BS DiltaPARINITI KUMARI2024-04-252024-04-252024-02-24https://krishikosh.egranth.ac.in/handle/1/5810208395The investigation titled, "Effect of EMS and colchicine treated seeds on plant growth and flowering in marigold" was carried out at the Research Farm and Laboratory of the Department of Seed Science and Technology, Dr YS Parmar University of Horticulture and Forestry, Nauni, Solan (HP) during the years, 2021-22 and 2022-23. The seeds of two cultivars namely, ‘Pusa Bahar’ and ‘Pusa Deep’ of marigold were treated with 14 treatments viz., T1 (control), T2 (hydropriming for 12 hours), T3 (hydropriming for 12 hours + seed soaking in 0.25% EMS for 6 hours), T4 (hydropriming for 12 hours + seed soaking in 0.50 % EMS for 6 hours), T5 (hydropriming for 12 hours + seed soaking in 0.75 % EMS for 6 hours), T6 (hydropriming for 12 hours + seed soaking in 1.00 % EMS for 6 hours), T7 (hydropriming for 12 hours + seed soaking in 1.25 % EMS for 6 hours), T8 (hydropriming for 12 hours + seed soaking in 1.50 % EMS for 6 hours), T9 (hydropriming for 12 hours + seed soaking in 0.025% colchicine for 1.5 hours), T10 (hydropriming for 12 hours + seed soaking in 0.050 % colchicine for 1.5 hours), T11 (hydropriming for 12 hours + seed soaking in 0.075 % colchicine for 1.5 hours), T12 (hydropriming for 12 hours + seed soaking in 0.100% colchicine for 1.5 hours), T13 (hydropriming for 12 hours + seed soaking in 0.125 % colchicine for 1.5 hours) and T14 (hydropriming for 12 hours + seed soaking in 0.150 % colchicine for 1.5 hours). The experiment was laid out in RCBD (factorial) for field studies. Data on various growth and flowering parameters were recorded. The germination percentage, plant height, duration of flowering and peduncle length decreased with the increase in the EMS and colchicine concentrations. Among the EMS treatments, maximum value for plant spread (54.03 cm and 55.21 cm), number of branches (26.01 and 17.76) and number of flower heads per plant (48.85 and 62.40) in both the cultivars (‘Pusa Bahar’ and ‘Pusa Deep’) were recorded in T7. In ‘Pusa Bahar’ and ‘Pusa Deep’, the maximum flower head diameter (4.68 cm and 3.68 cm) and flower head weight (4.66 g and 1.76 g) was recorded in T3. Among the colchicine concentrations, the highest number of branches (29.45 and 18.97), number of flowers per plant (40.56 and 61.39), flower diameter (4.94 cm and 3.97 cm) and flower weight (4.94 g and 1.94 g) was recorded in T12 in both the cultivars. Variations in foliage colours and flower head colour were also observed in T4, T5, T6 T7, T9, T10, T11, T12, T13 and T14. One sectorial chimera was also induced in one flower head in ‘Pusa Deep’ by treatment T14. Accordingly, it is concluded from the outcomes of the investigation that seed treatment with T7 and T12 can be recommended to promote the growth and flowering characters in marigold cultivars, ‘Pusa Bahar’ and ‘Pusa Deep’. In addition, 20 variants (10 each in ‘Pusa Bahar’ and ‘Pusa Deep’) were induced with various treatments and which were identified, selected and evaluated under this investigationEnglishThesis