Comparative karyomorphological study between male and female plants of some Cycas and Zamia species.

This paper presents the karyotype and the idiogram of known sex plants for five species of Cycas (Cycadaceae) and seven species of Zamia (Zamiaceae). All five species of the genus Cycas had the same chromosome number (2n = 2x = 22) but their karyotype formulae varied into three groups: 10m+10sm+2st, 12m+8sm+2st and 14m+8sm. The karyotype of male and female Cycas plants could be clearly distinguished by the satellite chromosomes. All seven species of the genus Zamia varied in both chromosome numbers (2n = 2x = 16 up to 2n = 2x = 24) and karyotype formulae. It was difficult to differentiate between the male and female plants of the Zamia spp. by karyotyping because of the lack of satellite chromosomes in both sexes.

[1]  A. Levan,et al.  NOMENCLATURE FOR CENTROMERIC POSITION ON CHROMOSOMES , 2009 .

[2]  K. D. Hill,et al.  New species and a new record of Cycas (Cycadaceae) from Thailand , 2002, Brittonia.

[3]  V. Hongtrakul,et al.  Karyomorphological Study of Some Selected Cycads , 2007 .

[4]  V. Hongtrakul,et al.  Analysis of Sex Determination in Some Cycads Using Methylation- Sensitive Amplification Polymorphism (MSAP) , 2007 .

[5]  S. Sabato,et al.  Karyotype evolution by centromeric fission inZamia (Cycadales) , 1984, Plant Systematics and Evolution.

[6]  C. J. Marchant,et al.  Chromosome patterns and nuclear phenomena in the cycad families Stangeriaceae and Zamiaceae , 1968, Chromosoma.

[7]  K. Kondo,et al.  Chromosome phylogeny of Zamia and Ceratozamia by means of Robertsonian changes detected by fluorescence in situ hybridization (FISH) technique of rDNA , 2001, Plant Systematics and Evolution.

[8]  K. Kondo,et al.  A Karyotype Comparison of Nine Species of Aneuploid Zamia by Using the Conventional Orcein Staining and the Fluorochrome CMA-DAPI Differential Staining Methods , 1999 .

[9]  D. Stevenson,et al.  KARYOLOGY AND PHYLOGENY OF SOME MESOAMERICAN SPECIES OF ZAMIA (ZAMIACEAE) , 1996 .

[10]  A. Vovides,et al.  Karyotype polymorphism in the cycad Zamia loddigesii (Zamiaceae) of the Yucatan Peninsula, Mexico , 1996 .

[11]  M. Hizume,et al.  A Karyomorphological Study of Five Species and One Variety of Cycas , 1995 .

[12]  David L. Jones.  Cycads of the world , 1993 .

[13]  D. Stevenson,et al.  Intraspecific chromosome variation in Zamia (Zamiaceae, Cycadales) , 1991 .

[14]  A. Moretti.  Cytotaxonomy of cycads , 1990 .

[15]  D. Stevenson.  Chigua, A New Genus in the Zamiaceae, with Comments on Its Biogeograhic Significance , 1990 .

[16]  A. Vovides,et al.  Two New Species of Zamia (Zamiaceae, Cycadales) from Southern Mexico , 1988, Botanical Gazette.

[17]  M. Segawa,et al.  SEX CHROMOSOMES OF CYCAS REVOLUTA , 1971 .

[18]  P. Mathew,et al.  Cytological Studies in the Cycads: Sex Chromosomes in Cycas , 1962 .

[19]  C. Lee.  SEX CHROMOSOMES IN GINKGO BILOBA , 1954 .

[20]  E. H. Newcomer.  THE KARYOTYPE AND POSSIBLE SEX CHROMOSOMES OF GINKGO BILOBA , 1954 .

[21]  C. J. Chamberlain.  Two New Species of Zamia , 1926, Botanical Gazette.

[22]  C. E. Allen.  A CHROMOSOME DIFFERENCE CORRELATED WITH SEX DIFFERENCES IN SPHAeROCARPOS. , 1917, Science.