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2014 - 20155
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Subject: Horticulture × End date: 2016 × Start date: 2010 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    MORPHOLOGICAL AND BIOCHEMICAL CHARACTERIZATION OF BHUT JOLOKIA (Capsicum chinense Jacq.)
    (AAU, Jorhat, 2015) Sentimenla; Narzary, B. D.
    An experiment was conducted during the year 2012-13 and 2013-14 in the Experimental Farm, Department of Horticulture, College of Agriculture, Assam Agricultural University, Jorhat on eleven Bhut jolokia (Capsicum chinense Jacq.) genotypes for morphological and biochemical characterization. Observations were recorded for morphologic traits, growth characters, yield and yield attributing traits, biochemical characters and colour parameters. Characterization of the genotypes was done based on 11 morphological characters following the descriptors developed by the International Plant Genetic Resources Institute for the genus Capsicum, IPGRI (1995).The genotypes were characterized by the 11 morphological characters, of which only 4 characters showed polymorphism. Significant variation was revealed among the genotypes for all the growth and yield and yield attributing characters except for 1000 seed weight. The highest fruit yield per plant with the highest number of flowers per cluster, minimum days to emergence of flower bud, highest number of fruits per plant and maximum days to harvest maturity was produced by G9 compared to other genotypes. Among the other genotypes G1, G6 and G10 were found promising for fruit yield. All the genotypes showed significant variation with regard to the biochemical characters except moisture content. Genotypes G1 showed the highest content for potassium, iron, capsaicin, moisture and DPPH scavenging activity. It was observed that the crude protein, beta-carotene and oleoresin content were highest in G3 compared to the other genotypes. G6 gave the highest value for ascorbic acid and phosphorus content compared to the other genotypes under study. From the colour value estimation it was found that genotype G3 exhibited the highest ‘L’ and ‘a’ value while G4 showed the highest value for ‘b’ and hue compared to the other genotypes and the highest value for Chroma was recorded in G9. From the study of genetic parameters in this population of genotypes, it was observed that fruit yield per plant showed the highest genotypic variation, heritability and genetic advance. The other characters found to be effective selection criteria were plant height, number of leaves per plant, number of fruits per plant and number of seeds per fruit. From Path analysis it was found that the number of primary branches and fruit width exerted positive direct effects and were positively correlated with fruit yield per plant. Thus by considering both genetic parameters and character relationships number of leaves per plant, days to emergence of flower bud, fruit width, number of primary branches per plant, number of fruit per plant and harvest duration could be further exploited for crop improvement to develop suitable plant type. Thus considerable variation observed among the genotypes for various yield attributes suggested good scope for developing high yielding varieties through selection and hybridization. Moreover identification and characterization of bhut jolokia genotypes is essential for protection of plant varieties and for maintenance breeding, seed production and certification.
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    ThesisItemOpen Access
    GENETIC DIVERSITY IN IVY GOURD [Coccinia grandis (L.) Voigt.] GENOTYPES OF NORTH EASTERN REGION BASED ON MORPHOLOGICAL AND RAPD MARKERS
    (AAU, Jorhat, 2014) Saikia, Jumi; Borbora Phookan, Deepa
    An experiment was conducted to study the genetic diversity in ivy gourd [Coccinia grandis (L.) Voigt.] genotypes collected from different parts of Assam and other North Eastern States (Arunachal Pradesh, Tripura and Nagaland) during the summer seasons of 2013 and 2014. The experiment was laid out in Randomized Block Design with three replications at the Experimental Farm, Department of Horticulture, Assam Agricultural University, Jorhat. Morphological characterization of 22 genotypes revealed significant variation among the genotypes. The mean performance of genotypes for quantitative traits revealed that the genotype IG-23 recorded maximum for fruit characters viz., fruit length (8.50 cm), fruit weight (33.62 g) and fruit yield per plant (8.66 kg). Whereas IG-22 exhibited the highest number of primary branches (7.35), fruit width (3.03 cm) and number of fruits per plant (391.83). Promising genotypes were IG-10, IG-18, IG-22 and IG-23. Genetic variability in terms of PCV and GCV were high for yield per plant (27.56% and 23.87%, respectively). High heritability in broad sense combined with high genetic advance was recorded for number of fruits per plant (94.39%, 38.57%) followed by fruit weight (93.36%, 32.61%) which were indicative of preponderance of additive and additive x additive type of gene interaction. The correlation analysis revealed that yield per plant had significant positive correlation with number of primary branches, fruit length, number of fruits per plant and fruit weight. From the path coefficient analysis, it was observed that number of fruits per plant had the highest positive direct effect (1.1928) on yield. Number of primary branches had the highest positive