Electronic Journal of Plant Breeding (Jul 2010)
Effect of physical mutagen on expression of characters in arid legume pulse cowpea (Vigna unguiculata (L.) Walp.)
Abstract
Studies on physical induced mutagenesis, gamma rays were performed by exposing the healthy and dry seeds of cowpeavariety CO 4 to gamma rays 20, 30, 40, 50, 60 and 70 kR. The study was to evolve economically important mutants withvaried seed coat colour as against dark grey coloured seed coat of CO 4. The LD50 value was found at 50kR for 60 Cogamma rays. Under field conditions, germination, seedling survival, plant height on 30th day, pollen fertility, seed fertility,pods per plant, pod length, seeds per pod, 100 seed weight and single plant yield was reduced as compared to the control. InM2 generation, viable macro mutants like dwarf mutant, spreading type, late mutant, semi sterile type, single and tricotyledonary leaf mutant, basal branching, multiple leaf mutant, white flower mutant, chimeric mutant and seed coat colourmutant were observed. Gamma rays induced higher proportion of chlorophyll mutations. Single type and multiple typemutations occurred more frequently. Economically important macro mutants such as brownish white seed coat colourmutants were observed in M2 generation.