ABSTRACT

An experiment was conducted to study the effect of two chemical mutagens on the morphological characteristics of waterleaf (Talinum fruticosum Jacq. Wild). It was carried out during the dry season in 2017 and 2018. It was a pot experiment laid out with two types of planting materials, seeds and stem cuttings, each treated with two chemical mutagens; ethanol and formalin. The seeds and stem cuttings of the plant were soaked in solutions of different concentrations of formalin and ethanol at: 0.3, 0.6, 0.9, 1.2 and 1.5% for thirty minutes, except the control. It was a 2x2x6 factorial experiment laid out in a Completely Randomized Design (CRD) with three replicates, twenty four pots per replicate and seventy-two pots in all. The highest germination and sprouting percentages were recorded for the control followed by 0.3% and 0.6% of both ethanol and formalin during 2017 and 2018. Reduced germination percentage was recorded for seeds treated with ethanol and formalin at higher concentrations. The tallest plant mean was recorded for formalin at 0.3% concentration but was not significantly different from the control at p< 0.05 during both years. Increased number of leaves per plant was recorded for stem cuttings treated with ethanol at 0.3 and 0.6%, formalin at 0.3% and also seeds treated with ethanol at 0.6 and 0,9% and they were significantly different from the control at p< 0.05. Mean leaf area value recorded for ethanol treated seeds at 0.3 and 0.6% and stem cuttings at 0.3% were significantly different from the control at p< 0.05. Leaf length recorded in seeds treated with 0.3% ethanol, Stem cuttings treated with 0.6 and 0.9% formalin was significantly longer than the control at p< 0.05. Stem cuttings treated with formalin at 0.3% recorded the highest leaf yield for both years and it was significantly different from the control at p< 0.05. Number of branches recorded for stem cuttings treated with ethanol at 0.3% concentration level was significantly different from the control at p < 0.05. For formalin, control plant had the highest number of branches and was significantly different at p < 0.05 from the other concentrations in 2017 and 2018. A high stem circumference value was recorded for seeds and stem cuttings treated with ethanol and formalin at 0.3% concentration but they were not significantly different from the control at p < 0.05 in 2017 and 2018. Reduction in plant height, number of leaves, stem circumference, leaf length, number of branches and leaf area was observed at higher concentrations of both ethanol and formalin in both planting materials. Reduction in the traits under study was more pronounced under formalin treatment than ethanol. The present study demonstrated that seeds and stem cuttings treated with both formalin and ethanol at lower concentrations (between 0.3- 0.6%) could affect the morphological behaviour of the waterleaf plant.