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Morinda citrifolia Linn. (family Rubiaceae) is a small tree occurring in tropical areas of the world. The plant contains several medicinally active components that exhibit the therapeutic effects such as antibacterial, antiviral and anticancer activities. Anti-genotoxic effects of aqueous extracts prepared using dried leaves of M. citrifolia was studied. Allium cepa root tip meristem cells treated with 7% hydrogen peroxide were used for eliciting antigenotoxicity. For this purpose experiments were performed with A. cepa onion bulbs treated for 24 h with different concentrations (15 or 30 g/L) of aqueous extract with or without pre-treatment (1 h) with 7% hydrogen peroxide. A significant reduction in mitotic index was recorded in treatment groups over negative control. Chromosomal aberrations such as breaks, bridges, stickiness and polar deviations were observed in positive control and treatment groups. The highest (21.48) percentage of chromosomal aberrations was noticed in positive control. A significant reduction in chromosomal aberrations (9.39) was recorded in root tips treated with hydrogen peroxide followed by 15 g/L extract. H 2 O 2 induced chromosomal aberrations were reduced due to leaf extract treatment indicates antimutagenic potential of the M. citrifolia. The observations suggest that M. citrifolia aqueous leaf extracts have antimitotic and anti-genotoxic effects; consequently oxidative stress induced aberrations due to H 2 O 2 are efficiently restored in the extract treated A. cepa root meristem cells.

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The seeds of Elaeocarpus serratus, a tropical underutilized fruit tree are characterized by hard seed coat and consequent poor water uptake and low germination. To improve the regeneration through seeds, various parameters such as viability of seeds, water uptake, and effect of seed mass on germination and pretreatments were performed using a completely randomized design (CRD). Tetrazolium (TZ) test was conducted using fresh, mature seeds revealed 50 ± 2.56% mean viability. Seeds of different weight classes showed similar pattern of water uptake and the saturation level was achieved at 60 hrs of soaking. Seeds belong to weight class 2.6-3.5g were germinated (12.5 ± 1.26%) with 175 ± 1.75 days (d) of mean time taken for germination (MTG). Germination capacity of seeds varied significantly among different populations and Varkala population gave 12.5 ± 1.1% germination with 174.6 ± 2.5 d MTG. Among various seed treatments, mechanical scarification was superior in germination and significant reduction in MTG (p 0.05). The mechanical scarification by complete removal of seed coat resulted in 49.2 ± 1.52% germination within a short period of time (9.52 ± 0.89 d MTG). However, the complete removal of seed coat without damaging to embryo is a difficult task. An alternate treatment (Mechanical scarification II) by making cracks on nut faces vertically followed by soaking in distilled water for 24 hrs gave 48.4 ± 1.73% germination with significantly reduced MTG (12.14 ± 0.56 d) over unsoaked, untreated control (6.5 ± 1.84% germination and 197.18 ± 1.79 d MTG; p 0.05). This treatment (Mechanical scarification II) is therefore recommended for E. serratus seeds as it can adopt easily and can achieve 7 fold increases in germination over control. The recorded germination through mechanical scarification is in tune with realized viability percentage of the seeds.

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