Karakter Root Re-Growth Sebagai Parameter Toleransi Aluminium pada Tanaman Padi

Abstract

Aluminum (AI) is one of the major limited factors in crop production on acid soils. Aluminum tolerant plants can be selected from plant breeding program by one of the physiological parameters representing AI tolerance character, such as root re-growth capability during recovery from the AI-stress. In this study we determined the concentration and time exposure of AI stress that was able to differentiate the response of three local upland rice varieties (Grogol, Hawarabunar and Krowal) and an AI-sensitive rice variety (IR64) to AI-stress, and evaluated the effectiveness of root re-growth (RRG) characters as an AI tolerance parameter in rice. The study consisted ofthree experiments, which were 1) nutrient culture experiment with different AI concentration treatments in growth chamber, 2) pot experiment in greenhouse using Jasinga yellow red podzolic acid soil containing 26,66 me/100 g AI and pH 4,6 as planting media, and 3) phenotyping of F2 population using RRG character. The results showed that AI treatment at 15 ppm for 72 h was able to distinctly differentiate between AI-tolerant (Grogol and Hawarabunar) and AI-sensitive varieties (Krowal and IR64). Planting ofthe rice varieties on acid soils showed similar result as that of the nutrient culture. Phenotyping of F2 population using RRG character indicated the existence of RRG value variation. These variations demonstrated that RRG character can be used as an AI tolerance parameter in rice and therefore can be effectively applied to screen rice F2 population that segregate to AI tolerance character.