Abstract:

Meiosis and mitosis of eight species of Polygonatum from Sichuan, China, were

investigated.  Ten bivalents (n=10) at meiosis of pollen mother cells were observed ih P. od-

oratum (Mill.) Druce.  Meiotic observation on pollen mother cells in P. punctatum Royle ex

Kunth shows 16 bivalents (n=16) at diakinesis, P. kingianum Coll. et Hemsl.  13 bivalents

(n=13) at diakinesis.  P. zanlanscianense Pamp. 15 bivalents (n=15) in MI, P. cirrhifolium

(Wall.) Royle 28 bivalents at diakinesis. Somatic chromosomes were observed in root tip cells.

The karyotype formulae are as follows: P. odoratum (Mill.) Druce K(2n)=20=4st+6sm+10m;

P. cyrtonema Hua K(2n)=20=6sm+14m; P. punctatum Royle ex Kunth K(2n)=32=2t+8st+

2sm+20m; P. kingianum Coll. et Hemsl. K(2n)=26=8st(2SAT)+14sm+4m; P. alternicirrho-

sum Hand.-Mzt. K(2n)=32=6st+8sm+18m(2SAT); P. zanlanscianense Pamp. K(2n)=30=

2t+6st+6sm+16m(2SAT); P. sibiricum Delar. ex Redouté K(2n)=24=2t+14st(2SAT)+6sm

+2m; P. cirrhifolium (Wall.) Royle K(2n)=56=18st+10sm+28m.   The karyotypes of P.

punctatum, P. kingianum, P. alternicirrhosum and P. cirrhifolium are reported for the first

time.

        Both the chromosome number and structure in our materials are certainly different from

thoses in previous reports.  Of numerical variation polyploidy and aneuploidy have been record-

ed, and aneuploidy is frequent.  According to degree of asymmetry of the karyotype, the 8

species are divided into three types: 2B, 3B, 2C.  The increasing asymmetry is correlated with

the increasing of the chromosome number.

      There are no obvious differences in chromosome number and karyotype between Alterni-

folia Baker and Verticillate Baker.  They are not two natural groups.  This opinion is dif-

ferent from that of Therman and Suomalainen.

Key words: Polygonatum, Chromosome, Karyotype