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20134
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Subject: Crop Physiology × End date: 2013 × Start date: 2013 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Studies on physiological and biochemical changes during long term storage of paddy and rice under different packaging materials
    (UAS Dharwad, 2013) D. Saida Naik; M. B. Chetti
    Investigations were undertaken to study the physiological and biochemical changes during long term storage of paddy and rice under different packaging materials at the Department of Crop Physiology, College of Agriculture, University of Agricultural Sciences, Dharwad over a period of 18 months from February, 2011 to August, 2013. The research study consisted of two experiments with eight treatments comprising packing of seeds with different packaging materials viz., vacuum packed, , polythene, cloth and gunny bags stored at room temperature (25±2º C) and cold storage (4±1º C) for a period of 18 months. The observations recorded at bi-monthly intervals revealed that the seeds stored in vacuum packed bags maintained the quality with least deterioration compared to gunny and cloth bags. The seed quality parameters viz., germination per cent, root length, shoot length, total seedling length, seedling dry weight, seedling vigour index, mean daily germination and mobilization efficiency were very high in vacuum packed bags compared to gunny bags throughout the storage period of 18 months under both ambient and cold storage. Electrical conductivity values were lowest in vacuum packed bags compared to polythene, gunny and cloth bags. The rate of absorbance of moisture content was more in gunny and cloth bags, while vacuum packed bags maintained constant moisture content. The activities of enzymes viz., a- amylase, lipase, protease and peroxidase were slightly less in vacuum packed bags compared to gunny and cloth bags in both paddy and rice grains. Mineral contents viz., copper, zinc, iron and manganese decreased with advancement in storage period and higher in vacuum packed seeds over all other treatments in both paddy and rice grains. Among the storage conditions, cold storage recorded better seed quality, physiological and biochemical parameters over room temperature, irrespective of the storage containers throughout the storage period of 18 months.
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    ThesisItemOpen Access
    Influence of 1-methylcyclopropene (1-mcp) on post harvest physiology and physico-chemical changes in alphonso mango (mangifera indica l.)
    (UAS Dharwad, 2013) Arun Vasant Mane; M. B. Chetti
    Investigation were carried out to find out the influence of 1-MCP (1- methylcyclopropene) on physical, physiological and physico-chemical changes and ripening behaviour in Alphonso mango (Mangifera indica L.) during 2011 and 2012 at the Department of Agril.Botany, College of Agriculture, Dr.BSKKV, Dapoli. The experiment consisted of 16 treatment combinations comprising 4 concentrations of 1-MCP and 4 storage conditions. Results revealed that fruits ripened early under ambient condition without 1-MCP treatment. Fruits under cold storage with 2000 ppb of 1-MCP exhibited significantly longer retention of green colour, firm texture and slow rate of loss in physiological weight, thereby delaying ripening compared to ambient condition. Total soluble solids, total sugars, reducing sugars increased and vitamin-A, titratable acidity and ascorbic acid content decreased rapidly until 14 DAT (days after treatment) under control and 21 days under cold storage with 2000 ppb of 1-MCP. There was a gradual rise in ethylene production till 14 DAT followed by decline at 21 DAT under ambient condition. The rate of fruit respiration was significantly higher under ambient condition compared to other treatments and the lowest was recorded in cold storage with 1-MCP (2000 ppb). Cold storage with 1-MCP showed gradual increase in total carotenoids till the end of storage period as against rapid increase under ambient condition. Ambient condition recorded maximum number of spongy affected fruits and the lowest was noticed with higher concentration of 1-MCP (2000 ppb) in cold storage. There was a constant degradation of chlorophyll under ambient condition throughout the study period; while, cold storage with 2000 ppb 1-MCP maintained significantly higher values till 26 DAT. The present findings clearly establish that cold storage with 1-MCP @ 2000 ppb holds a great potential in delaying fruit ripening ultimately prolonging the post harvest storage and shelf life by 10 – 12 days.
