Abstract
The agronomic performance of 18 M4 generation mutants of aromatic rice (Oryza sativa L.) was evaluated along with their two mother genotypes, IET 14142 and IET 14143. IET 1412 and IET14143 were developed from Tulaipanja, an aromatic non-basmati rice cultivar, popularly grown in northern parts of West Bengal - an important rice growing province of India. The results indicate that there is a considerable amount of genetic variability among mutants with respect to thirteen quantitative characters. Some of the mutants had a combination of both positive and negative forms of important yield contributing characters. The performance of four mutants (T1m1, T1m6, T2m4 and T2m8) indicated considerable improvement in grain yield over their respective control. The increased grain yield per plant in the above high yielding mutants is primarily due to increase in panicle number per plant, spikelet number per panicle, grain number per panicle and test weight. These mutants need further evaluation in multilocation trials to judge their potential as varieties of aromatic rice. The other mutants may be used in cross-breeding programmes of aromatic rice for agronomically useful characters i.e., early flowering, short stature, erect flag leaf, high grain number, heavy weight per 100 grains. The apparent changes in different characters in an individual mutant may not be due to genetic changes in all the affected characters. The possible role of pleiotropic effects of mutant genes cannot be ruled out.
