Induced mutagenesis in creating genetic variability for seed yield and Alternaria leaf blight resistance in sunflower (Helianthus annus)

摘要

The successful use of plant breeding for improving desirable traits requires the existence of genetic variability for these traits. Induced mutations are often used to create new genetic variability within a plant species. The objective of this study wasto provide new genetic variability that can be exploited for improvement of important agronomic and Alternaria leaf blight resistance traits in sunflower production. The seeds of TX16-R sunflower lines from the Directorate of Oilseed Research, Hyderabadwas irradiated with gamma rays (y) and treated in an ethyl-methane sulphonate (ems) solution. The manifestation of mutations was mostly expressed in the Mj mutants were selected. Induced mutagenesis of TX-16R with gamma rays at two doses (200 Gy and 250Gy) and with chemical mutagen EMS with two concentrations (0.015 mols/dm~3 and 0.020 mols/dm~3) was attempted to improve TX-16R for resistance to Alternaria leaf blight and agronomical traits. Gamma rays treatment at 250 Gy resulted in higher mortalityand plants did not survive till the maturity. M, generation was raised along with control. In M~2 generation, more variability for resistance to blight and agronomic traits was seen in populations derived from EMS 0.020 mols/ dm~3 treatment compared to 200 Gy (gamma rays) and EMS treatment at 0.015 mols/dm~3 concentration and among three Mj population 200 Gy treatment has given higher frequency of highly resistant plants compare to 0.020 mols/dm3 and 0.015 mols/dm~3 EMS treatment indicating that 200 Gytreatment is more desirable for getting highly resistant plants for Alternaria disease reaction.