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20133
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Subject: Horticulture × End date: 2013 × Start date: 2013 ×
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    ThesisItemOpen Access
    MORPHOLOGICAL AND MOLECULAR CHARACTERIZATION OF GERMPLASM AND F1 HYBRIDS.
    (PAU Ludhiana, 2013) Daljinder Singh; M. I. S, . Gill
    The 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.
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    ThesisItemOpen 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.
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    ThesisItemOpen Access
    Effect of pre-harvest sprays of ascorbic acid and calcium chloride on fruit quality and storage life of Flame Seedless grapes (Vitis vinifera L
    (Punjab Agricultural University, 2013) Niraj Kumar
    The present investigations entitled “Effect of pre-harvest sprays of ascorbic acid calcium chloride on fruit quality and storage life of Flame Seedless grapes (Vitis vinifera L.)” were carried out in the New Orchard and Post-harvest Laboratory, Department of Fruit Science, Punjab Agricultural University, Ludhiana during 2012. To improve quality and storage life the pre-harvest prays of ascorbic acid and calcium chloride was given at fruit-set and veraison stage in treatment T1 to T6. The treatment T7 (Bunch thinning + GA3 40ppm) and T8 (75% crop load + Ethephon at verasion @ 400ppm) were also included for comparison. The fruits were harvested at fully ripe stage and brought to laboratory for ascertaining the effect on fruit quality and packaging in CFB boxes (2 kg) lined with LDPE having half sheet of sulphur dioxide generating pad for storage study. The time of ripening was advanced by 5-days in the treatment T8 (crop load 75% + ethephon 400 ppm) as compared to control, while in the treatment T7, in which bunch thinning + gibberellic acid 40 ppm was applied time of ripening was advanced by 3-days.The treatment T7 i.e. bunch thinning + gibberellic acid resulted in significantly higher yield (33.54 kg/vine) followed by treatment T8 (75 % crop load + Ethephon 400 ppm) which was recorded 31.05 kg fruit yield per vine. Likewise, improved fruit quality w.r.t to higher total soluble solids (TSS), lower acidity, higher sugars and anthocyanin content was also recorded in treatment T8 (75 % crop load + Ethephon 400 ppm).In the storage studies, the lowest mean PLW (3.54%) and berry shattering (8.43 %) was recorded in treatment T7 i.e. bunch thinning + gibberellic acid 40 ppm. The treatments in which 75 per cent crop load and 400 ppm ethephon was sprayed recorded maximum (8.00) mean palatability rating, followed by 7.87 palatability score found in treatment (T7) subjected to bunch thinning + GA3 (40 ppm) at the end of storage period. The TSS: acid ratio increased with the advancement in storage period. The highest mean TSS: acid ratio of 42.85 was recorded in treatment T8, i.e. crop load (75 %) + 400 ppm ethephon. The TSS: acid ratio mean was lowest (20.55) in control T9. The present study suggests that the pre-harvest application of 75 per cent crop load + ethephon (@ 400ppm at veraison) should be given for improvement in fruit quality and advancement in ripening in Flame Seedless grapes. While, for extending the storage life vines should be subjected to pre-harvest application of bunch thinning and application of GA3 @ 40 ppm at fruit-set and one week after fruit-set.