Thumbnail Image

Theses

Browse

2017 - 201912020 - 20222
 Reset filters

Settings

Author: Sharma, Richa ×

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    ThesisItemOpen Access
    Association Analysis of White Rust Resistance Genes and Studies on Transformation Response of Susceptible Genotypes of Brassica juncea L.
    (Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu, 2022-10) Sharma, Richa; Sharma, Manmohan
    The study entitled “Association Analysis of White Rust Resistance Genes and Studies on Transformation Response of Susceptible Genotypes of Brassica juncea L.” was conducted to analyse the population structure of B. juncea genotypes for white rust resistance and economically important traits; to detect single nucleotide polymorphisms (SNPs) and establish marker-trait association in Brassica juncea for white rust resistance and economically important traits; and to screen the variants for response to Agrobacterium tumifaciens mediated transformation in elite white rust susceptible B. juncea varieties. To accomplish the study a diverse panel of ninety Brassica juncea genotypes was used. Data of the experimental genotypes were recorded for traits such as white rust reaction, grain yield/plant, oil content, erucic acid and glucosinolate content using standard protocols. The germplasm was genotyped by genotype-by-sequencing (GBS) with ddRAD strategy using restriction enzymes Sph1 and Mluc1.Population structure analysis was done using fastSTRUCTURE software. The genome wide associations between SNP identified and trait studied were done using TASSEL (5.2.81) software involving Mixed Linear Model. Agrobacterium mediated genetic transformation was done using hypocotyl and cotyledonary leaf explants from two varieties of Brassica juncea (RSPR 01 and Varuna) by optimizing various factors influencing transformation. Agrobacterium strain LBA4404 containing plasmid pBI121 and reporter gene GUS was used in the study. Genotypes Donskaja IV, Domo and Cutlass showed immune reaction against white rust and could be used as resistant sources for breeding white rust resistant varieties. Genotypes DRMR-2017, J807/1/6 and Vardan for higher grain yield per plant; PGR 12573, EC 287711, Stoke and Jubilejnaja for oil content; Donskaja IV, Volgogradskaja 1891 and PGR 12573 for low erucic acid and Heera for low glucosinolate contents were identified which will be useful for improvement of these traits in new Brassica juncea varieties being developed. Population structure analysis based on trait and SNP data indicated significant variation in the germplasm with broader distribution into Indian and East European gene pools. Most significant SNPs associated with each trait were identified which could be further validated for utilization in marker assisted selection of these traits and their introgression into other genetic backgrounds. Agrobacterium suspension with an optical density of 0.6 at 600 nm, co-cultivation period of 48 hours and kanamycin concentration of 25 mg/l were found as the most optimum conditions for affecting maximum transformation in Brassica juncea varieties RSPR 01 and Varuna. Hypocotyls were found better than cotyledonary explants and variety RSPR 01 better than variety Varuna for higher transformation response.
  • Thumbnail Image
    ThesisItemOpen Access
    Propagation studies of Kagzi lime (Citrus aurantifolia Swingle) under Jammu region
    (Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu, 2022-01) Sharma, Richa; Kumar, Rakesh
    The present investigation was undertaken to study the “Propagation studies of Kagzi lime (Citrus aurantifolia Swingle) under Jammu region” at the Rainfed Research Sub-Station for Sub- Tropical Fruits (RRSS), Raya (SKUAST- Jammu) during the rainy season of 2020- 2021. The experiment was laid out in factorial RCBD with three replications and sixteen treatments. There were three levels of IBA (500 ppm, 1000 ppm and 1500 ppm) along with control (water) and four rooting media in different ratio, soil + sphagnum moss (2:1); soil + cocopeat + vermicompost (2:1:1) and soil + F.Y.M + sand (2:1:1) along with the control (soil). IBA@ 1500 ppm was found effective in maximizing success percentage (%) of layered plants (87.66%); root parameters i.e. number of primary roots (24.31), maximum length of primary roots (6.58 cm), number of secondary roots (30.28), maximum length of secondary roots (7.84 cm); survival percentage of air layered plants (88.08%); growth parameters including shoot parameters i.e. number of shoots (7.70) and number of leaves per shoot (24.02); leaf parameters viz., number of leaves per plant (48.42), leaf area (50.47 cm2), fresh weight of leaves (54.24 g), dry weight of leaves (6.69 g), leaf chlorophyll content (47.86) and leaf area index (0.54) whereas, least values for same were reported in control. Rooting media, soil and sphagnum moss (2:1) was also found effective in maximizing all above given parameters as compared to soil. Interaction effect of growth regulator and rooting media, IBA@1500 ppm + soil and sphagnum moss (2:1) proved significant in maximizing success percentage (%) of layered plants (95.99%); root parameters; survival percentage of air layered plants (98.68%); growth parameters including shoot parameters; leaf parameters whereas, minimum success percentage (%) of layered plants (62.69%) was reported in control. Also, maximum B:C ratio of 1:4.8 was recorded in above cited treatment and minimum of 1:0.2 was recorded in control. Hence, it can be ascertained that for layering in Kagzi lime, best results can be obtained with the combined effect of IBA@1500 ppm as rooting treatment and soil + sphagnum moss (2:1), as rooting media.
  • Thumbnail Image
    ThesisItemOpen Access
    CHARACTCRIZATION OF PEA GERM PLASM USING EST -SSR MARKERS AND BIOCLTEMICAL TRAITS
    (Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu, 2017) Sharma, Richa; Sharma, Susheel
    Information about genetic diversity of any crop is Important for successful employment of breeding programmes. EST-SSRs, because of their intrinsic advatages can serve as potential tool for inferring diversity among Pisum accessions. In the present study, an initiative was taken to characterize genetic diversity among 40 different Pisum genotypes, collected from various sources/locations, using EST-SSrs and biochemical traits. For molecular characterization, thirty five EST-SSRs chosen from previous studies were used, of which only 24 could be optimized for further usage. PIC value for these markers ranged from 0.500 (Pea-069) to 0.095 (Pea-097) with an average of 0.349. Similarly, other informative parameters viz., marker index (M1) and resolving power (Rp) were also worked out. Genetic similarrity estimates based on the binomial data using Jaccard's coefficient ranged from 0.17 (Azad Pea 1/IC-219010) to 0.92 (IC-219010/219008) with an average value of 0.45 exhibiting considerable diversity among the pea genotypes studied suggesting the further use of these diverse parents in hybridization for generating transgressive segregates. The similarity estimates then used to execute clusters A and B which were further divided into sub clusters. For biochemical analysis data on three important traits viz., protein content (%), total sugar content (%) and ascorbic acid content (mg/100g) were recorded. The mean data of various genotypes for protein content (%), total sugar content (%) and ascorbic acid content (mg/100g) ranged from 25.09(IC-208366) to 16.07 (Azad P3), 19.97 (Lincoln) to 12.65 (IC-218991) and 5.57 (DPPIV-2) to 3.01 (Arka Pramodh), respectively. Identified promising lines for various biochemical traits can in future be employed to improve the target traits. Thus, information obtained from EST-SSR markers and biochemical parameters may well assist pea breeders in executing breeding programmes. Informative SSR markers exhibiting high PIC, Rp and MI can supplement in assessing genetic variability and MAS programmes. The highly divergent lines so observed can further be used in pea pre-breeding programmes to broaden the narrow genetic base of existing varieties as an assurance against unforeseen biotic and abiotic stresses.