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Biochemical analysis of Brassica seeds 627

The genus Brassica sect. Brassica of the cytodeme 1999; Kurlich et al. 1999), but it is not known to
of B. oleracea L. (Harbert 1972) is distributed in the what degree the antioxidant content varies among
Mediterranean area (Raimondo et al. 1991) and is wild species.
represented by: B. oleracea L.; B. villosa Biv. subsp. The objective of our study was to investigate the
villosa; B. villosa subsp. bivonana (Mazzola & content of phytochemicals, such as Toc, FA and
Raimondo) Raimondo & Mazzola; B. villosa subsp. phytosterols in the seeds of nine wild entities of
drepanensis (Caruel) Raimondo & Mazzola; B. villosa Sicilian Brassicaceae and to determine whether these
subsp. tinei (Lojac.) Raimondo & Mazzola; B. villosa phytochemicals could be used to discriminate the
subsp. brevisiliqua (Raimondo & Mazzola) seeds. The results could be useful for developing
Raimondo & Geraci (= B. rupestris subsp. brevisiliqua genotypes with potential health benefits.
Raimondo & Mazzola); B. rupestris Raf. subsp. rupes-
tris; B. rupestris subsp. hispida Raimondo & Mazzola;
Materials and methods
B. macrocarpa Guss.; B. incana Ten.; B. insularis
Moris (Raimondo & Mazzola 1997; Giardina et al. Seed materials
2007). With the exception of B. oleracea, B. incana
Analyses were performed on seeds collected from
and B. insularis, the others are endemic to Sicily
nine Sicilian populations of different species and
(Conti et al. 2005), including some that are consid-
subspecies of Brassica and coded from B1 to B9 as
ered to be endangered (Raimondo et al. 1994).
reported in Table I. Seeds were collected from 50
Some of these taxa are interesting as wild progeni-
plants for each population, sealed in glass bottles and
tors of the numerous forms and cultivated varieties
Downloaded By: [Scialabba, A.] At: 20:01 10 October 2010
then stored at 6% RH and −20°C at the Germplasm
of cabbages (Heywood & Zohary 1995).
Bank of the Palermo Botanical Garden (Italy).
Morphological (Raimondo & Mazzola 1997),
High vigour seeds with a germination percentage
proteome (Lazaro & Aguinagalde 1998) and molec-
ranging from 80% (B. villosa subsp. bivonana) to
ular analyses (Lazaro & Aguinagalde 1996; Geraci
94% (B. macrocarpa) were used in the present study.
et al. 2001) have been performed to obtain insight
One hundred seeds per population were processed
into the relationships between populations of wild
to determine dry weight (DW) by placing seeds in an
Brassica. As the seeds of some taxa of Brassica have
oven at 103°C for 18 h.
almost identical morphological and anatomical
structures, it is not possible to use these as diagnostic
characters for the infraspecific attribution (Scialabba
Gas chromatography-mass spectroscopy
& Raimondo 1995). Phytochemical studies address-
(GC-MS) analysis
ing vitamin E, fatty acid (FA) and phytosterol
contents, which could be used as species-specific One hundred milligrams of seed were homogenised
diagnostic characters, have not yet been performed. in n-hexane at 4°C for 60 s and centrifuged at
Within and between cultivated genotypes of B. 10,000 g, 20 min. An aliquot of the extract (150 µL)
oleracea, a substantial variation in vitamin E and high was dried in a nitrogen stream. Trimethylsilylation
antioxidant capacity was reported (Azuma et al. was then performed, by adding 50 µL N,O-
Table I. Code, population, collection site and accession number of Brassica species and subspecies used for tocopherol, fatty acid and
phytosterol analyses.
Code Population Collection site Accession number
B1 B. rupestris Raf. subsp. rupestris San Ciro 354
(Palermo)
B2 B. rupestris subsp. hispida Raimondo & Mazzola Monte Pizzuta 700
(Palermo)
B3 B. villosa Biv. subsp. villosa Sagana 340
(Palermo)
B4 B. villosa subsp. bivonana (Mazzola & Raimondo) Zingaro Natural Reserve 701
Raimondo & Mazzola (Trapani)
B5 B. villosa subsp. brevisiliqua Isolidda 699
(Raimondo & Mazzola) Raimondo & Mazzola (Trapani)
B6 B. villosa subsp. drepanensis (Caruel) Monte San Giuliano 704
Raimondo & Mazzola (Trapani)
B7 B. villosa subsp. tinei (Lojac.) Raimondo & Mazzola Marianopoli 343
(Caltanissetta)
B8 B. incana Ten. Gonato 366
(Madonie, Palermo)
B9 B. macrocarpa Guss. Favignana 368
(Egadi Islands)