Assessment of seed quality parameters and effect of physical and chemical treatments on seed germination of Myriophyllum Spicatum L.

The present study was undertaken to understand the fruit and seed morphology, seed viability andeffect of various physical and chemical factors on seed germination allowing us to explore thespread potential and/or seedling recruitment mechanism in Myriophyllum spicatum L.. The fruit ofthe species is a schizocarp, while as seed is a nutlet. The seed set was recorded to be ranging from70.98-77.91% across the standing water populations, whereas no seed set was observed in runningwater populations due to the lack of an effective pollination system. The seed viability ranged from85-90%. For in-vitro seed germination studies, the seeds were subjected to different physical andchemical treatments under alternate light and dark as well as continuous dark conditions. Theseeds in control and those treated with different concentrations of GA3 and IAA and those whoseepicarp and mesocarp were removed did not show any signs of germination. However, it wasobserved that surgical exposure of the embryo (cutting of hard endocarp of seed) has a promotereffect on germination and maximum percentage germination (76.66 ± 5.77) was recorded due tosurgical exposure of embryo plus different concentrations of GA3. Moreover, a good germinationpercentage was recorded in seeds subjected to chilling treatment. Further, it was observed thatseed germination of one-year-old seeds was less if compared to the current year seeds and overallpercentage germination was higher in alternate light and dark if compared to continuous darkconditions in all the treatments.Thus, we conclude that the dormancy of the seeds is due to thehard endocarp and that the light has a promoting effect on germination. With the increase in theage of the seeds, there is decrease in their viability and hence germination. The chilling wintertemperature of the Kashmir is responsible for breaking the hard endocarp of the seeds leading totheir germination and hence spread of the populations.