The Effects of Gallium and Indium on the Growth of Rice Seedling (Oryza sativa L.) in Solution Cultures

• Main Authors: Po-Hsuan Chien, 簡柏勛
• Other Authors: 李達源
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/95933393492344678653

碩士 === 國立臺灣大學 === 農業化學研究所 === 103 === Gallium (Ga) and indium (In) compounds are commonly used in semiconductor manufacturing industry and electro-optical industry. Human beings may also expose to Ga and In via food-chain, which could lead to increase of health risks. To our best knowledge, there are few studies to investigate the effects of Ga and In on the growth of crops. Thus hydroponic experiments were conducted to evaluate the effects of Ga and In on the growth and uptake of these two elements of rice seedlings. Rice (Oryza sativa L.) seedlings were cultivated in modified half-strength Kimura B nutrient solutions for two weeks, after that rice seedlings were exposed to modified full-strength Kimura B nutrient solutions containing various Ga and In concentrations. The treatments included: Gallium (control, 1, 3, 5, 10, 15 mg L-1), Low-In concentration (L-In) (control, 0.04, 0.08, 0.1, 0.15, 1, 2 mg L-1) and High-In concentration (H-In) (control, 0.1, 1, 3, 5, 10 mg L-1) treatments. Ga and L-In treatments were grown in Nov. and Dec. for 40 days; H-In treatment was grown in July and Aug. for 25 days. All hydroponic cultures were performed in the Phytotron of National Taiwan University at day 25°C / night 20°C, relative moisture 70-95% and natural light. The results revealed that rice seedlings could absorb Ga and In, and transfer these two elements from root to shoot in the plant, but most of them were accumulated in root. Gallium stimulated growth of rice seedlings when concentration was below 10 mg Ga L-1, however, growth of rice seedlings was inhibited by In as concentration reached 0.08 mg L-1. SPAD value increased in Ga treatment, nevertheless, chlorosis would occur when concentration of In was 1 mg L-1 in H-In treatment. Our results suggested that Ga might promote N and K uptake, but decrease the uptake of Fe, Mn and P by rice seedlings. The absorption of Ca, Mg and Fe in rice seedlings was inhibited in L-In treatment. The uptake of Ca, Mg, Fe, Mn and Zn by rice seedlings was inhibited in H-In treatment.