Genetic Enhancement of Variability Through Induced Mutagenesis in Two Genotypes of Brassica napus L.

Abstract

The present study deals with the extent of variability for yield, yield components and oil content in the 24 gamma-ray induced mutants (M7 generation) of two genotypes of Brassica napus L. A highly desirable shift in mean values in the mutants as compared to national check, GSL-1 was observed for almost all the characters. The highest range of variation was recorded in grain yield (3.58-9.46 g) followed by number of primary branches (5.2-12.3), 1000- grain weight (1.76-3.93 g) and no. of siliquae per plant (113.10- 236.1). The maximum value of PCV was obtained for number of grains per siliqua followed by grain yield per plant and 1000- grain weight. The characters, such as, days to 50 per cent flowering, days to maturity, length of siliqua, plant height, number of primary branches, grain yield per plant and 1000- grain weight showed high heritability (more than 80%). Among component traits, plant height, length of siliqua, no. of grains per siliqua, no. of siliquae per plant and 1000 – grain weight showed strong positive correlation with seed yield per plant. Mutants, such as, GSM-1, GSM-2 and GSM-14 showed enhanced level of oil content, test weight and grain yield. The isolation of certain promising mutants signified the role of mutation breeding in enhancing the genetic variability in Brassica napus L