Studies were conducted to determine the effects of ethylene and anti-ethylene treatments on postharvest life of cut 'First Red' rose flowers. Effects of exogenous ethylene at 1, 10 and 100 µl l-1 for 48 h at 22 °C on cut 'First Red' rose flowers were investigated. Ethylene at different concentrations reduced postharvest life, with 100 µl l-1 having the greatest effect. Ethylene production measurements suggested that 'First Red' rose is climacteric during senescence. Pre-treatment of 'First Red' rose flowers with 0.5 mM silver thiosulfate (STS) for 2 h at 22 °C increased vase life, but pre-treatment with 1 µl l-1 1-methylcyclopropene (1-MCP) did not. Pre-treatment of 'First Red' rose with 0.5 mM STS and, to a lesser extent, 1 µl l-1 1-MCP for 2 h at 22 °C, protected flowers from subsequent exposure to 10 µl l-1 ethylene. Maximum vase life in both ethylene-treated and non-ethylene-treated 'First Red' rose flowers was obtained with 0.5 mM STS.

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In order to produce an autotetraploid population of Lilium regale, different concentration of colchicine was used as chemical mutagen treatment to induce in vitro polyploidy. Bulb scales were soaked in various filter sterilized colchicine solutions (0.01, 0.05 and 0.1%) for 6, 12 and 24 h separately, then bulb scales were shifted to colchicine free MS medium for regeneration and normal growth. The ploidy level of the regenerated plantlets from treated bulb scales was estimated by chromosome counting in root tips. However, the length of stomatal guard cell, density and chloroplast number guard cell used as cytological parameters to compare between diploid and polyploid plantlets. The results of the experiment showed that high tetraploid plantlets (27.3%) were produced by 0.01%+ 24 h colchicine treatment. However, the highest survival rate (72%) was observed in 0.01%+ 6 h colchicine treatment. The stomatal number was reduced significantly (p≤0.01) in tetraploid compared to diploid. The result of the evaluation revealed that an increase in the length of stomatal and chloroplast number guard cell was found in polyploid plantlets as well as a reduction in stomatal number per unit area. It is found that colchicine at rate 0.01% for 24 h was the most effective treatment in inducing polyploidy in L. regale plantlets.