is Verdello, grapevines of which appar-
ently grow in different regions of Italy, along-
side many cultivars named Verde-Something
or Verde-like. It's quite likely that not all the
“Verdello” grapevines in a given vineyard really
are Verdello. Farmers often gave a “green-
name” to any grapevine that generically fi t the
bill (and they still do so). Thus when sampling
Verdello grapevines, the likelihood of picking
up a vine that really isn't Verdello is high, and
the skill of the ampelographer becomes of para-
mount importance. If the ampelographer mis-
takenly identifi es one of the vines as Verdello
(in a vineyard that likely contains many similar-
looking but altogether different varieties), the
DNA profi le of that grapevine will be taken to
be that of Verdello; this DNA profi le will then
be the reference DNA data for that research
group's databank. Unfortunately, if the ampelo-
grapher mistakenly identifi ed as Verdello a
similar looking but actually altogether different
grape, then future studies will inevitably con-
clude that Verdello (or what they wrongly
believe to be Verdello) is identical to yet another
grape that will be found to have the same DNA.
This is how, perhaps years later, a researcher in
another country might erroneously conclude
that a local grapevine “X” is in fact Italy's Ver-
dello, when in fact it is not, because the DNA
considered to be that of Verdello wasn't Verdel-
lo's in the fi rst place. Which leads to that
nation's grape “X” being eliminated, and called
Verdello from then on. Unfortunately, there are
numerous examples of erroneous attributions,
and these are a huge problem because they con-
vey essentially wrong information as a certi-
tude, thanks to the “end-all” that is genetic test-
ing. Researchers always conclude in their
studies that their fi ndings require that the
National Registry be changed or updated.
Those changes might not take place immedi-
ately, but in the meantime everyone refers to
the study that “determined” that two previously
DNA PROFILING: POTENTIAL PROBLEMS
AND PITFALLS
Several studies have shown that germplasm
collections harbor many homonyms and syno-
nyms (Ibanez, Andres, Molino, and Borrego
2003; Cipriani, Spadotto, Jurman, Di Gaspero,
Crespan, Meneghetti, Frare, Vignani, et al.
2010; Laucou, Lacombe, Dechesne, Siret,
Bruno, Dessup, Dessup, Ortigosa, et al. 2011).
Emanuelli, Lorenzi, Grzeskowiak, Catalano,
Stefanini, and Troggio (2013) concluded that
“further studies of grapevine genetic data are
required and that existing genetic databases
may not be the useful reference standard” they
were believed to be.
This is why some experts, such as Marisa
Fontana and Roberto Bandinelli, believe that
researchers might do better to visit areas where
varieties naturally grow, verify that the grape-
vines under examination do have ampelo-
graphic characteristics typical of the variety
they are studying, and then obtain genetic pro-
fi les of which they are certain, rather than rely-
ing simply and only on preexisting ampelo-
graphic databanks available in their home
region or country, where the standard grape-
vines may have been misidentifi ed. Clearly,
this is an expensive proposition, and therefore
leaves many cold. Still another problem with
ampelographic identifi cations is that often too
few accessions are examined. Most published
studies report mind-numbing, long lists or
tables of SSR microsatellite results performed
on many different grape varieties, but often,
carefully reading the results reveals that just a
single accession or two has been studied for
each grape variety, and that seems much too
little.
An especially big problem in Italy is that
most of the old vineyards are made up of pro-
miscuously planted grapevines: even if farmers
tell you that “this is an old vineyard of Aglia-
nico,” the chances are high there will be Piedi-
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