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    ThesisItemOpen Access
    Identifying drought tolerant cotton (gossypium hirsutum l.) genotypes by physiological and molecular approaches
    (UAS Dharwad, 2013) Babu A. G.; B. C. Patil
    A field experiment was conducted during 2011-12 for the evaluation drought tolerance using thirty Gossypium, hirsutum L. genotypes in RBD design at ARS Dharwad and ARS Annigeri. Ten best (CPD-750, Sahana, ARB-9701, CNH-120MB, GIHV-218, BS- 279, RAH-101, GJHV-477, F-2228 and KH-155) and two least (L-761 and LH-2076) performed genotypes were selected from these experiments based on drought tolerant physiological traits viz. SLW, water potential, SPAD values, gas exchange parameters and yield. Simultaneously 600 cotton germplasms lines were also evaluated for drought tolerance by physiological traits at ARS Dharwad. Based on the SPAD, SLW and gas exchange parameters 24 germplasm lines were showed significantly on par for the most of the physiological traits. During 2012-13, the selected twelve genotypes were evaluated for performance under different concentrations of PEG-6000 osmotic solutions at germination stage by slanting glass plate technique. The germination %, shoot length, seedling vigour index and shoot vigour index decreased as the PEG 6000 concentration increase from 0% to 27% in all genotypes, while the root length and root: shoot ratio increased. These genotypes were further evaluated at rain out shelter for drought tolerance by morphological, physiological, biophysical, biochemical, root architecture (length, volume and lateral roots) yield, yield components and fibre properties. The genotypes viz. CPD-750, Sahana, ARB-9701, CNH- 120MB, GIHV-218, and BS-279 were found relatively drought tolerant. Further these twelve genotypes were studied for genetic diversity study using 79 cotton specific RAPD molecular markers. There was 79.56 per cent genetic polymorphism/diversity. The primers OPI 4 and OLIGO 652 amplified 800 bp and 400 bp respectively were specific to relatively drought tolerant genotypes. The dendrogram revealed that the primers were able to group the genotypes in to three major clusters. From the overall present investigation, the genotypes viz. CPD-750, Sahana, ARB-9701, CNH-120MB, GIHV-218, BS-279 and RAH-101 were identified as drought tolerant lines.
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    ThesisItemOpen Access
    Physiological Basis of Zinc Biofortification in Bread Weeat (Triticum aestivum L.)
    (UAS Dharwad, 2013) Raghavendra T. R.; R. V. Koti
    Wheat serves as the main staple food for a large proportion of the world population but has the shortcoming, from a nutrition perspective, of being low in zinc and other essential nutrients. In an attempt to study the physiological basis of zinc nutrition, 298 NBPGR lines along with Lok-62 and C-306 were screened for grain zinc content. The grain zinc content ranged from 5-45 mg kg-1. Twenty seven lines (6 low, 7 medium and 14 high lines) were field evaluated using factorial RBD with 3 treatments (control, with soil application of zinc sulphate @ 10 kg ha-1 and with foliar application twice at 30 and 60 DAS @ 0.5%) for various physiological, biochemical and quality parameters during rabi 2011-12 and 2012-13. Results revealed that foliar application of zinc increased leaf area, TDM, SPAD values, chlorophyll content, grain yield and grain and leaf zinc content compared to soil application and control irrespective of germplasm lines. Foliar application of zinc increased leaf zinc content at pre and post anthesis period, which lead to higher zinc content in grains. The anti-oxidative enzymes such as superoxide dismutase (SOD) and peroxidase (POX) activity increased significantly due to foliar application of zinc and showed that increased zinc has got the mechanism to counter the ill effects of active oxygen species. In addition to increase in grain zinc content, there was increase in grain protein, gluten and zeleny content revealed beneficial effect of foliar application of zinc sulphate. The lines 636, 127, 606 and Lok-62 are the probable better germplasm lines with high grain zinc and fairly good amount of grain yield. The lines viz., 554, 12, 734, 279, 422, 127, 723 and 822 are more zinc efficient than others with ability to grow and maintain yield under low zinc availability. Foliar application of zinc sulphate can be a better option in mitigating the zinc deficiency both from the context of plant and human nutrition.