ABSTRACT
PURPOSE: To study the effects of gamma radiation on tea seed germination, morphological changes, and genetic variation by using gamma radiation. MATERIAL AND METHOD: Fresh Tea seed material were irradiated with twenty different doses of gamma radiation such as 0, 2, 4, 6, 8, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80 90, 100, 200, 500 and 1000 Gy from Cobalt 60Co source from Regional Nuclear Agriculture Research Center, Bidhan Chandra Krishi Viswavidyalaya (BCKV), West Bengal, in between 2019 and 2020. RESULT AND CONCLUSION: The growth behavior of tea seedling was recorded under varying levels of gamma radiation and its performance at nursery stages. It was observed seed irradiated with doses from 35 Gy to 100 Gy could germinate but could not survive beyond five (05) months. When treated with higher doses as 200 Gy, 500 Gy and 1000 Gy, no seed germination takes places due to possible damages occur in the DNA structure. Screening of growth characteristics of tea plant generally monitored by the characteristics like plant height, number of leaves, number of primary branches, base diameter, and total leaf area of plants and we found that these characteristics significantly increased with the progress of time and increasing levels of gamma radiation; however, the plant height showed decreasing trend with the increasing levels of gamma radiation, which could be due to the change in chromosomal structure and genetic alteration. After 90 weeks of planting, the plant height, no. of primary branches, the number of leaves, plant base diameter, and total leaf area per plant recorded were 36.42 cm, 1/plant, 7.11/plant, 0.62 c.m, 22.92 cm2/plant respectively under the radiation level 30 Gy, whereas the corresponding figures of the above parameters at the control treatment were 85.32 cm, 1/plant, 18.84/plant, 1.18 c.m and 26.68 cm2/plant, respectively. The total plant height, no. of primary branches, the number of leaves, plant base diameter, and total leaf area per plant were significantly influenced by the rising levels of gamma radiation (up to 100 Gy), finally, after 90 weeks of planting, the maximum no. of branching was observed in the treatment of 8 Gy, 10 Gy and 15 Gy respectively. The study reveals a hitherto open the possibility of using gamma radiation on tea plant for creation of variation in the tea seed planting materials. Further studies on mutation using tea planting materials would give an insight into its mutable gene behavior.
Subject(s)
Camellia sinensis , Gamma Rays , Seedlings/radiation effects , Mutation , Plant Leaves , TeaABSTRACT
Tea (Camellia sinensis L.) is the most popular beverage in the world after water. Due to acidophilic nature of tea plant, it has inherent tendency to uptake metals/metalloids including the toxic ones from the soil which is of great concern worldwide. In this study, level of chromium (Cr) and arsenic (As) were assessed in four hundred ninety-seven (497) black tea samples collected from six tea growing regions of Assam and North Bengal, India. The average concentration of Cr and As in the tested black tea samples was 10.33 and 0.11 µg g-1, respectively. Since tea is consumed as a beverage, transfer of Cr and As from black tea to its hot water extract (also known as tea infusion) was also accessed. The amount of Cr and As determined in the tea infusion was much less (< 0.20 to 1.38 µg g-1 for Cr and < 3.60 to 34.79 µg kg-1 for As) than those in the black teas with the transfer rate up to 5.96% and 8.53%, respectively. The present study showed that values of hazard quotient were well below one suggesting that intake of Cr and As from consumption of five cups of tea equivalent to 10 g black tea would not impose any health hazard.
