Paramjit SinghGurcharn Singh2023-06-292023-06-292022Gurcharn Singh (2022).Characterization of introgressed Gossypium hirsutum lines for cotton leaf curl disease resistance (Unpublished M.Sc. thesis). Punjab Agricultural University, Ludhiana, Punjab, India.https://krishikosh.egranth.ac.in/handle/1/5810197840The plant material consisted of BC2F4 progenies obtained from G. hirsutum cv. F 1861/G. armourianum acc. PAU 1/G. hirsutum cv. LH 1556 cross. This material was evaluated for CLCuD response and several other economic traits. For inheritance of CLCuD resistance and identification of SSR markers linked to CLCuD resistance, a BC5F2 population derived from the cross: G. hirsutum cv. F1861/ G. armourianum acc. PAU 1/*5G. hirsutum cv. F 1861 was used. A set of 121 backcross progenies including F 1861, LH 1556 and F 2228 were planted during kharif 2020 in a simple lattice design (11 x 11) with two replications. A set of 85 cotton specific SSR markers were used for documenting polymorphism between the parents and genotyping the mapping population. Six progenies were observed to be completely free from the disease, 76 progenies were segregating for CLCuD reaction, whereas, 36 backcross progenies were found to be completely susceptible to CLCuD. A simple genetic control for CLCuD resistance (monogenic dominant) has been observed in this material. Significant differences among the cotton genotypes were observed for seed cotton yield, upper half mean length, uniformity index, tenacity and micronaire indicating substantial variation for these characters in the experimental plant material. Mean seed cotton yield plant-1 ranged from 46 g (Progeny 53) through 129.5 g (progeny 298). None of the 118 backcross progenies could significantly out yield standard check F 2228 (126 g), though one progeny 298 produced numerically higher (129.5 g) seed cotton yield than that of the check. Mean fibre strength ranged from 24.9 g/tex (Progeny 567) through 32 g/tex (progeny 113). Sixty four progenies significantly outperformed the check F 2228 (26.65 g/tex). Mean micronaire value ranged from 3.85 (Progeny 108) through 5.4 (progeny 412). Most of the backcross progenies significantly outperformed the standard check F 2228 (5.3) for this trait. One SSR marker (NAU 3903) was found to be polymorphic between the resistant and susceptible F2 bulks.EnglishThesis