TITLE:
Technique to Obtain Mitotic Chromosomes of Conyza bonariensis L. Cronquist (Asteraceae)
AUTHORS:
Juliana Maria de Paula, Cecília Alzira Ferreira Pinto-Maglio
KEYWORDS:
Hairy Fleabane, Cytogenetics, Chromosomes, Weed
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.6 No.9,
June
23,
2015
ABSTRACT: Cytogenetic analysis requires cytological preparations that unequivocally reveal the chromosome number and permit optimal visualizations of chromosome morphology for the construction of karyotypes and ideograms. Chromosomal characterization is possible only by establishing these two parameters. To cytogenetically characterize the weed Conyza bonariensis (L.) Cronquist (Asteraceae), it was necessary to improve cytological analysis techniques to obtain optimal results. This species belongs to a genus whose plants have wide phenotypic plasticity. These plants can be morphologically differentiated by other types of analysis, and thus the application of this technique will serve as a reference for cytogenetical analysis of other groups of plants that have cytogenetic characteristics similar to those of C. bonariensis. The methodology described here highlights three main protocol steps: 1) root tip collection from newly germinated seed radicles and from young root tips of mature plants, 2) pretreatment of meristems with antimitotic agents, both isolated and combined, and 3) acid and enzymatic hydrolytic processes.