Page 5 - Geraci_Schicchi_1991
P. 5
Flora Meditcrranea 12 - 2002 IRI
Discusslon and conclusio n
Scilla (l//fl/nlllaiis is a polyploid complcx occurring in Centrai - Europe and
Mcdi tcrranean arca.
Poliploidy can bccome a positive cvcnt in wi ld populations. when il is accompanicd
by olhcr genclic-evolutionary processes increasing Ihe adaplalive abi lity (Slebbins 197 1).
Th ~ rcforc polyploid radialion from the relevant diploids and thcir subscqucnl sprcad ing
could be corrclatcd IO Ihcir adaplativc response IO diffcrent ecological conditions in bolh
short and long pcriods.
When a polyploid complex reaehes a succcssfull cvolutionary stage. the occurrencc of
diploid anccstors nU11lcrically decrcases in the whole geographical range up (O exlintion
(Favarger 1984).
Concerning Sic ily, S. mlll/Jl/lwlis moslly appcars diploid, Iherefore thi5 rcgion could be
placcd in thc geographic contexl 01' soulh-casi medilerranean basin in whieh diploids are
moSI frequ crlt. On tne other hand. the occurrcnce or polyploids shows (he possi ble corre-
lalion belwecn Sici ly lInd tlle (entral-somh European area where polyploid popul:nions are
more freq uenL
As for the sympatric occurrcnce of both diploid and polyploid chromosomc races of S.
a•
10,..m
d
Fig. 3 Mitolic melaphase plalcs of S. 1lII1rmlllali.~. a) M . Catalfano 111 -= 14: b) Favignana b, " 14 + I
B; c) Marianopoli 1,, " 28; d) Belvedere 111 = 42 (scale bar IO ,..m).
