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CHROMOSOME COUNTS, CYTOLOGY, AND REPRODUCTION IN THE CACTACEAE
Author(s) -
Ross Robert
Publication year - 1981
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1981.tb07790.x
Subject(s) - biology , polyploid , meiosis , ploidy , chromosome , reproduction , zygote , sexual reproduction , mitosis , metaphase , feulgen stain , interphase , botany , genetics , evolutionary biology , embryo , embryogenesis , gene , dna
Chromosome counts and observations of reproduction for 55 taxa of Cactaceae indicate that polyploidy is correlated with self‐fertility, adventive embryony, profuse branching, and vegetative reproduction. Six genera ( Blossfeldia. Cleistocactus, Frailea, Pelecyphora, Rebutia , and Strombocactus ) and 35 species or varieties are reported here for the first time. Preliminary observations of pachytene and diplotene indicate that these stages may be more useful in chromosome recognition than mitotic stages. Secondary association at metaphase I and II is interpreted as a retention of homologue association at interphase I and II (interkinesis). During meiosis of certain species, Feulgen negative bodies are present. The production of an abnormal premeiotic division is suggested as a mechanism for polyploid origin.