BREEDING FOR HIGH GRAIN YIELD THROUGH MUTAGENESIS IN RICE (ORYZA SATIVA L.)

Abstract

A high yielding mutant IR6-25A was selected from gamma rays irradiated material of
coarse (non-aromatic) rice variety IR6 and was evaluated at the experimental farm of
Nuclear Institute of Agriculture (NIA) Tando Jam. The mutant strain IR6-25A was
significantly (P  0.05) better than its mother variety IR6 and check variety Shadab in the
entire yield contributing parameters. It gave better paddy yield as compared to its parent,
check other promising mutant strains in Micro, Preliminary and Station Varietal Trials at
NIA, Tando Jam during 1996, 1997 and 1998. On the basis of three years average, it has
shown 16% increase in paddy yield over its parent-IR6 as well as check variety Shadab. In
Zonal Varietal Trials, conducted for three subsequent years at 9 different locations with
diverse agro-climate conditions, it maintained superiority over all the entries by yielding
6816, 6208 and 6530 kg of paddy per hectare during 1999, 2000 and 2001 respectively. It
gave 20% and 23% higher paddy yield than IR6 and check variety Shadab