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ThesisItem Open Access MORPHOLOGICAL AND MOLECULAR CHARACTERIZATION OF GERMPLASM AND F1 HYBRIDS.(PAU Ludhiana, 2013) Daljinder Singh; M. I. S, . GillThe present investigation entitled “Morphological and molecular characterization of guava (Psidium guajava L.) germplasm and F1 hybrids” was conducted during years 2010 to 2013 at P.A.U., Ludhiana and Regional Fruit Research Station, Bahadurgarh. Thirty five guava genotypes grafted on seedling rootstocks were evaluated for tree, vegetative, reproductive, fruit and seed characters based on UPOV descriptors. Statistically significant difference for all the traits was observed among tested genotypes. Among components of genetic variation, phenotypic and genotypic coefficient of variation for different traits ranged from 7.26 and 6.95 to 35.00 and 33.11 %, respectively. Divergence analysis based on D2 statistic grouped the tested genotypes into six clusters with variable number of genotypes in each cluster, indicating the presence of genetic diversity in them. Cluster I, cluster IV, cluster V and cluster VI showed intra cluster distance of 55.12, 55.40, 50.70 and 61.84 respectively, indicating sufficient dissimilarity among genotypes for morphological features. Molecular characterization using 80 SSR primer pairs was done enabling cluster analysis of 43 guava genotypes. Among the primers, 78 markers amplified 258 alleles across the 43 genotypes with an average of 3.25 alleles per locus. The highest number of seven alleles per locus was amplified by mPgCIR 32, followed by six alleles per locus by mPgCIR98. The power of discrimination was found to be least (0.00) for markers mPgCIR251 and mPgCIR 414 and highest (0.84) for markers mPgCIR137. Values of expected heterozygosity ranged from 0.00 in monomorphic locus (mPgCIR251 and 414) to maximum 0.79 for locus mPgCIR32, with an average 0.47 expected heterozygosity. Estimated genetic dissimilarity coefficient ranged from minimum 0.020 (between genotypes 14-10 and 12-11) to 0.590 (between One Kg and Portugal) with an average dissimilarity of 0.322 across all the genotypes. Cluster analysis on the basis of molecular analysis classified the guava genotypes into two major groups having 3 and 40 genotypes each. The dendrogram generated using SSR markers along with the phenotypic data will be useful for choosing the diverse parents for further guava breeding programmes. A total of nine F1 hybrids were generated and vegetative parameters were recorded in different hybrids to distinguish them, as well as SSR markers were also used to confirm the parentage of these hybrids.ThesisItem Open Access Assessment of genetic divergence and hybridization studies in pomegranate germplasm(PAU, 2013) Raina, Dimpy; Gill, P.P.S.The present investigation entitled ―Assessment of genetic divergence and hybridization studies in pomegranate germplasm‖. The objectives of this study were to assess genetic diversity based on horticultural traits, characterization of pomegranate genotypes using DNA markers, effectiveness of pollen storage conditions and exploration of the possibilities of F 1 hybrid production during year 2011-12. A significant and wide range of variation was observed among genotypes for various quantitative characters. Higher coefficient of variation was observed for characters like number of hermophrodite flowers per tree (26.67), number of fruits per tree (20.55), yield per tree (22.73), acidity (11.62) and TSS/acid ratio (13.23). ‗Ganesh‘ recorded maximum yield (21.16 kg/plant), fruit weight (309.3 g), aril weight (31.62 g /100 aril weight), peel weight (103.42 g) and TSS (13.39 %) but with minimum juice per cent (28.54 %). Mridula was observed promising for fruit length (6.75 cm), fruit breadth (7.85 cm), TSS/Acid ratio (51.18) and less in acidity (0.26 %). Highest juice per cent (67.26) and lowest TSS (11.0 %) was found in ‗Anar Shirin‘. Jhodpur White had highest number of hermophrodite