Growth Pattern of Tall and Short Lines of Rice and their Response to Gibberellin

The growth pattern of two types of dwarfness in rice was studied.The difference in height of the tall and short Peta plants wasapparent even at the seedling stage. In the dwarf and in thenormal Century Patna 231 the difference in height was apparentonly after panicle initiation. The four lines had the same numberof elongated internodes, with the taller lines having longerinternodes. The application of gibberellin resulted in increased plant height,longer internodes, blades and leaf sheaths, and decreased tillernumber. Century Patna 231-dwarf showed the least, and shortPeta the greatest, response to gibberellin application.