No abstract

No abstract

No abstract

This study was carried out with black gram (urdbean) variety TNAUCo(Bg)6 to determine the effects of gamma rays (150, 200, 250, 300 and 350 Gy) and ethyl methane sulphonate (10, 15, 20, 25, 30 mM). Data collected were on seed germination and survival, pollen and seed fertility, plant height, number of primary branches, number of clusters per plant, number of pods per plant, pod length, number of seeds per plant, hundred seed weight and yield per plant in M 1 generation. Thereafter, progressive reduction in germination and survival percentage, pollen and seed fertility and yield related traits were observed in the mutagenic treatments. Deleterious effects were more pronounced in higher doses, indicating almost a linear relationship. LD 50 values of 41.30 and 43.50% were observed in 20 mM of ethyl methane sulphonate and 250 Gy of gamma rays, respectively. The increasing doses of gamma rays and ethyl methane sulphonate decreased in phenotypic and yield related parameters. The reduction in quantity and yield traits has been attributed to the physiological disturbance or chromosomal damage of the cells of the plant caused by the mutagens. Ethyl methane sulphonate was observed to be more effective than gamma rays as it generated more number of mutants, which later caused higher physical injury.

Tropical Indian maize inbreds are known for their recalcitrance in tissue culture which is a prerequisite for development of transgenic lines from such cultivars. In the present study, particle bombardment-mediated transformation of a tropical Indian maize inbred line, UMI29 was attempted. Parameters that infulence transforamation efficiency such as size of embryo (1.5 mm and 2.0 mm), micro-carrier flying distance (6 cm and 9 cm) and post-bombardment resting period (2, 7 and 10 days) on transient and stable expression of transgene were investigated. The greatest transformation efficiency of 2.67% was obtained using immature embryos of 1.5 mm at 6 cm of microcarrier flying distance with a resting period of 2 days. Stable inheritance of transgenes, viz., gusA and bar was confirmed in T1 lines.