J Syst Evol ›› 1991, Vol. 29 ›› Issue (6): 511-516.

• Research Articles • Previous Articles     Next Articles

Variation and Phylogenetic Relationships Between Polygonatum odoratum and P. cyrtonema

Wang Jin-Wu, Li Mao-Xue, Yang Ji   

  • Published:1991-11-10

Abstract: The present paper is a report on combined cytological and taxonomical studies of Polygonatum odoratum and P. cyrtonema. Based on the extensive field observation and mass collection for some years, the authors made a detailed comparison of the variation pattern of morphology、cytology as well as geographic distribution between forms of P. odoratum and P. cyrtonema. The results show that: Form I: Stem angular, leaves elliptic, peduncles with one, rarely two flowers, perianth 1.7-2.0 cm long, stamens adnate to perianth in the middle part or a little lower. The karyotype formula is 2n=20=12m+8sm (2SAT); Form II: Stem angular, leaves narrow-oblong, peduncles with 2-3 flowers, perianth 2.8-3.2 cm long, the position of stamens on perianth is above the middle part. It has the karyotype 2n=20=8m+1osm(4SAT)+2st; Form III: Stem terete, leaves oblong-lanceolate, peduncles with 3- 10 flowers, perianth 1.5- 2.0cmlong, stamens are adnate to perianth also above the middle part. In this form, two kinds of karyotypes are found: 2n = 22 = 6m+8sm+8st and 2n = 20 = 4m+6sm (2SAT) +10st; Form IV: Stem terete, leaves elliptic, peduncles with 1-4 flowers, perianth 2.3-2.8 cmlong, stamens adnate to perianth above the middle part. The karyotype formulae are 2n = 20 = 4m+14sm (2SAT)+2st and 2n = 20 = 10m+10sm (2SAT); Form V: Stem terete, leaves oblong-lanceolate, peduncles with 3-5 flowers, perianth less than 2.0cm long, stamens adnate to perianth above the middle part. It is of the karyotype 2n=22=4m+8sm(2SAT) +10st. It is pointed out that the P. odoratum collected from the Qinling Range may be a hybrid or an intermediate in the evolutionary process from P. odoratum to P. cyrtonema. The differences between the different forms of P. cyrtonema are obvious and stable, and are probably derived from the chromosomal variation. The different forms of P. cyrtonema may have evolvedfrom P. odoratum along different courses.

Key words: Polygonatum odoratum, P. cyrtoncma, Variation, Evolution