Chromosome stability in crypreserved germplasm of Cyrtopodium hatschbachii Pabst (Orchidaceae)

SURENCISKI, M.; DEMATTEIS, M.; FLACHSLAND, E.

Annales Botanici Fennici

Finnish Zoological and Botanical Publishing Board

Lugar: Helsinski; Año: 2007 p. 287 - 292

0003-3847

Cyrtopodium hatschbachii is a recently-described orchid distributed in northeastern Argentina. The natural populations of this species require special attention as regards as their conservation because they have very restricted size and distribution, and are in danger for the extractive action by local people. The cryopreservation of relevant plant genetic resources in liquid nitrogen (LN) is the most commonly applied technique because of the low space requirement and the absence of contamination. Genetic stability should be considered in any cryopreservation processes. Chromosome number and morphology are the primary cytogenetic parameters that should be stable after cold storage. We analyzed cytogenetically plants of this species in order to determinate its stability level. Twenty in vitro plants obtained from cryopreserved seeds and 20 in vitro plants obtained from seeds without cold treatment were examined. The results showed that no changes occurred in chromosome number, but significative differences (P¡Ü0.05) in chromosome size and centromeric index were observed. This results suggest a state of less condensed chromatin in the cryopreserved material during the first stages of development. The chromosome number and karyotype analysis of Cyrtopodium hatschbachii, is also presented for the first time.