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ThesisItem Open Access Analysis of genetic diversity of Indian melon (Cucumis melo L.) land races and its comparison with global reference melon populations(PAU, 2012) Malik, Ajaz Ahmed; Vashisht, V. K.The present investigation entitled, “Analysis of genetic diversity of Indian melon (Cucumis melo L.) land races and its comparison with global reference melon populations” was conducted at Department of Vegetable Science and School of Agricultural Biotechnology, Punjab Agricultural university Ludhiana, during the years 2009 and 2010. Eighty-eight melon accessions collected from utrakhand and Uttar Pradesh states of India representing four agroecological regions (six sub-regions) and eight reference accessions from USA were characterized and evaluated for nineteen morphological traits of plant and fruit, biochemical traits such as T S S, ascorbic acid content, titrable acidity and dry matter content, SSR genotyping and reaction to diseases. Significant differences were noted among all the accessions for all the characters observed. Phenotypic and genotypic coefficients of variation were found to be high for fruit weight and node at which first hermaphrodite flower appears. High heritability alongwith high genetic advance was recorded for fruit weight, node at which first hermaphrodite flower appears, fruit length, seed cavity length, number of primary branches per vine and total soluble solids content. D 2 analysis grouped the accessions into ten clusters. The reference accessions obtained from USA and land races collected from different agro-ecological zones of India were found to be scattered in different clusters. No parallelism was found between genetic and geographic diversity. DNA polymorphism was utilized to cluster the genotypes into different clusters based on similarity as well as dissimilarity coefficients. On basis of SSR analysis, dendrogram clustered 96 accessions into three major groups. There was a significant correlation between botanical groups and the clustering pattern. Accessions elonging to cantalupensis cluster together in cluster I, accessions of reticulatus group cluster together in cluster II and momordica group cluster together in cluster III. However, some accessions of cantalupensis and reticulatus were intermixed in cluster I and II. Reference accessions cluster together forming a genetically unique assemblage in subgroup IIA and shared similarity coefficient of 0.65 with sub-group IIB. This suggested that reference accessions shared genetic affinities with Indian melon accessions that co uld not have been predicted based on their geographic origin. Four accessions were free from CMV and two accessions exhibited immune reaction to downy mildew. The results inferred that these melon accessions could be used to broaden the genetic base of melon.ThesisItem Open Access Characterization Of Melon Germplasm Using Sds-Page Of Seed Proteins(Punjab Agricultural University ;Ludhiana, 2003) Parmar, Ajigurt Manu; Tarsem LalThesisItem Restricted Studies On Genetic Variability For Some Physico-Morphological And Biochemical Traits In Tomato ( Lycopersicon Esculentum Mill.)(Punjab Agricultural University ;Ludhiana, 2003) Ravinder Kaur; Cheema ,D. S.ThesisItem Open Access Studies On Heterosis And Combining Ability Involving Ripening Mutants In Tomato (Lycopersicon Esculentum Mill.)(Punjab Agricultural University; Ludhiana, 2006) Garg, Naveen; Cheema, D.S.ThesisItem Open Access Analysis of genetic diversity of Indian melon (Cucumis melo L.) land races and its comparison with global reference melon populations(Punjab Agricultural University, Ludhiana, 2012) Ajaz Ahmed Malik; K VashishtThe present investigation entitled, “Analysis of genetic diversity of Indian melon (Cucumis melo L.) land races and its comparison with global reference melon populations” was conducted at Department of Vegetable Science and School of Agricultural Biotechnology, Punjab Agricultural University Ludhiana, during the years 2009 and 2010. Eighty-eight melon accessions collected from Uttrakhand and Uttar Pradesh states of India representing four agroecological regions (six sub-regions) and eight reference accessions from USA were characterized and evaluated for nineteen morphological traits of plant and fruit, biochemical traits such as T S S, ascorbic acid content, titrable acidity and dry matter content, SSR genotyping and reaction to diseases. Significant differences were noted among all the accessions for all the characters observed. Phenotypic and genotypic coefficients of variation were found to be high for fruit weight and node at which first hermaphrodite flower appears. High heritability alongwith high genetic advance was recorded for fruit weight, node at which first hermaphrodite flower appears, fruit length, seed cavity length, number of primary branches per vine and total soluble solids content. D2 analysis grouped the accessions into ten clusters. The reference accessions obtained from USA and land races collected from different agro-ecological zones of India were found to be scattered in different clusters. No parallelism was found between genetic and geographic diversity. DNA polymorphism was utilized to cluster the genotypes into different clusters based on similarity as well as dissimilarity coefficients. On basis of SSR analysis, dendrogram clustered 96 accessions into three major groups. There was a significant correlation between botanical groups and the clustering pattern. Accessions belonging to cantalupensis cluster together in cluster I, accessions of reticulatus group cluster together in cluster II and momordica group cluster together in cluster III. However, some accessions of cantalupensis and reticulatus were intermixed in cluster I and II. Reference accessions cluster together forming a genetically unique assemblage in subgroup IIA and shared similarity coefficient of 0.65 with sub-group IIB. This suggested that reference accessions shared genetic affinities with Indian melon accessions that could not have been predicted based on their geographic origin. Four accessions were free from CMV and two accessions exhibited immune reaction to downy mildew. The results inferred that these melon accessions could be used to broaden the genetic base of melon.ThesisItem Open Access Molecular mapping of nuclear male sterility gene ms10 in chilli pepper (Capsicum annuum L.)(Punjab Agricultural University, Ludhiana, 2016) Aulakh, Parjeet Singh; Dhaliwal, M.S.Most of the hybrid seed in chilli is produced manually, but use of male sterility (MS) systems can reduce cost of hybrid seed production. ‘MS-12’, a nuclear male sterile (NMS) line developed at Punjab Agricultural University, Ludhiana (India) has been utilized to develop three commercial F1 hybrids. A recessive gene designated as ms10 governs MS in ‘MS-12’. Due to recessive gene control, development of new NMS lines through the conventional backcross method is tedious and time consuming. Therefore, the present investigation was planned to identify molecular markers linked to the ms10 gene and to initiate transfer of ms10 gene into an array of elite breeding lines through marker assisted selection (MAS). Two genetically diverse parents ‘MS-12’ and ‘VR-16’ were crossed and F1 was selfed to generate F2 mapping population. A total of 558 simple sequence repeat (SSR) primer pairs were screened for parental polymorphism following bulk segregant analysis (BSA). Linkage analysis indicated that two SSR markers AVRDC- PP12 and AVRDC_MD997* were linked to the ms10 gene. Marker AVRDC-PP12 was closest to the gene at 7.2 cM distance and the marker AVRDC_MD997* was mapped at 20.8 cM from the gene. The two markers were mapped on pepper chromosome 1 at genome position 175,694,513 to 175,694,644 and 175,438,699 to 175,438,872 respectively. In backcross progenies, the marker AVRDC-PP12 distinguished the heterozygote fertile (Ms10ms10) from the homozygous dominant fertile (Ms10Ms10) plants in three segregating backcross progenies incorporated with ms10 gene. Thus, the marker AVRDC- PP12 can efficiently be used to transfer ms10 gene for marker assisted backcrossing to save time and resources. The markers provide further perspectives for fine mapping and map based cloning of the ms10 gene.