flowers (338.3) and fruits per tree (60.84). The yield per tree was found correlated positively with fruit weight, aril weight and peel weight and negatively with juice per cent. The clustering of genotypes into eight different clusters was based on mean values of quantitative characters. The maximum inter -cluster distance of 72.74 was observed among genotypes of the cluster V and VII and minimum (23 .85) between the cluster IV and III. The principal component analysis showed that more than 82 per cent of the variability observed for quantitative characters in different pomegranate genotypes. Genetic divergence among the genotypes was estimated by 47 SSR markers. Six SSR markers (Pom010, ABRII-MP28, PGCT046, PGCT088, PGCT112 and PGCT037) showed monomorphic pattern and 41 showed polymorphic patterns with amplification of alleles ranging from 2 to 4. PIC value ranged from 0 and 0.66 (PGCT093) among 41 polymorphic primers. The UPGMA clustering grouped the genotypes into three main clusters I, II and III. The cluster I comprised of one genotype followed by the cluster II which contained eight genotypes, whereas, sub-cluster IIIA contained 12 genotypes, five and four in sub-cluster IIIB and IIIC, respectively. Genetic similarity values between genotypes ranged from 0.78 to 0.95 and dissimilarity was only 0.17. Maximum pollen viability was observed at -200 C storage temperature for 9 weeks and highest viable pollens found in Ganesh (95 %) followed by ‗Mridula‘ (94.7 %), ‗Jyoti‘ (92.7 %) and ‗Kandhari‘ (92 %). Highest pollen germination was recorded in Ganesh (78.9 %) followed by ‗Mridula‘ (75.8 %), Jyoti (58.9 %) and minimum in ‗Kandhari‘ (51.6 %). In hybridization study of pomegranate genotypes 80.47 per cent success rate in terms of fruit set after crossing was achieved. Highest fruit set observed in ‗Mridula‘ x ‗Ganesh‘ (85.54%) and lowest in ‗Mridula‘ x ‗Kandhari‘ (76.61 %). Five SSR primer pair (PGCT093, PGCT059, PGCT097, PGCT111, and ABRII-MP42) was found to produce the polymorphic alleles to confirm the hybridity of hybrids.ThesisItem Open Access Effect of pre-harvest application of nutrients and growth regulator on storage life and quality of peach cv. Shan-i-Punjab(Punjab Agricultural University, Ludhiana, 2012) Arvind Preet KaurThe present investigations entitled, “Effect of pre-harvest application of nutrients and growth regulator on storage life and quality of peach cv. Shan-i-Punjab” were carried out in the Department of Horticulture PAU, Ludhiana during the years 2010 and 2011. Peach trees of cv. Shan-i-Punjab were sprayed with CaCl2, Boric acid and KNO3 (all at 1.0, 2.0 and 3.0 per cent) and GA3 (20, 40 and 60 ppm), one and two weeks before harvesting. Fruits after harvesting at hard mature stage were transported to the laboratory. The fruits of uniform size and free from diseases, bruises were selected, washed, dried, packed in CFB boxes and kept upto 35 days in cold stores and 6 days under ambient conditions. The cold stored fruits were analyzed after 24, 48 and 72 hrs at different storage intervals. 2.0 per cent KNO3 advanced fruit maturity and improved fruit quality in terms of TSS, size, weight, colour and palatability rating. During cold storage, 2.0 per cent CaCl2 treated fruits helped in reducing PLW, spoilage, fruit colour degradation and improved fruit quality. Phenolic content decreased whereas carotene content and activity of PME increased with the advancement of storage period in all the treatments. The levels of N, K, B and Ca both in leaves and fruits were higher in the treatments where the respective chemicals were applied. The shelf life of cold stored fruits declined rapidly after 24 hrs in all the treatments. Under ambient storage, 2.0 per cent CaCl2 helped in reducing PLW with average fruit quality upto 2 days. The present study showed that the fruits treated with 2.0 per cent CaCl2 can be stored upto 28 days of cold storage without any spoilage and good palatability rating.
