The present investigations attempted to study the effects of different colour of light on seed germination, hypocotyl growth, mobilization efficiency (ME), vigor index (VI), biomass production and content of photosynthetic pigments (Chl a, Chl b and Carotenoids) in Rice (Oryza sativa L.) cv. Sugandha 5, an important staple food crop of the world. Germination rate was found maximum in red light (98%), followed by blue (94%) and natural light (93%) at 84 hours while, almost no germination was shown in green light even after 96 hours. Yellow light caused significant reduction in % germination (85). The seedlings obtained under different lights revealed variation in biomass production (fresh weight of root and shoot). Root and shoot growth were observed highest in red light and the order of biomass production was red > natural > yellow > blue > green. ME and VI of rice seedlings recorded maximum (128.22 and 43.26 respectively) in red and minimum in yellow light (116.09 and 1.20 respectively). Both, ME and VI could not be estimated under green light due to absence of well­marked hypocotyl. The contents of photosynthetic pigments in seedlings indicate synthesis of photosynthetic pigments highly dependent on light quality. Chlorophyll b and carotenoids were recorded highest in natural light whereas total chlorophyll and chlorophyll a were highest in red light in comparison to other light treatments. These findings indicate possibility for exploring light quality for manipulation of germination and seedling health of crop plants in general and O. sativa in particular.

Keywords: Germination; Light Wavelengths; Oryza Sativa; Photosynthetic Pigments; Rice; Seedling
Vigour.