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tion. The strong depletion of starch coincides with
the formation of stachyose and an increase in
sucrose when desiccation tolerance is achieved, as
in B. campestris (Leprince et al., 1990), or utiliza-
tion of starch and soluble sugars for the synthesis of individuals in a population. This may explain the
storage oils, proteins and other seed components, as
in B. napus (Norton and Harris, 1975). The accu-
mulation of storage lipids showed the same pattem
as that of proteins in B. napus (Fowler and Downey,
1970; Norton and HatTis, 1975). Depositian of star-
age proteins is at a maximum just before complete
drying. SDS-PAGE gels showed that B. macra-
carpa reserve proteins have molecular weights of
21 , 22, 27 and 30 KD with a pattern similar to the
main bands of proteins reported for Brassica napus
with molecular weights between 20 and 32 KD
(Crouch and Sussex, 198 1).
The column present in mucilaginous cells of B.
macrocarpa was observed in Brassica gravinae
(Stork et al. , 1980) and in other Cruciferae such as
Diplotaxis and Lobularia maritima (Vaughan et al.,
197 1); mucilages are also present in seeds of some
Brassicaceae (Vaughan et al.,197 l ) and Sicilian
Brassica species belonging to the B. rupestris-vil-
losa complex (Scialabba and Raimondo, 1995).
The function of the seed mucilage is stili contro-
versia!, its main role being reported as adhesion to
animals or soils, regulation of germination with
water retention and a barrier to oxygen (Johry,
1984). There is no previous literature on the pres-
ence of enzymes in mucilage cells. Esterases and
acid phosphatases in the mucilage of B. macra-
carpa may ha ve an enzymatic function to start the
germination process as the seed imbibes, or may
play a role in seed-soil interactions sim ilar to that ic development. Bulg. Genetic Selek (Sofia) Il, 201-205.
of hydrolytic enzymes present on the root surface.
The acid phosphatase of roots, as detennined in
vivo, is an ectoenzyme secreted or released by the
root, particularly in the apical zones (Dinkelaker
and Marschner, 1992). The activity of this acid
phosphatase determines the hydrolysis of organic
phosphorus (Marschner, 1997) and increases in
response to phosphorus deficiency (Helal and
Dressler. 1989; Todaro and Sakai. 1991). In line
with this role, acid phosphatase activity in seed
mucilage is important when seeds germinate in
soils with a low phosphorus content.
These results suggest that the enzyme pattern dur-
ing the development of B. macrocarpa is impor-
tant for correct seed germination and reproduction.
If this pattern is modified by endogenous or envi-
ronmental factors during seed development, the
vigour and germinability of seeds may be
impaired, leading to a reduction in the number of
threatened status of the B. rupestris- villosa com-
plex.
ACKNOWLEDGEMENTS
This work was fi nanced by a grant from MURST
60%. The authors wish to thank Prof. P.B. Gahan
for helpful suggestions and criticai reading of the
manuscript.
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