EFFECT OF ZINC ON GRAIN CHARACTERISTICS OF DRAFT-RESISTANT RICE MUTANTS

Through the use of Instrumental Neutron Activation Analysis (INAA), ti nt concentration was determined in kernels resulted on plants of six d rought-resistant rice mutant lines fertilized with zinc sulphate. It w as found that zinc fertilization increased zinc residues in the kernel s with varying concentrations depending on the line, each line reacted and responded to zinc independently. Zinc content in the kernels rang ed from 5.63 to 91.4 ppm in the unfertilized control lines. This range was enlarged due to zinc fertilization of the plants to be from 93.51 to 554.53 ppm. It was also noticed that zinc fertilization increased seed heaviness in varying degrees depending on the line itself. This i ncrease may be due to the increase in kernel thickness rather than in kernel width or length.