Morphogenetic and photosynthetic pigments alteration of Black gram [Vigna mungo (L.) Hepper] influenced by gamma irradiation

The present investigation was conducted to determine the gamma irradiation effect on growth characteristics and photosynthetic pigments in black gram (Vigna mungo L. Hepper) variety VBN-4. Various doses of gamma rays were tested to induce mutation in black gram seeds at 20, 40, 60, 80, 100 and 120kR. Gamma radiation (γ) induced morphological changes such as plant height, stem and root length. Fresh and dry weight was decreased with increased doses compared to control. While studying the photosynthetic pigments, the chlorophyll a and b were decreased. However, carotenoid contents were increased at an increasing dose of gamma-ray treatment compared to control. Fluorescence spectroscopical(F685) studies revealed that reduction of chlorophyll (Chl) contents and increased peak intensity were obtained due to chlorophyll damage which is directly correlated with increasing doses of gamma radiation. On the other hand, the photosynthetic damage by gamma radiation was phenotypically expressed as yellowish leaf coloration at 60kR and light green was observed at higher doses (100 kR). The chlorophyll-associated protein profile by SDS-PAGE showed polymorphic band pattern in higher doses.The present results confirm that the inhibitory effects of gamma irradiation on plant growth and photosynthetic pigment damage depend on the exposure of gamma rays. Hence, the present investigation helps understand the gamma irradiation effects on morphological and photosynthetic damage in blackgram.