Agriculture Reference
In-Depth Information
most high-quality Sardinian estates prefer to
use massal selections of very old vines, which
are still plentiful on the island. Commonly
used synonyms for Cannonau in Italy are Ali-
cante, Gamay Perugino, and Tocai Rosso. Each
is used to make a wine highly associated with a
specifi c region and area: for example Gamay
Perugino in Umbria is used to make Trasimeno
Gamay and Tocai Rosso is used in Veneto to
make Tai (since the word
tocai
can no longer be
used to designate wines made outside Hun-
gary). However, Cannonau and Tocai Rosso are
not identical; there is one allele that helps dis-
criminate between Tocai Rosso and Cannonau
(and Garnacha). Therefore, it is more correct to
consider Tocai Rosso a biotype of Cannonau,
since it has adapted over the decades to a com-
pletely different environment (Veneto instead
of Sardinia). Tocai Rosso seems a relative new-
comer to Veneto, but perhaps earlier experts
simply failed to recognize it. In fairness, the
two grapevines look slightly different: Tocai
Rosso has slightly bigger, more compact
bunches and berries with thicker skins. Cer-
tainly producers in Sardinia feel that there is a
night-and-day difference in quality between the
two—but then, one
would
expect them to
believe that. It may not be a matter of one bio-
type being much higher quality than the other,
but rather of the variety adapting over the cen-
turies to a specifi c habitat and becoming more
successful in producing interesting wines
there.
Recent study results suggest there is a
genetic basis to growers' long-held belief that
the various Cannonau biotypes aren't at all
alike, despite their presumed genetic identity.
In the 2011 study by Meneghetti's group,
molecular tests were able to separate samples
into distinct groups based on their respective
origin (Sardinia, Sicily, Umbria, Vicenza prov-
ince, Spain, and France). In the study, Can-
nonau accessions fell in the fi rst group while
all the remaining accessions clustered into
three different subgroups of a second group. It
follows that if genetic tests can separate
between grapevines on the basis of their place
of origin, and that these cultivars exhibit a
spectrum of morphologic and viticultural
diversity, then it is likely that such differences
are refl ected in the characteristics of the wines
made in each specifi c region. Therefore, the
impression that growers have about there being
noteworthy differences between Cannonau
and Tocai Rosso, for example, and the wines
made with them, may not be a fi gment of their
imagination.
In fact, Cannonau is a textbook example of
the damage that can be wreaked by careless
nursery practices. In the 1980s, when Italy's
wine boom was beginning to take shape, grow-
ers turned to nurseries in order to increase
their plantings of Cannonau, which was fast
becoming a hot commodity. Unfortunately, in
the words of well-respected producer Alessan-
dro Dettori “probably because of a sense of
urgency that did nothing for attention to detail,
varieties other than Cannonau (or at best, low-
quality biotypes) were shipped to Sardinia. The
University of Sassari has estimated that 80 per-
cent of the Cannonau vines planted on the
island are of the low-quality Tocai Rosso bio-
type. I don't know if this is true. I know my
vines are almost one hundred years old and
don't come from nursery selections, and that's
what really matters to me.” At the Alberto Loi
estate, where the grandfather of the present
owners fi rst planted Cannonau vines at the
turn of the twentieth century, they believe that
“studies have shown genetic diversity between
populations of Cannonau grown in different
parts of the island, so it is important to avoid
bringing in plant material from outside the
island. At Loi, we'd even go further, and veto
the mixing of Cannonau biotypes from within
different areas of the island itself. Each should
remain planted in its own
terroir,
for the varie-
ties behave differently and so do the wines.”
Slightly different-looking Cannonau grape-
vines are found in vineyards located near
Alghero, Barisardo, Quartu Santa Elena, Sen-
nori, and Cagliari: all show the same genetic
profi le at fourteen SSR loci. Studies of the exact
characterization of the organoleptic features of
