In- vitro Phytotoxic Effects of Cadmium on Morphological Parameters of Allium cepa.

The aim of this study is to investigate the phytotoxic effects of Cadmium (Cd) on germination and the early seedling growth of Allium cepa in the Faridabad district, India. The cadmium poses a major threat to agriculture and human health. Seeds of three different onion cultivars were exposed to five different Cd concentrations (20; 40; 60; 80 and 100 ppm). The germination percentage, germination index and growth parameters such as plumule and radical growth were compared to the untreated seeds. The inhibitory effects on the germination of onion seedlings and the inhibition was observed at 80 ppm and 100 ppm. The increased concentration of cadmium is directly proportional to the inhibitory effects on the seedling germination, and the root and shoot length of Allium. Pusa Ridhi performed better under Cd stress, while Pusa Madhavi had poor performance. Later, there had been a maximum decrease in seedling length (3.97 %), germination percentage (53.33 %) and the germination index (1.353%) at 100 ppm. Tolerance index varied among the onion cultivars; maximum tolerance index was observed in Pusa Ridhi followed by Pusa Red and Pusa Madhavi. From these results, it is evident that Pusa Ridhi could germinate effectively in soils contaminated with Cd, however, further studies are needed to signify its effects on the growth and yield of onions. [ABSTRACT FROM AUTHOR]