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630 A. Scialabba et al.

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Table IV. Phytosterol content (mean mg kg DW ± standard deviation) and percentage composition of total phytosterols (%) of Brassica
seeds. T-Phy, total phytosterol content. Means within a column followed by the same letter do not differ significantly at P ≤ 0.05 as
determined by Tukey’s test.
Sitosterol Campesterol Brassicasterol T-Phy
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Code mg kg DW % mg kg DW % mg kg DW % mg kg DW
B1 279.2 ± 12.2 65.4 65.4 ± 2.4 15.3 82.2 ± 5.1 19.3 426.9 ± 18.3 b
B2 194.4 ± 6.5 66.8 41.7 ± 3.4 14.3 55.1 ± 5.2 18.9 291.1 ± 4.7 ab
B3 313.9 ± 12.3 63.3 91.2 ± 8.9 18.4 90.6 ± 4.1 18.3 495.7 ± 24.0 c
B4 388.6 ± 14.4 68.7 68.7 ± 5.5 12.2 108.1 ± 11.0 19.1 565.4 ± 19.1 c
B5 225.3 ± 19.5 62.1 69.2 ± 7.4 19.1 68.2 ± 6.3 18.8 362.7 ± 25.6 b
B6 317.7 ± 19.7 69.6 66.2 ± 8.1 14.5 72.9 ± 6.0 16.0 456.8 ± 19.3 c
B7 359.2 ± 28.1 69.3 61.8 ± 6.9 11.9 97.0 ± 6.6 18.7 518.0 ± 15.6 c
B8 160.5 ± 15.5 61.7 53.8 ± 8.2 20.7 45.8 ± 5.4 17.6 260.1 ± 17.9 a
B9 196.5 ± 14.4 67.9 46.8 ± 4.7 16.2 46.2 ± 6.2 16.0 289.4 ± 12.9 a
B1. B. rupestris Raf. subsp. rupestris, B2. B. rupestris subsp. hispida Raimondo & Mazzola, B3. B. villosa Biv. subsp. villosa, B4. B. villosa
subsp. bivonana (Mazzola & Raimondo) Raimondo & Mazzola, B5. B. villosa subsp. brevisiliqua (Raimondo & Mazzola) Raimondo &
Mazzola, B6. B. villosa subsp. drepanensis (Caruel) Raimondo & Mazzola, B7. B. villosa subsp. tinei (Lojac.) Raimondo & Mazzola, B8.
B. incana Ten., B9. B. macrocarpa Guss.

Furthermore, all the differences detected among dependent (Kurlich et al. 1999). In a chemotaxo-
Downloaded By: [Scialabba, A.] At: 20:01 10 October 2010
the nine accessions of Brassica for individual and nomic study on 91 species of Brassicaceae (=
total phytosterols (T-Phy) were significant for sito- Cruciferae), where the significance of Toc and the
sterol (F (8,18) = 94.7; P ≤ 0.00001), campesterol relationship with oil content and FA profile was
(F (8,18) = 14.95; P ≤ 0.00001), brassicasterol (F (8,18) studied, it was observed that Toc content in these
= 35.8; P ≤ 0.00001) and for T-Phy (F (8,18) = 109.5; species was useful to support assignment to sub-
P ≤ 0.00001). T-Phy were significantly higher in the tribes (Goffman et al. 1999). In the genotypes of
B. villosa group, except for B5, than in other entities Sicilian Brassicaceae, α- and γ-Toc were the major
(Table IV). In B8–B9 (B. incana and B. macro- isomers detected and T-Toc content and the rela-
carpa), T-Phy content was similar to that of B2 tive percentage of single isoforms were useful for
(B. rupestris subsp. hispida). In all species and the characterisation of Brassica seeds. On the basis
subspecies, sytosterol was the most abundant (61.7– of these results, B. rupestris subsp. rupestris, B. r.
69.6% relative to T-Phy), followed by brassicasterol subsp. hispida and B. villosa subsp. brevisiliqua
and campesterol at 16.0–19.8% and 11.9–20.7%, previously described as subsp. of B. rupestris can be
respectively. Correlation analyses among the total ascribed to the B. rupestris group. B. villosa subsp
and individual Toc, FA and phytosterols are villosa, B. v. subsp. bivoniana, B. v. subsp. drepan-
reported in Table V. A significant positive correla- ensis and B. v. subsp. tinei can be ascribed to the B.
tion between T-Toc, γ-Toc and C 18:3 was villosa group. The B. rupestris and B. villosa groups,
observed. By contrast, a significant negative correla- B. incana and B. macrocarpa were significantly
tion between α-Toc and γ-Toc, and between α-Toc different from each other. Based on α- and γ-Toc
and T-Toc, was seen. T-FA content was positively content, B. macrocarpa was closer to the B. rupestris
correlated with the major unsaturated C 18:1, C group than to B. villosa in line with the results
18:2 and C 22:1 FA and was negatively correlated obtained using random amplified polymorphic
with the saturated C 20:0 and C 22:0 ones. DNA (RAPD) markers (Lazaro & Aguinagalde
1996). The taxa corresponding to B1, B2 and B5
form a homogeneous group, as no significant differ-
Discussion
ences were found in their Toc content. This finding
In the present study, seeds of nine wild entities of is in agreement with the classification proposed by
Brassica sect. Brassica endemic of Sicily were analy- Raimondo and Mazzola (1997), but not with the
sed to determine the Toc, FA and phytosterol assignment of brevisiliqua to the subspecific rank in
content. Cabbage, broccoli, Brussels sprouts and the B. villosa group on the basis of molecular analy-
other cultivated species of the genus Brassica have a ses (Raimondo & Geraci 2002). The data presented
putative activity against oxidative stress and may in this study confirm that different techniques can
prevent chronic diseases such as cancer, cardiovas- yield contrasting results, which cluster the species
cular disease and diabetes (Podse ˛ [ e ogon ]dek 2007). The differently.
variability observed in Toc content in B. oleracea Extensive investigations into Brassica germplasm
suggests that potential health benefits that accrue collections have shown that all the naturally occur-
with consumption of these vegetables are genotype- ring Brassica species contain high amounts of erucic