Comparative germination study between some native and invasive weed species in Nigeria

The ability of seeds to germinate under a broad environmental gradient is capable of increasing their chances of colonization. The germination of some native and invasive species were examined with a view to understanding some aspects of their biology. Mature seeds of the selected species were collected from natural populations, sterilized and placed in 9 cm diameter Petri dishes lined with moist double-layer filter papers at room temperature in five replicates. The seeds of species showing dormancy were broken by scarification at different time intervals. Independent sample t-test was used to compare the means of the germination percentages between native and invasive species. Two way analysis of variance was used to compare the means of the germination percentages using species and time as factors in one instance and status and time as factors in another instance. Seed germination percentage did not significantly differ between the invasive and native species when distilled water was used (t = 0.28; df = 8; p = 0.78), but significantly differed among invasive (F-(4,F-20) = 28.81; P < 0.0001) and native species (F-(4,F-20) = 204.97; p < 0.0001). After pretreatment, germination percentage differed significantly among all species (F-species = 9.35; p < 0.0001) and between invasive and native species (F-status = 5.22; p = 0.04). This study concluded that the selected invasive species had more capability to germinate under acidic conditions compared to native species, although germination did not differ significantly between them under normal conditions.