Advisor : RATHOD, Dr. D. R.Authors : BHOJANE, PALLAVI NARENDRARAO.2022-02-152022-02-152022-01-27Citation : BHOJANE, PALLAVI NARENDRARAO. (2020). Molecular assessment of single cross hybrids of desi cotton for yield and boll related traits using SSR markers. Biotechnology Centre, Department of Agricultural Botany. Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola. M. Sc. 2020. Print. xiv, 83p. (Unpublished).https://krishikosh.egranth.ac.in/handle/1/5810182347Description : This experiment was conducted during the year 2019-20 at Department of Biotechnology Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, Dist. Akola (Maharashtra). In this experiment the investigation was carried out to evaluate single cross hybrids of desi cotton for yield and boll related traits and to confirm hybridity of single cross and double cross hybrids using SSR markers.Abstract : Present experiment entitled “Molecular assessment of single cross hybrids of desi cotton for yield and boll related traits using SSR markers” was undertaken at Biotechnology Centre, Dept of Agril. Botany, Dr. PDKV, Akola during 2019-20 with objective to transfer important traits related to boll size and seed cotton yield to enrich gene pool of G. arboreum (desi) cotton using popular and released varieties viz., AKA-7 (P1), Phule Dhanwantari (P2) as a female parent, while donor parent’s G. cernuum (D1) and PA-812 (D2). Four single cross hybrids viz., SC-I (AKA-7xG.cernuum), SC-II (AKA-7xPA-812), SC-III (PD x G.cernuum) and SC-IV (PDxPA-812) attempted during 2018-19 were used further to develop possible two double cross (DC) and one multi cross (MC) hybrids. Accordingly, a total of 333 crosses were attempted consisting of 59, 102, 67 and 105 crosses of SC-I, II, III and IV respectively. Out of these, a total of 55 crosses made successful with 10, 18, 7 and 20, from crosses of SC-I, II, III and IV respectively. A total of 971 F1s seeds harvested individually with 190, 377, 131 and 273 seeds from single crosses SC-I, II, III and IV, respectively. From these single crosses, a total of 118 double cross seeds consisting of DC-I 52 seeds and DC-II 66 seeds were obtained. Harvested seeds from each individual crossed boll of four SC and two DC hybrids were raised for its phenotypic and genotypic evaluation during off-season nursery under polyhouse facilities. Simultaneously, raised seedlings were subjected for molecular assay to ensure its successful crossing. Mean performance of varietal features of parents were assessed under field condition for nine quantitative characters viz., days to 1st flower, days to 1st boll bursting, plant height, no. of monopodia, sympodia and bolls plant-1, boll weight and size, seed cotton yield plant-1. Morphological data recorded on five randomly selected plants confirms its varietal identity. Few SC and DC progeny lines found promising for boll wt. 3.70 -5.10g big boll size. During molecular characterization, parental polymorphism survey was undertaken using 70 microsatellite markers. Out of these 31 SSRs were not amplified and uninformative, whereas remaining 39 shows satisfactory level of amplifications. Among these 39 SSR amplified in parental population, only 20 SSR shows polymorphism among parents and their resultant SC hybrids. Remaining 11 SSR shows monomorphic bands, hence discarded. Among polymorphic 20 SSRs, only 8 SSR were able to distinguish SC and DC hybrids and only these markers used to characterize SC and DC hybrid progeny population. Remaining 12 SSR among 20 polymorphic observed, where found non consistent in hybrids, when tested in either SC or DC. The average number of alleles was found 3.44 primer-1 with highest polymorphism (94%). Among SSRs, only BNL-1694 and BNL-3580 showed highest level of polymorphism 94%. A total eight DC hybrids, out of 118 obtained in DC-I and DC-II were confirmed as true hybrids by SSR genotyping. These true hybrids were further evaluated for trait evaluation and introgression of gene in segregating progenies of each single cross and double cross hybrids.EnglishThesis