COMPARISON OF TOLERANCE LEVEL OF ORYZA SATIVA VAR. SARINAH AND VAR. ROJOLELE UNDER CR (VI) HEAVY METALS STRESS

• Main Author: Purnamawati, Rizka
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/52276
• Institution: Institut Teknologi Bandung

Sarinah rice variety (Svar) and Rojolele (Rvar) are two varieties of rice that are widely planted by farmer in Garut and irrigated by contaminated waste water from leather and tanning industry. Tanning waste contains chromium metal which is considered to have a negative impact on rice crops. In this study, paddy plants (Svar and Rvar) was treated by polluted river water (PRW), K2Cr2O7 solution with concentrations of 50 ppm and 100 ppm with gradual additions and water (negative control) until the plant can be harvested. The observation of rice including growth and grains production parameters, measurement of physiological parameters and activity of antioxidant enzymes using spectrophotometers. Statistical analysis was carried out by One-way ANOVA using IBM SPSS software version 25. The results showed changes in rice growth, plants height, root length and rice weight. The highest accumulation of Cr was in roots part from both varieties 29.49 mg/kg (Svar) and 15.83 mg/kg (Rvar). The decrease of plants height reached 24.67% compared to negative control, the decrease in root length up to 26.03%, fresh weight loss up to 26.52% and dry weight loss up to 36.69% in Svar. In Rvar, the percentage of decrease in shoot height up to 9.86%, root length up to 38.71%, fresh weight 32.14% and dry weight up to 19.72% for Cr 100 ppm treatment compared to negative control. In addition to affecting growth, Cr also affected grains production during harvest, Cr was accumulated in paddy grains 17.62 mg/kg (svar) and 3.62 mg/kg (Rvar), there was a decrease in total grain and increased in empty grain up to 50.21% for Svar and Rvar up to 31.95% for Cr 100 ppm treatment. Chlorophyll content decreased along with the increasing concentration of Cr in the media. Total chlorophyll decreased up to 55.73%, chlorophyll A 55.74% and chlorophyll B 55.71% for Svar. Total chlorophyll in Rvar also decreased up to 36.55%, chlorophyll A up to 38.09% and chlorophyll B up to 33.94% for Cr 100 ppm treatment. Proline levels increased along with the increase of Cr concentration in the media. In Svar, there was an increase in proline levels compared to negative control up to 50.75% in the root and 53.14% in the shoot and Rvar increased up to 77.29% in the root and 76.03% in the shoot for Cr 100 ppm treatment. CAT and APX enzyme activity increased compared to negative control up to 76.35% and 80.95% in Svar, meanwhile in Rvar CAT and APX enzyme activity increased up to 68.02% and 52.51% for Cr 100 ppm treatments. Both varieties of rice changed in growth response, physiological and antioxidant enzyme activity due to the accumulation of heavy metals Cr at the roots, stems and grains. Rvar has better tolerance level than Svar due to the difference in Cr absorption, growth decreasing, lower filled grain production, increasing proline and the activity of antioxidant enzyme compared to Svar when there was Cr accumulation in plants organ.