PHOSPHORUS UTILIZATION AND CHARACTERISTICS OF ROOT AND TOP OF RICE PLANT

The improvement of rice plants (Oryza sativa L.) for better P use efficiency is important to decrease the cost of rice production and maximizing yields. The objective of the present study was to understand the relationship among root and shoot characteristics with P use efficiency and other characteristics of the rice plant. Twenty-five genotypes of rice were grown in soil and in vitro under two level of P: low (0 mg of P dm(-3)) and high (150 mg of P dm(-3)) in soil, and 0 and 17 mg of P dm(-3) in vitro. In soil at low level of P, the plant height and number of root per plant had the highest direct effect on P use efficiency. At high P level, the number of leaves per plant and root length had the highest direct effect on P use efficiency. In vitro, under all conditions of evaluation and levels of P, the level of P accumulation in the plant and root volume had the highest direct effect on P use efficiency.