indirect effect on yield via number of fruits per plant (1.1491). The residual effect was 0.1097 which was within a reasonable limit indicating that the characters included in path coefficient analysis were adequate in explaining the variation in ivy gourd. Genetic diversity using Mahalanobis’s D2 statistic grouped the genotypes into 6 clusters following the method suggested by Tocher. Among the 6 clusters the intra-cluster distance varied from 0.00 to 3.48 and maximum inter-cluster distance was observed between cluster IV and cluster V (7.83). Cluster IV showed desirable values for number of primary branches (6.66), peduncle length (2.27 cm), fruit length (7.10 cm), number of fruits per plant (302.83), fruit weight (28.92 g) and yield per plant (7.55 kg). The most important characters contributing towards divergence were fruit weight (37.23% contribution) followed by number of fruits per plant (30.30%). D2 analysis revealed that the pattern of distribution of genotypes from different locations into different cluster was random. At molecular level, 25 random decamer primers generated a total of 124 amplification products of which 52 bands were polymorphic. Total polymorphism was 41.94%. The extent of polymorphism was higher with RAPD primers such as OPB-08 (83.33%), OPC-01 (71.43%) and OPD-05 (66.66%). The dendrogram showed that UPGMA cluster analysis grouped the genotypes into 4 major clusters. In cluster I, only one genotype i.e. IG-14 was included which was out grouped from the rest of the genotypes. A fairly wide range of Jaccard’s similarity coefficient (0.10 to 1.09) was observed which indicated high level of genetic diversity. Among the nutritional traits, highest protein content (1.41 g/100 g) as well as iron (2.75 mg/100 g) were recorded in IG-22. Ascorbic acid (27.05 mg/100 g) and carotene (189 g/100 g) were found to be highest in IG-18. IG-23 recorded the highest crude fibre content (1.97%) and total ash content (6.78%).
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    ThesisItemOpen Access
    Morpho-biochemical characterization of Garcinia species of Assam
    (AAU, Jorhat, 2015) Gogoi, Bornali; Dr. R. P. Das
    An investigation was conducted during the period of 2012-14 to study the morpho-biochemical characterization of Garcinia species of Assam viz., Garcinia pedunculata Roxb, Garcinia cowa Roxb, Garcinia lanceaefolia Roxb and Garcinia xanthochymus Hook.f. The morphological parameters of plant, floral biology and biochemical composition of fruits were studied in healthy, bearing trees of uniform age from five locations of Jorhat district viz., Bahek gaon (L1), Charaibahi (L2), Atila gaon (L3), Chotai (L4) and Borbheta (L5). The five districts of Assam i.e. Dibrugarh, Sivsagar, Jorhat, Golaghat and Nagaon were selected purposively for ethno-botanical survey of the selected species. The ethno-botanical study revealed that majority of people uses the fruits of all the four species for different purposes than the seed, leaf and bark. However, most of the people from the five districts used these Garcinia plant as a source of medicine and for some social customs. Non significant difference was found in plant height of each species. However, plant height of G. pedunculata is highest (22.40 m) among the four species in which flowering occurs twice in a year i.e. once at last week of October to first week of November and another at last week of April to first week of May. Whereas in other species flowering occurred only once in a year. Duration of flowering was almost same in all the species and the maximum (52 days) was observed in G. xanthochymus and the minimum (42 days) was recorded in G. lanceaefolia. Anthesis took place early in the morning in all the species and the time period was from 1.00 A.M. to 6.00 A.M. Wide variations were observed in fruit weight and volume. The G. pedunculata exhibited highest (620.80 g) fruit weight whereas G. lanceaefolia exhibited lowest (22.51 g) fruit weight. In respect of number of seeds per fruit G. pedunculata had 9.35 numbers of seed whereas G. xanthochymus showed 2.50 numbers of seed. The moisture content was found to be highest (92.91%) in G. cowa and ascorbic acid content ranges from 35.37mg/100 g to 88.92 mg/100g and the highest was found in G. pedunculata and the lowest in G. lanceaefolia respectively. The total phenol content was highest (3.68%) in G.xanthochymus the lowest (1.89%) was recorded in G.cowa whereas total ash content was found highest (2.18%) in G. lanceaefolia. Reducing sugar content of all the four species were found to be in a lower range and no significant difference was observed among the locations of each species in terms of total carbohydrate and energy value. Total carbohydrate ranges from 50.75 per cent to 57.90 per cent and energy value ranges from 224.57Kcal/100 g to 245.49 Kcal/100 g, respectively. On the other hand total antioxidant activity was recorded to be highest in G. xanthochymus (9.45%) and the lowest (5.22%) was recorded in G. lanceaefolia. However, HCA content was highest in G. cowa (1.48%). Karyotype study revealed that chromosome number of G. pedunculata, G. cowa and G. lanceaefolia was found to be 2n=48 whereas G. xanthochymus had 2n=72 numbers of chromosome. The biochemical analysis of the present study will help to enrich diet formulations and nutraceuticals. The karyotype analysis and morphological study gives a scope for genetic assessment and breeding due to the presence of variability in different characters.
