Induced lodging resistance in littlemillet (Panicum sumatrense) through gamma irradiation

Enlarging the variability and widening the selection for non-lodging and high yielding varieties in littlemillet, induced mutagenesis has been resorted. Recently released littlemillet varieties CO3 and CO(Samai)4 were selected as the parent genotype and they were exposed to 300, 400, 500, 600 and 700 Gy of gamma rays. The treated seeds were sown in the field along with control to raise M1 and they were forwarded to M2 and M3 generation. Lodging susceptibility score were recorded in M2 and M3 generation. With reference to lodging susceptibility, the maximum heritability and genetic advance was recorded in the progeny of 600Gy in M2 generation of CO(Samai)4 and 300Gy in M3 generation of CO3. The lodging resistance is closely associated with shorter plant height, thick culm and reduced internodal length. Accordingly, selection based on these characters along with lodging resistance in mutagenic dose at 600Gy was found to be effective in CO(Samai)4 variety in M2 population. Similarly mutagenic dose at 300Gy was found to be effective in M3 generation of CO3. In M2 generation of CO3 lodging resistance recorded positive Skewness value (0.26) and the complementary epistasis gene action was confirmed. Where as in M2 generation of CO(Samai)4 lodging resistance recorded inconsistent negative value (-0.07) for Skewness and indicated that genetic equilibrium of these character was disturbed by the irradiation. The inconsistent trend in frequency distribution suggests that besides selection, other genetic factors might have influenced the induction and expression of micro mutations. Hence, to select lodging resistant genotypes, we have to screen more number of mutated populations to have better combination of lodging resistant alleles. (author)