Production Practices and Quality Assessment of Food Crops. Vol. 1

Chestnut, an Ancient Crop with Future 121
In chestnut, grafting it is an old technique used for propagating cultivars.
According to the high variability found in the old orchards (Pereira-Lorenzo et
al., 1996a and b), growers could have propagated multiple local selections from wild
populations established previously in the same area (Figure 7). This process is
dynamic and it still continues in some countries such as Slovenia; with the aim to
improve the quality of the nut production by selecting the most interesting genotypes
and propagating them by grafting (Solar et al., 2001).
Most of the cultivars are polyclonal, but some of them have been broadly spread
(Pereira-Lorenzo et al., 1996 a and b) such as ‘Parede’ in Northern Spain (Pereira-
Lorenzo et al., 2001a). First study reporting intra-cultivar variability was in the
important cultivar Marrone Fiorentino (Borghetti et al., 1983), finding important
differences between localities as it was suggested by Morettini and Saccardi (1951)
previously.
Morettini and Saccardi (1951) explained this by the fact that the number of
cultivars in orchards is high due to its frequency that growers cultivated such
seedlings. Some of these seedlings, which produce good nuts, were then used as
mother trees for grafting. The best of them are propagated into new localities. As
a consequence, the number of local cultivars is often detectably high.
The main characters to be fixed are those related with nut quality. One of the
most important could be mono-embryonic nut versus poly-embryonic. Mono-embryonic
nuts were named ‘marroni’ type in Italy in Medieval Ages. It could be related
with the transformation of this kind of nuts without inner peel in ‘marron glacé’.
Cultivars producing poly-embryonic nuts are named chestnut type. In Europe, most
of the cultivars are ‘marron’ type (Breisch, 1995; Paglietta and Bounous, 1979;
Pereira-Lorenzo and Fernandez-Lopez, 1997a). Nut size, ease of peeling, sweetness,
and colour were other characteristics appreciated by growers and consumers.
In China, selection from seedling orchards by grafting the best accessions is a
new program developed recently (Liu and Zhou, 1999), and forty excellent cultivars
have been introduced in the germplasm bank of the Institute of Botany of
Nanjing.
It is reckon that the botanist Pier Antonio Micheli (Enumeratio rariorum plantarum
(Manoscr.), cited by Breviglieri, 1955) was the first to distinguishing the
chestnut cultivars based in a study of the bur, fruit, leaf and flower.
In France, Tricaud, Lamy of Lachapelle and, principally Lavialle (1911, cited
by Breviglieri, 1955) described 60 French cultivars, using the samples showed in
the international exhibition of chestnut celebrated in Limoges in 1910.
Piccioli (1922, cited by Breviglieri, 1955) described nearly 300 Italian cultivars,
classified by regions and harvesting time, and Remondino (1926, cited by
Breviglieri, 1955) referenced near 1000 denominations, many of them synonymous.
Breviglieri (1955) defined the ‘Squeda Castanografica sul Castagno’, and established
the base work for further studies. He was the first in classifying chestnut
cultivars in two main groups: ‘marron’ and chestnut types. Cultivars ‘marron’
types produce less than 70 nuts per kg, one or two nuts by bur, mono-embryonic
nuts, pericarp of bright colour with stripes, ease in peeling and sweet. In 1977,
Bagnaresi et al. described cultivars from Toscana and Emilia Romagna in Italy,