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    ThesisItemOpen Access
    SHELF LIFE ENHANCEMENT OF KEW PINEAPPLE AND KHASI MANDARIN USING BIOTIC POLYMER, MICROBIAL ANTAGONIST AND UV RADIATION
    (2014) Mili, Jyoti Prashad; Borthakur, P. K.
    Studies were carried out at Department of Horticulture, Assam Agricultural University during the period 2012-2014 with an objective to study the effect of biotic polymer, microbial antagonist and UV radiation on shelf-life of Khasi mandarin and Kew pineapple fruits and to study the economics of using the treatments. The study revealed that decay of fruits was mainly caused by Penicillium digitatum, P. niger, P. chryogenum and Aspergillus niger on Khasi mandarin and Penicillium sp., Aspergillus niger, Fusarium subglutinas, Nigrospora sp. on Kew pineapple. The decay percentage, PLW, pH, TSS, acidity and peroxidase enzyme activity of Khasi mandarin and Kew pineapple fruits increased with increase in the period of storage while texture value, fruit weight, moisture content, ascorbic acid and chlorophyll content decreased during storage period. Amongst all the UV treatments; UV radiation and chitosan combined treatment (T9) was found most effective in retention of shelf life. UV radiation and Pseudomonus combined treatment (T12) and Bacillus and Pseudomonus combined treatment (T8) had best result in most of the microbial antagonist treatments on Khasi mandarin and Kew pineapple fruits, respectively. Chitosan treatment had produced the best result among all the treatments and helped in retention of fruit texture and colour, had lower decay percentage, lower enzymatic activity and retained overall better fruit quality in both Khasi mandarin and Kew pineapple fruits during storage. This might be due to the properties of chitosan which not only has antimicrobial properties but also has the ability to form coating on fruit and vegetable surface, reducing the respiration rate by adjusting the permeability of carbon dioxide and oxygen. The UV radiation treatment showed less impressive results as compared to chitosan treatment. This was due to the free radicals generated from UV radiation might target cell membranes, nucleic acids, cell walls and enzymes, inducing the acceleration of senescence. The chitosan treatment was found to be the best in enhancing shelf life in both Khasi mandarin and Kew pineapple fruits during storage.
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    ThesisItemOpen Access
    Uni-packaging for shelf life extension of Khasi mandarin (Citrus reticulata Blanco.
    (AAU, 2015) Bhuyan, Namita; Baruah, P. C.
    A laboratory experiment was carried out in the Quality Control and PHT Laboratory, Department of Horticulture, Assam Agricultural University, Jorhat during 2012-2014, to study the effect of packaging materials, storage conditions and different altitudes on quality and storability of Khasi mandarin. The fruits were harvested at physiologically mature, i.e. colour break stage from three different altitude viz., relatively high altitude, medium altitude and low altitude. Healthy fruits were treated with 100 ppm sodium hypo chloride solution for 2 minutes. After drying the fruits in shade, fruits were uni-packed in different perforated packaging films viz., low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), polyvinyl chloride (PVC) and polyolefin films. The film-packed fruits were then stored under ambient (22-27°C and 70-75% RH), A.A.U developed semi-underground evaporative cool chamber (17-24°C and 89-90% RH) and cold storage conditions (6°C and 68-72% RH). The various physico-chemical and sensory attributes of fruits were recorded at weekly intervals during the entire storage period. Among the packaging materials, fruits packed in perforated HDPE films retained the highest sensory and nutritional quality (ascorbic acid, total carotenoid and pectin content) with slow and steadier change in the respiration rate, ethylene evaluation, PME activity, moisture content, titrable acidity and weight loss as compared to control (unpacked fruits). In all the packaged fruits under different storage conditions, the value of CCI (Citrus colour index) increased with progress of storage period. Fruit packed in perforated HDPE films under cold storage registered lower CCI value (1.66) compare to other packaging materials and storage conditions. Highest value was recorded in unpacked fruits (3.01) under cold storage condition. Higher amount of juice per cent was found in low altitude fruits but acidity and vitamin C was lower as compared to high altitude fruits. From the sensory quality study, it was observed that higher and medium altitude fruits packaged with perforated HDPE films scored the highest values on colour, texture, flavour and overall acceptability under all the storage conditions during the entire storage period. The lowest acceptability and sensory quality was registered in lower altitude fruits without packaging films. Individual Khasi mandarin fruit packed with perforated HDPE films can be successfully stored for 32 days under ambient condition, 40 days under evaporative cool chamber and 59 days under cold storage condition with highly acceptable sensory quality. The control (unpacked) fruits, on the other hand, maintained postharvest shelf life of 15, 28 and 37 days under ambient condition, evaporative cool chamber and cold storage condition, respectively. These results indicate that use of perforated HDPE films can prolong the shelf life by maintaining quality attributes and external appearance of Khasi mandarin fruits and hence extend their marketing period.