The present investigation was carried out to study the cytological effects of the herbicide racer “flurochloridone” (3-chloro-4-(chloromethyl)-1-[3-(trifluoromethyl)= phenyl]-2-pyrrolidinone) on Allium cepa with respect to the cell response, mitotic index, mitotic abnormalities and chromosome aberrations. The roots of bulbs were treated with the following concentrations depending on the root growth inhibition test: 80 ppm (LD₅₀), 40 ppm (LD_50/2) and 20 ppm (LD_50/4). The results indicated that flurochloridone herbicide reduced the mitotic division in A. cepa as compared to their control groups. The reduction in mitotic activity was more significant when the concentration of the herbicide increased and the exposure time was prolonged. The treatment conducted with flurochloridone induced a significant percentage of abnormal mitosis. Seven types of abnormalities were recorded: C-metaphase, laggards, stickiness, bridges, fragments, multipolarity and poliploidy. Micronucleated cells were also observed at interphase. In additon, in pretreated root tips, chromosome breaks, fragments and sister union were detected.

Tobacco leaf disc explants were inoculated with Agrobacterum tumefaciens strain GV2260 carrying p35S GUS-INT to determine the influence of different co-cultivation temperatures (18 – 26 °C), periods (24 – 96 h) and media (solid and liquid) on transformation efficiency. Kanamycin-resistant shoots developed on leaf discs inoculated with Agrobacterium after 4 weeks of culture initiation. Regenerated shoots were excised and rooted in the basal medium supplemented with 100 mg dm ⁻³ kanamycin and 250 mg dm ⁻³ augmentin. The rooted plantlets were finally transferred to compost and confirmed by GUS assay and PCR analysis. The highest transformation frequency was achieved from the explants co-cultivated with A. tumefaciens in liquid medium for 48 h at 22 or 24 °C.

ISHS II International Symposium on Saffron Biology and Technology IN VITRO MICROPROPAGATION OF SAFFRON