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Subject: Genetics and Plant Breeding × End date: 2004 × Start date: 2004 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Study of genetic and molecular diversity in a collection of indigenous aromatic rice (Oryza sativa L.)
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2004-07) Sumita Kumari; Singh, Harpal
    Rice comprising of 22 wild and two cultivated species (O. sativa and O. glaberrima) is the staple food for more than one- third of the world populace. In recent years, there has been an increased number of genetically related varieties released by rice breeders which has resulted in limited levels of genetic diversity. Information on the extent of genetic diversity among accessions is needed to harness the germplasm and thus, make use of the available genetic resources to create new accessions. Therefore, the present investigation of “Study of genetic and molecular diversity in a collection of indigenous aromatic rice” was carried out in aromatic rice to study genetic diversity through Mahalanobis D2 statistic and Microsatellite or simple sequence repeat markers. Forty indigenous aromatic rice genotypes and one non- aromatic check displayed considerable diversity on agromorphological data and quality traits. On the basis of Mahalanobis D2 statistic ten clusters were formed. Cluster I comprised of 13 genotypes, cluster II had 12 and cluster III and IV contained five genotypes. Cluster V, VI, VII, VIII, IX and X contained one genotype each. It was found that geographical diversity need not necessarily be related to the genetic diversity. Molecular diversity delineated by 15 microsatellite (SSR) markers revealed high level of divergence. A total of 83 bands were amplified of which 79 were polymorphic. The dendrogram generated from data derived from fragments amplified by primers clearly separated the aromatic group of rice from non- aromatic check Pant Dhan- 12. Aromatic rice genotypes were classified in two groups, cluster I had 2 and 38 genotypes were there in cluster II. But clusters generated by D2 statistic were not able to distinguish the non- aromatic check instead it was grouped with 12 other aromatic rice genotypes in the cluster II. Thus, information content generated by microsatellite markers was more valuable. The hybridization between the genotypes falling in most distant clusters is expected to result in maximum hybrid vigor and higher number of useful segregates.
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    ThesisItemOpen Access
    Studies on genetic evaluation and correlation for nodulation and yield attributing traits in rabi soybean (Glycine max (L.) Merrill)
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2004-07) Vikash Kumar; Singh, Brij Vir
    The present investigation was carried out at Crop Research Centre of G.B. Pant University of Agriculture and Technology, Pantnagar, during Rabi season in the year, 2002-03. The experimental material was consisted of thirty three early maturity varieties and breeding lines of soybean suitable for Rabi season. The experiment was laid out in a Factorial Randomized Block Design (Factorial RBD) with two factors in three replications. Two factors were: Genotypes of soybean and Bradyrhizobium japonicum strain P2 inoculation with no-inoculation (control). Single row of non leguminous barley seeds were also sown. The objective of the present study was to determine genetic variability and their interaction present in the experimental material with respect to yield attributing traits and nodulation in soybean genotypes. It was also aimed to find out coefficient of variability, heritability and genetic advance and correlation between different yield attributing traits and nodulation parameters. The observations were recorded on seventeen yield attributing traits and nodulation. Highly significant differences were observed due to inoculation, genotypes of soybean and interaction between genotypes and inoculation for all the characters except, for days to flower initiation, days to fifty per cent flowering and days to maturity, where only genotypic mean were significant. Inoculation gave significantly highest gain for nodule volume per plant among nodulation parameters and number of primary branches per plant among yield traits. Genotypes i.e., PBL 20, PBL 18, PBL 15 and PBL 11 under inoculated condition and genotypes i.e., PBL 8, PBL 9 and VLS 58 under non-inoculated condition performed better for yield attributing traits. For nodulation parameters, genotypes i.e., PBL 5, Himso 1599, PBL 21, PBL 14 and PBL 3 under inoculated condition and genotypes PBL 16, PBL 17 and PBL 2 under uninoculated condition nodulated better than others. GCV was lower than PCV for all the characters. Correlation study revealed that seed yield per plant correlated positively and significantly with all the yield attributing traits. Nodulation parameters had highly significant positive correlation among themselves except between nodule weight per plant and percent of nitrogen fixed. Character association between nodulation parameters and yield attributing traits were positive and non-significant in most of the cases except for maturity traits, plant height and number of primary branches per plant where results were positive and significant. This needs confirmation keeping in view the conflicting reports by incorporation of different nodulation parameters or taking different approaches. Oil content which had a negative correlation with almost all the traits particularly with protein content. Results of heritability estimates and character association showed that selection criteria based on nodule weight per plant, nodule number per plant, number of seeds germinated, plant height, number of pods per plant, 100-seed weight, number of seeds per pod and number of primary branches per plant would be highly effective and have major contribution in determining seed yield in all the thirty three genotypes of soybean.