Results 191 to 200 of about 2,327 (226)

Binarization method for chromosomal analysis of primitive plants: the case of Zamia tolimensis and Zamia huilensis (Cycadales, Zamiaceae)

Optical Engineering + Applications, 2021
Cytogenetic studies of plants allow integration with taxonomic and systematic data for the formulation of conservation strategies. However, traditional methods of microscopy image analysis for chromosome observation and identification are inefficient in ...
Alfredo Torres-Benítez, Mariana Aldana, M. Forero   +2 more
semanticscholar   +1 more source

Karyotype evolution by centromeric fission inZamia (Cycadales)

Plant Systematics and Evolution, 1984
The chromosome numbers of several species ofZamia from Mexico are reported.Z. paucijuga, distributed from central Oaxaca to Nayarit, has been found to have 2n = 23, 25, 26, 27 and 28. 2n = 28 is the highest chromosome number yet found in the cycads. Karyotypes of this species differ principally in the number of telocentric and metacentric chromosomes ...
MORETTI, ALDO, SABATO S.
openaire   +2 more sources

RADIAL GROWTH IN THE CYCADALES

American Journal of Botany, 1980
The development of radial growth which leads to the pachycaulous form was investigated in eight of the 10 genera of the Cycadales; i.e., Ceratozamia, Cycas, Dioon, Encephalartos, Macrozamia, Microcycas, Stangeria, and Zamia. In all taxa, development of radial growth is essentially the same: a primary thickening meristem is differentiated in the stelar ...
openaire   +1 more source

Critical review of morphological trait assessment in cycad (Cycadophyta: Cycadales) taxonomy: Importance of consistency and need for standardization

Phytotaxa
Taxonomic treatments within the Cycadales are largely based on gross morphological traits. Inconsistent trait assessment can adversely affect the understanding of species and relationships among them.
Jody L. Haynes
semanticscholar   +1 more source

Authoritative glossary, universal trait order, and standardized checklists of taxonomically informative traits for the extant Cycadales

Phytotaxa
Changing rules of botanical nomenclature, varying quality of species descriptions, and inconsistent use and assessment of morphological traits and the terms used to describe them have long contributed to confusion in cycad taxonomy.
Jody L. Haynes
semanticscholar   +1 more source

Somatic Embryogenesis in the Cycadales

1995
The cycads (Fig. 1) constitute remnant species of an ancient class of gymnosperms, the cycadophytes, that evolved from the free-sporing progymnosperms, which also gave rise to the coniferophytes. According to Gifford & Foster (1989), the cycadophytes have included 3 orders of plants, the extinct Cycadeoidales and Pteridospermales (seed ferns), that are
Richard E. Litz, Victor M. Chavez, Pamela A. Moon   +2 more
openaire   +1 more source

Zamia urarinorum (Cycadales, Zamiaceae), a new cycad species from wetland forests of Loreto, Peru

Phytotaxa
We describe and illustrate Zamia urarinorum, a new species of arborescent cycad from wetland forests in the Tigrillo and Urituyacu river basins of Loreto, Peru.
Michael Calonje, Ricardo ZÁRATE-GÓMEZ, Malcolm A. Jones, R. Segalla, M. Brañas, C. G. H. Pizango, Fernando Roca Alcázar   +6 more
semanticscholar   +1 more source

General Traits of the Cycadales

1990
Vegetative Morphology and Anatomy. Notable contributions to the study of cycad morphology were made by Chamberlain (1919, 1935 and numerous other publications) and his students. The bibliography in Read and Solt (1986) provides entry into the literature.
L. A. S. Johnson, K. L. Wilson
openaire   +1 more source

Genome sizes for all genera of Cycadales

Plant Biology, 2011
AbstractNuclear DNA content (2C) is reported for all genera of the Cycadales, using flow cytometry with propidium iodide. Nuclear DNA content ranges from 24 to 64 pg in cycads. This implies that the largest genome contains roughly 40 × 109 more base pairs than the smallest genome. The narrow range in nuclear DNA content within a genus is remarkable for
openaire   +2 more sources

Maternal inheritance of plastids in Encephalartos Lehm. (Zamiaceae, Cycadales)

Genome, 2001
The mode of inheritance of chloroplast DNA has been determined in Encephalartos by employing a restriction fragment length polymorphism analysis of chloroplast DNA. Artificial F1 hybrids were produced between a female specimen of E. natalensis and a male specimen of E. woodii.
CAFASSO D., COZZOLINO, SALVATORE, CAPUTO P., DE LUCA P.   +3 more
openaire   +6 more sources