br Materials and methods br Results and discussion

Materials and methods

Results and discussion
Nanotechnology has emerged as a new discipline, and nanoparticles have become a centre of attraction for researchers because of its unique physico-chemical properties compared to their bulk particles (Monica and Cermonini, 2009). Silica nanoparticle acts as a delivering agent that delivers DNA and chemicals into plants as well as animals cell and tissue (Torney et al., 2007). However, the mode of action of nanoparticles on plant growth and development is still too scarce. As we know seed germination provides a suitable foundation for plant growth, development and yield. In the present experiment application of nSiO2 enhanced seed potential by increasing the characteristics of seed germination (Figs. 3A, B and 4A, B). Parameters of seed germination were increased with increasing levels of nSiO2 up to 8gL−1. Among the treatments, application of 8gL−1 of nSiO2 proved best by giving the highest values for percent seed germination, germination mean time, seedling vigour index and seed germination index. Application of 8gL−1 of nSiO2 increased percent seed germination by 22.16%, germination mean time by 3.98%, seedling vigour index by 507.82% and seed germination index by 22.15% over the respective controls. These results agree with the findings of Nair et al. (2011). They observed better germination of seeds of rice in the presence of FITC-labelled silica nanoparticles. Also, the improvement in germination characteristics of seed as a result of nSiO2 demonstrated that it may act like a bulk particle of silica, which calls for more research on its involvement into the mechanisms of seed germination. An increase in germination may be due to the guanylyl cyclase and utilization of nSiO2 by seeds (Suriyaprabha et al., 2012a). Data presented in Fig. 5A and B reveal that the application of nSiO2 had a significant effect on seedling fresh weight and dry weight. Seedling fresh weight and dry weight increased with increasing levels of nSiO2 up to 8gL−1. Application of 8gL−1 of nSiO2 increased seedling fresh weight by 116.58% and seedling dry weight by 117.46% over the respective controls. Suriyaprabha et al. (2012b) reported that nSiO2 significantly enhanced plant dry weight, and also observed enhanced levels of organic compounds such as proteins, chlorophyll and phenols in maize plants treated with nanosilica. Thus, on the basis of the roles played by nSiO2, we could easily visualize their direct and indirect involvement in the root and shoot growth (Fig. 2) by better improvement in seed germination characteristics (Figs. 3A, B and 4A, B).

Conclusion
In conclusion, these results of the current study reveal that the application of nSiO2 significantly enhanced seed germination potential. Application of nSiO2 improved percent seed germination, mean germination time, seed germination index, seed vigour index, seedling fresh weight and dry weight. An increase in germination parameters by the application of nSiO2 may be effective for the growth and yield of crops. However, the present experiment invites researchers to find out the interaction mechanism between nanosilica and plants which estabilishes that nSiO2 could be used as a fertilizer for the crop improvement.

Acknowledgement
The financial support by the Deanship of Scientific Research of King Saud University, Riyadh, KSA, to the Research Group No. RGPVPP-153 is gratefully acknowledged.

Introduction
According to the report of food and agricultural organization of United Nations, India is third among top fishing countries behind China and Indonesia in terms of quantity produced. Despite major proportion is being used for human consumption, a considerable quantity is wasted or directed toward non-food products from the global fish production (FAO yearbook, 2010). Every year, a huge quantity of fishery wastes and by-products are generated by fish processing industries. Either these marine wastes are underutilized to produce low market value products such as fish meal, fish oil, fertilizers or simply dumped leading to environmental issues (Quaglia and Orban, 1987; Gildberg, 1993). The major quantity of solid wastes discarded from seafood processing plants are in the form of fish head, viscera, skin, bones, frames, and some muscle tissue (Awarenet, 2004). Complete utilization of fishery wastes for recovering high-end products would be the fruitful strategy to overcome the issue and increase the economic gain. Fishery wastes and by-products are valuable sources of raw material for recovery of bioactive compounds. The discarded wastes are rich sources of protein that can be made use in various commercial and industrial applications. The fishery wastes converted by proteolytic hydrolysis into a more marketable and functional form are called as fish protein hydrolysates. Production of fish protein hydrolysates by enzymatic degradation is a significant research arena of recent past. The fish protein hydrolysates thus produced are widely used as nutritional supplements, functional ingredients, and flavor enhancers in food, beverage and pharmaceutical industries (Je et al., 2008).