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516 GoT mez-Campo et al.—Epicuticular Wax Columns in Brassica

Chromosome T     1. Brassica accessions utilised in this research
number (n)
8 Accession Species Seed source\origin
9 number

10 0049 Brassica nigra (L.) Koch Vejer (Spain)
17 6824 Brassica oleracea L. Granville (France)
18 — Brassica oleracea L. Cult. commercial sample
19 5971 Brassica alboglabra Bailey Gatersleben (Germany)
5719 Brassica bourgeaui (Christ) Kunze Tijarafe, La Palma, Canary
6813 Brassica montana Pourr. Ste. Margueritte (France)
6801 Brassica montana Pourr. Palmaiola (Italy)
3820 Brassica incana Ten C. Tindari, Sicily (Italy)
6558 Brassica incana Ten Capri (Italy)
6579 Brassica rupestris Rafin Cinisi (Sicily, Italy)
6582 Brassica illosa Biv. Castelmare di Golfo (Italy)
3821 Brassica illosa subsp. drepanensis (Caruel) Raim. & Mazz. Mte. Erice, Sicily (Italy)
3819 Brassica macrocarpa Guss. Egadi, Sicily (Italy)
3814 Brassica insularis Moris C. Caccia, Sardinia (Italy)
6020 Brassica cretica Lam. subsp. cretica Diakoftos (Greece)
6021 Brassica cretica subsp. aegea (Heldr. & Hal.) Snogerup et al. Euboea (Greece)
6344 Brassica cretica subsp. aegea (ibid.) Limnos (Greece)
7344 Brassica hilarionis Post Kyrenia range (Cyprus)
8431 Brassica rapa L. (canola) Prof. J. P. Tewari
Brassica carinata Braun Dr. A. de Haro
— Brassica juncea (L.) Czern Bot. Garden, Upsala
0184 Brassica napus L. (canola) Prof. J. P. Tewari
8432

(two subspecies). B. macrocarpa (Fig. 1 B), B. montana, B. Henceforth, at least five lines of partial or total hair loss
cretica and B. hilarionis. Only in B. illosa were they and parallel development of waxes can be distinguished
accompanied by abundant hairs. B. insularis columns were (Fig. 2). (a) B. rupestris is geographically confined to the
intermediate between LC and SC. Sicilian area of Palermo, between the distribution areas of
B. illosa and B. incana. B. rupestris has not completely lost
Thirdly, there were netted columns (NC) formed by LC- its hairs and presents no particular difference in the structure
like elements, apparently interlinked and often topped with of its LC waxes compared with the last two species. (b) B.
transversal columns and wax scraps. They were never insularis from Corsica, Sardinia and Tunisia has no hairs at
accompanied by hairs. Only B. oleracea, B. bourgaei (Fig. all, while it exhibits waxes of intermediate size between
1 C) and B. albograbra showed this type of wax structure. those found in the Sicilian species. (c) B. macrocarpa,
At first sight, the NC pattern appeared as an artefact but isolated in distribution in the Egadi Archipelago (NW
the same structure was seen whenever observations on Sicily), has no hairs, while its waxes are SC as in the
B. oleracea were carried out. Transversal columns are neighbouring B. illosa. (d ) B. cretica and B. hilarionis, from
often shorter than those shown in Fig. 1 C. Greece, Turkey and Cyprus, have undergone parallel
evolution (waxes of SC type and no hairs). The derivation
No waxes could be found in the leaves of the accessions of B. cretica from Sicilian material is probably indirect and
of B. nigra, B. rapa and B. juncea studied. could be related either to Tunisian B. insularis or to Adriatic
B. incana. (e) The last (fifth) line apparently derives from B.
DISCUSSION incana (on geographic and morphological grounds). It
persists with B. montana, growing on the coasts of Italy,
It has been hypothesized (Go! mez-Campo and Gustafsson, France and NE Spain. However, it has no hairs and its wax
1991) that the two densely haired Sicilian species, B. illosa columns are more like the SC type. Further to the west, the
and B. incana, are the most primitive within the group, since Atlantic kale, B. oleracea, is also glabrous and shows NC
they also show other primitive characters, such as the waxes.
presence of two (three) seeds in the pod beak (primitive only
for this group). Genetic variation is much higher in B. NC waxes are also present in B. bourgeaui and B.
illosa (where four subspecies have been recognized). Other alboglabra. Although these taxa have been listed as species
members of the group may be considered more evolved in Table 1, the opinion that both should be included within
since they have less or no hairs and their beak is further the intraspecific variability of B. oleracea is widespread
reduced to hold no more than one seed. In this respect, we (Bothmer, Gustafsson and Snogerup, 1995 ; Lanne! r, 1998).
could consider both SC and LC waxes to be associated with Our results strongly support this opinion. B. bourgeaui is a
the primitive condition represented by B. illosa and B. rare taxon from the Canary Islands, of uncertain origin and
incana. As shown here, the presence of hairs and waxes is might merely represent an ancient escaped cultivar of B.
not mutually exclusive in the Sicilian brassicas. On the other oleracea. The same can be said for B. alboglabra, a cultivated
hand, there is no particular reason why SC and LC waxes form which is supposed to have reached China in ancient
should be more primitive. times.