KARYOTYPE STUDIES OF CULTIVATED TOBACCO

Karyotypes of 10 cultivars of 6 cultivated forms in two cultispecies of Nicotiana(N.tabacum and N.rustica) were studied.All of the experimental materials are amphidiploid.The karyotypes formulae of N.rustica cv.'Chrysanthemum tobacco' is Zn 4x=48=44m(2 SAT) +4 sin.The karyotypes of 9 cultivars of N.tabacum can be simplified as follows: cv.'Baihuatiegan' 2n=4x=48=34m + 10 sin (2 SAT ) + 4 st; cv.'Liuyejian' 2n=4x=48=34m+10 sin+ 4 st;cv.'NC 89' 2n=4x=48=30 m(2 SAT)+ 12 sin+ 6st;cv.'Maryland 609' 2n=4x=48=36 m+ 10 sin+Zst;cv.'Havana 211' Zn= 4x= 48 = 32 m + 12 sin (4 SAT) + 4 st;cv.'Cigarro wrapper-Indonesia' 2n=4x=4838 m+8 sin+2 st;cv.'Burley 21' 2n=4x=48=32m+12sin+4 st icy.'Sumsum' 2n=4x=48=34m+12sin (2SAT) + 2st; cv.'Aromatic tobacco-Thailland' 2n=4x=4834 m+ 12 sin + 2st.