Page 5 - Geraci -Schicchi - 2002

Flora Mediterranea 12 2002 IRI

Discusslon and conclu ion

Scilla autumnali:. is a polyploid complex occurring 111 Centrai - Europc and
Mcditerranean area.
Poliploidy can become a positive cvcnt in wild populations. whcn it is accompanied
by othcr gcnetic-evolutionary processes increasing the adaptative ability (Stebbins 1971 ).
Thereforc polyploid radiation from the relevant diploids and their subsequent spreading
could be corrclared ro their adaptative response to ditferent ecological conditions in both
shon and long periods.
Wht!n a polyploid complcx rcachcs a successfull evolutionary tage. the occurrcncc of
diploid ancestors numcrically dccrcases in the whole geographical rangc up to extintion
( Favargcr l 984 ).
C'oncerning Sicily, S. t mt111111111li.\' mostly appears diploid, thcrcforc this region could be
placcd in thc geographic contcxt of south-east rnediterrancan basi n in which diploids are
mosr frcquent. On the othcr hand. thc occurrcnce of polyploids shows the possible corre-
lati an bctwcen Sicily and the central-south European area wherc polyploid populations are
more frequent.
A· for the sympat.ric occurrcncc of both diploid and polyploid chromosome races of S.

a

I O~m

c: d

Fig. 3 Mitotic mc:taphase platc~ of S. tmllunnali.\. a) M. Catalfano 2n- 14: b) Favignana ln- 14 "' l
B; c) Marianopoli ln 28: d) Belvedere ln = 42 (scale bar IO J.Jm).