PHYTOTOXICITY OF CHROMIUM (VI) ON PADDY (ORYZA SATIVA L.) VAR. CIHERANG AND VAR. SARINAH

• Main Author: Roro Deby Anindya, Raden
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/50387
• Institution: Institut Teknologi Bandung

The leather tanning industry in the Sukaregang area, Garut uses chromium in the leather tanning process to produce liquid waste containing Cr. Untreated liquid waste can pollute rivers around the industry, then the polluted river water has been using by farmers to irrigate their fields. This research was conducted to evaluate the phytotoxicity of heavy metal (Cr) on paddy. Germination test used UKDdp method (Rolled Paper Test in an Established Position), two rice varieties were used, var. Ciherang and var. Sarinah were each treated with river water contaminated with liquid waste (positive control), K2Cr2O7 solution with concentration of 50, 100, and 200 mg/L, and distilled water (negative control) with six replications, for seven days. The research was continued by testing the toxicity of paddy var. Ciherang treated with Jatinangor soil (negative control), Sukaregang Garut rice field soil (positive control), and K2Cr2O7 solution with concentrations of 50, 100, and 200 mg/L that replicates seven times. Paddy treated with 100 and 200 mg/L Cr died on the first week, so that no further observations could be made. The result is Cr 50-100 mg/L treatment decreased the germination percentage by 6-7% and the Cr 200 mg/L treatment decreased by 16%. On phytotoxicity test, the 50 mg/L Cr treatment inhibited shoot growth by up to 12.78%, reduced grain production by 46.37%, and caused an increase in the number of empty grains up to 29.16%. Treatment of positive control inhibited the growth of paddy roots by up to 48.69%. The Cr concentration that accumulated in the roots was 232.93 mg/kg, on stems 8.44 mg/kg, on leaves 12.73 mg/kg, and on grains 6.38 mg/kg. According to PP RI No. 82 of 2001, the quality standard for Cr content in irrigation water was 0.01 mg/L, while in this study the Cr content in river water reached 2.301 mg/L. In Cr 50 mg/L treatment, chlorophyll content in paddy decreased to 60.82%, while the proline concentration in leaves increased by 18.47%. The activity of CAT and APX enzymes also increased, especially in paddy leaves after receiving Cr 50 mg/L treatment, with the highest CAT activity value reaching 1990.31 units/mg (an increase of 76.76%) and APX activity of 59.91 units/mg (an increase of 81.02%). Cr treatment at concentrations above 50 mg/L inhibited the growth of roots and shoots of paddy. Cr metal is absorbed by plants and translocated to rice grains so that it can be dangerous if consumed by humans. The physiological condition of paddy is disturbed due to the accumulation of Cr in plant tissue, this is indicated by a decrease in chlorophyll contents, an increase in proline concentrations, as well as an increase in CAT enzyme activity and APX enzyme activity.