Intraspecific karyomorphological and genome size variations of in vitro embryo derived Iranian endemic Asafoetida (Ferula assa-foetida L., Apiaceae)

Abstract

Asafoetida (Ferula assa-foetida L.) is one of the endemic medicinal plants in Iran. Analysis of karyomorphology and 2Cx DNA measurements (monoploid genome size) of 18 Iranian endemic Ferula assa-foetida populations were performed. The in vitro embryo-derived root tips were examined for karyological studies, via technique of squash and stain with 2% (w/v) aceto-orcein. Seeds of the Ferula samples and leaves of Solanum lycopersicum as standard reference (2C DNA = 1.96 pg) were stained with propidium iodide (PI), using flow cytometric (FCM) technique. All the studied populations were diploids (2n = 2x = 22) with mean chromosome length (CL) of 3.95 μm, varied from 3.05 μm (P7) to 4.94 μm (P18). The mean total chromosome volume (TCV) was 0.98 μm3, ranged from 0.47 μm3 (P7) to 1.57 μm3 (P3). Two-typed chromosomes (“m”, “sm”) formed three classes of karyotype formula. Karyotypes were mostly symmetrical and fell in 1A and 2A Stebbins category. The monoploid genome size of Iranian endemic Ferula assa-foetida populations is being stated for the first time; its mean value was 4.51 pg, ranged from 4.09 (P4) to 4.69 pg (P16). Intraspecific karyomorphological and genome size variations were clearly confirmed in studied Ferula assa-foetida.