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University of Agricultural Sciences, Bengaluru
University of Agricultural Sciences Bangalore, a premier institution of agricultural education and research in the country, began as a small agricultural research farm in 1899 on 30 acres of land donated by Her Excellency Maharani Kempa Nanjammanni Vani Vilasa Sannidhiyavaru, the Regent of Mysore and appointed Dr. Lehmann, German Scientist to initiate research on soil crop response with a Laboratory in the Directorate of Agriculture. Later under the initiative of the Dewan of Mysore Sir M. Vishweshwaraiah, the Mysore Agriculture Residential School was established in 1913 at Hebbal which offered Licentiate in Agriculture and later offered a diploma programme in agriculture during 1920. The School was upgraded to Agriculture Collegein 1946 which offered four year degree programs in Agriculture. The Government of Mysore headed by Sri. S. Nijalingappa, the then Chief Minister, established the University of Agricultural Sciences on the pattern of Land Grant College system of USA and the University of Agricultural Sciences Act No. 22 was passed in Legislative Assembly in 1963. Dr. Zakir Hussain, the Vice President of India inaugurated the University on 21st August 1964.
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ThesisItem Embargo RELEVANCE OF STARCH HYDROLYSIS AS AFFECTED BY 1-DNJ, AN ALPHA-GLUCOSIDASE INHIBITOR IN SEEDS AND MESOPHYLL TISSUES OF MULBERRY(2022-12-18) ABHISHEK HIREWODEYAR; SAVITHA MADAPPAMulberry is often used as medicine in Chinese and Indian cultures, as it is known to contain many bioactive compounds. One such unique metabolite is 1-Deoxynojirimycin (1- DNJ), an iminosugar analogue to D-Glucose, making it a potent α-glucosidase inhibitor. This property has led 1-DNJ to be used in therapeutics and has been studied in mammalian systems. Present research outlines the investigation of 1-DNJ and its role in plant species. 1-DNJ being a known competitive inhibitor of α-glucosidase, its role in starch hydrolysis during seed germination and leaf starch hydrolysis at night time is hypothesized. This study reveals that the seed germination and seedling vigour of mulberry, rice and wheat seeds are affected in the presence of 1-DNJ with highest inhibitions of germination noticed in mulberry seeds and least inhibition in paddy seeds. However, starch hydrolysis at night in leaf is not affected, as 1-DNJ levels in leaf extract of mulberry are diurnally regulated. Studies on starch content and maltase enzyme (target of 1-DNJ) activity highlights that the starch content in DNJ or SA treated leaf gets reduced and maltase enzyme activity to be increased during night time similar to untreated control. Further, metabolites such as glucose, fructose and sucrose are increased in night in DNJ or SA treated leaves as in untreated leaves, in line with starch hydrolysis. Thus, the diurnal regulation of 1-DNJ content and its role in starch metabolism in mulberry is being reported for the first time. The similar study in contrasting genotypes would strengthen the present findings.ThesisItem Open Access INFLUENCE OF LEAF THICKNESS AND STOMATAL CHARACTERS ON WATER USE EFFICIENCY AND HAPLOTYPE MAPPING FOR VARIABILITY IN STOMATAL CHARACTERS IN RICE(2022-01-10) SOORYA, E.; Dr. SHESHSHAYEE, M S.Rice is the major food crops which serve as staple food for majority of the world’s population. Uneven rainfall and frequent droughts have brought the necessity to adopt aerobic cultivation. Water use efficiency (WUE) is an important physiological trait which determines the growth rates and has relevance under both resource sufficient as well as deficit conditions. WUE is a complex trait controlled by both photosynthesis and transpiration. Leaf thickness and stomatal frequency are two important traits that determine WUE through their influence on net assimilation rate (NAR) and mean transpiration rate (MTR), critical subcomponents of WUE. A study was conducted to evaluate 150 rice lines to screen for leaf thickness, stomatal frequency and leaf area. A sub-set of 32 lines were selected from 150 lines which were evaluated in phenomics facility under two water regimes