Induction of genetic variability for quantitative traits in horsegram (Macrotyloma uniflorum) through irradiation mutagenesis

Abstract

Aim: The study was conducted to explore the magnitude of variability induced by gamma rays, electron beam and its combinations for quantitative traits in horsegram (Macrotyloma uniflorum (Lam) Verdc.). Methodology: The horsegram cultivar PAIYUR 2 was irradiated with twelve combinations involving G, EB and G+EB. Desirable mutagenic doses were identified in M1 based on plant injuries and forwarded to M2. Data on 11 yield component traits were recorded on normal looking M2 plants for identification of micro-mutants. Promising mutants were forwarded to M3 and the induced variability was ascertained using multivariate statistics. Results: Significant transgressive variants were observed in M2. The G+EB combination induced superior variants for yield. A positive shift in mean for yield and its attributing traits was observed in M3. Most of the polygenic traits were governed by additive gene effects. Interpretation: The increased mean for most of the polygenic traits in M3 population proved that selection made on early generation was highly effective. The isolated high yielding mutant progenies of selected families will contribute towards yield improvement in horsegram.