Abstract:
The imposition of managed water deficit and early l
eaf removal are strategies used to
improve the grapes quality in terms of anthocyanin
content. The aim of our work was to
evaluate the change in total anthocyanin levels dur
ing the ripening of the Sicilian grapes
(Nero d'Avola and Frappato) and of the internationa
l variety of Cabernet Sauvignon,
subjected to two different levels of water deficit,
0% (NI) and 30% (I) of estimated crop
evapotranspiration, and subjected to Early Leaf Rem
oval (ELR) or Not (NLR). The
expression of genes involved in anthocyanin biosynt
hesis, such as Phenylalanine
Ammonia Lyase (PAL) and UDP-glucose-Flavonoid-Gluco
syl Transferase (UFGT), was
also monitored. Our results indicate that the amoun
t of anthocyanin during the ripening
process can be regulated by the application of the
aforementioned agronomic practises.
The anthocyanin content of Cabernet Sauvignon may b
e risen either by the simultaneous
application of Early Leaf Removal and in water rest
itution regime (ELR-I) or by the
association of water deficit and absence of defolia
tion (NLR-NI). The analysis of the total
content of anthocyanin in Frappato variety has glob
ally revealed that the maximum value
in the levels of pigments is reached later than in
the other autochthonous Nero d'Avola
variety. This finding is of considerable interest s
ince both the harvest time and product
processing might be differentiated among varieties.
Conversely, the variety Nero d'Avola
was not affected by the experimental conditions and
showed the highest level of pigments
at fully ripe time.
Keywords:
Anthocyanin, Early leaf removal, PAL, UFGT,
Vitis vinifera
, Water deficit.