i.e., well-watered (100% FC) and water-limited (60% FC) conditions. Leaf thickness was measured as leaf mass area (LMA) and stomatal frequency was determined using the leaf imprint method. Leaf area and WUE were strongly related in the selected sub-set. NAR was key determinant of WUE under both well-watered and water-limited conditions. Leaf thickness played a major role in determining WUE under water-limited condition, whereas WUE was better explained by stomatal frequency under well-watered condition. The probable reduction in mesophyll conductance in thicker leaves might be compensated by having many stomata. Haplotype analyses indicated presence of 3 haplotypes for each gene but were not responsible for phenotypic variation.ThesisItem Embargo STUDIES ON THE RELATIONSHIP OF CARBON TO NITROGEN RATIOS, SUGARS, AMINO ACIDS AND HORMONES WITH FLOWERING IN REGULAR AND IRREGULAR BEARING MANGO VARIETIES(2022-12-28) LOGESHWARAN, J.; SHIVASHANKARA, K. S.Mango fruiting is impacted by flowering and fruit set under unfavourable environmental conditions. Flowering is reported to be controlled by Carbon:Nitrogen ratio, more specifically by their individual concentration and the ratio is regulated by other factors such as hormones, minerals, amino acids, photosynthetic rate and also genotype. In this study, an attempt was made to understand the genotypic differences in flowering and its regulation. Genotypes differing in flowering were selected for the study. In addition to the genotypic differences, carbon accumulation variation was created using girdling and defoliation treatments. A total of 6 varieties, Alphonso, Langra, Dashehari from irregular and Amrapalli, Arka Anmol, Totapuri from regular bearing type were selected for the study. Number of vegetive and reproductive shoots were counted at frequent intervals. C and N content was analysed using CHNS analyser and other metabolites like sugars, amino acids, and hormones were estimated using LCMS. Higher Carbon content, more number of leaves, sucrose, fructose, ABA, SA, IAA, JA acted as positive regulators of flowering by generating more of generative shoots whereas the absence of leaves, GA3 were found to be negative controllers of flowering promoting vegetative shoot growth. Girdling has also influenced the accumulation of compounds and different leaf treatments altered the reserve storage by accumulating more Carbon. Study clearly indicated that the total carbon content rather than the C: N ratio plays an important role in induction of flowers which is influenced further by the flowering signals synthesised in the leaves.ThesisItem Embargo EFFECT OF ALTERED SOURCE SIZE ON YIELD ATTRIBUTING TRAITS IN FINGER MILLET(2022-12-10) CHAITHRA, B. S.; NANJA READDY, Y. AA field experiment entitled “Effect of altered source size on yield attributing traits in finger millet’’ was conducted in the field unit of the Department of Crop Physiology during summer, 2022. Study was conducted using varieties namely, GPU-45, GPU-28 and MR-6. Statistical design followed was FRBD with 9 treatments in 3 replications. The effects of source size (25%, 50%, 75%, and 100% leaf removal) on yield-contributing traits, grain yield, and seedling vigor were studied to determine the optimum source size and proportion of leaves on the plant for maximum grain yield. The reduced source size at flowering brought the crop to early maturity and decreased yield-contributing traits. However, the removal of 25% of leaves from bottom portion at flowering stage did not significantly decrease the yieldcontributing traits, hence, maintenance of the upper 75% of the leaves during post-flowering stage could be sufficient for maximum yield in finger millet, Correlation data showed that the source size (LAI) had a strong positive relationship with stem weight (0.806), total dry matter (0.847), test weight (0.645), finger number (0.554), mean car weight (0.417), and grain yield (0.642). Path analysis revealed a significant positive direct effect of the mean car weight (0.790) and productive tillers (0.510) on grain yield. The observed and estimated grain yields were not increased by increasing the LAI more than 4.0. Reduced source size reduced the seed size, and reduced seed size significantly decreased the seedling length, root/shoot ratio, and seedling dry weight. It is concluded that 75% of upper leaves with an LAI of 4.0 at flowering could be ideal for higher grain yield in finger millet, and the lower leaves are important during vegetative phase.ThesisItem Embargo RELEVANCE OF STARCH HYDROLYSIS AS AFFECTED BY 1-DNJ, AN ALPHA-GLUCOSIDASE INHIBITOR IN SEEDS AND MESOPHYLL TISSUES OF MULBERRY(2022-12-12) ABHISHEK HIREWODEYAR; SAVITHA MADAPPAMulberry is often used as medicine in Chinese and Indian cultures, as it is known to contain many bioactive compounds. One such unique metabolite is 1-Deoxynojirimycin (1-DNJ), an iminosugar analogue to D-Glucose, making it a potent α-glucosidase inhibitor. Thisproperty has led 1-DNJ to be used in therapeutics and has been studied in mammalian systems. Present research outlines the investigation of 1-DNJ and its role in plant species. 1-DNJ being a known competitive inhibitor of α-glucosidase, its role in starch hydrolysis during seed germination and leaf starch hydrolysis at night time is hypothesized. This study reveals that the seed germination and seedling vigour of mulberry, rice and wheat seeds are affected in the presence of 1-DNJ with highest inhibitions of germination noticed in mulberry seeds and leastinhibition in paddy seeds. However, starch hydrolysis at night in leaf is not affected, as 1-DNJ levels in leaf extract of mulberry are diurnally regulated. Studies on starch content and maltase enzyme (target of 1-DNJ) activity highlights that the starch content in DNJ or SA treated leaf gets reduced and maltase enzyme activity to be increased during night time similar to untreated control. Further, metabolites such as glucose, fructose and sucrose are increased in night in DNJ or SA treated leaves as in untreated leaves, in line with starch hydrolysis. Thus, the diurnal regulation of 1-DNJ content and its role in starch metabolism in mulberry is being reported for the first time. The similar study in contrasting genotypes would strengthen the present findings.ThesisItem Embargo COMPARATIVE ANALYSIS OF ROOT GROWTH AND THE BIOACTIVE CHEMICAL COMPONENTS IN FIELD AND AEROPONICALLY GROWN ASHWAGANDHA (Withania somnifera L.)(University of Agricultural Sciences GKVK, Bangalore, 2022-12-28) MADHURYA RAY; Mohan Raju, B.Ashwagandha, a medicinal crop produces withanolides as an important secondary metabolite has high medicinal value. Withanolides are predominantly found in roots and therefore, it is highly relevant to improve root biomass to derive more benefits from this crop. Aeroponic technology offers a good solution for maximizing root production. However, growing plants under aeroponic system requires suitable nutrients solution and spray scheduling as these two components are crop specific. Therefore, nutrients solution and spray scheduling were standardised for ashwagandha and accordingly, standard Hoagland’s solution with additional 50% N and K each with a spray scheduling of 1 minute on and 3 minutes off was found to be very effective. Following said protocol, ashwagandha plants were grown in aeroponic chambers. For comparison, plants were also grown on root study structure in the field. When the plants were of 120 days, desiccation stress was imposed in aeroponic chamber by reducing spray frequency to 1 minute on and 6 minutes off and withholding irrigation in field for 20 days to examine its effect on secondary metabolites production. At maturity, plants were harvested and biometric parameters and secondary metabolite content measured in both control and stress treatment of aeroponic and field grown plants. Results indicate that. field grown plants had thicker and sturdier roots with different root architecture compared to aeroponically grown plants where the roots were thinner and longer. Further, field grown plants had more secondary metabolites than aeroponically grown plants under control and stress condition although withanolides content remains more or less similarThesisItem Embargo COMPARATIVE OMICS APPROACH FOR IDENTIFYING CANDIDATE METABOLITES FOR DROUGHT TOLERANCE IN RICE(University of Agricultural Sciences GKVK, Bangalore, 2022-12-27) CHAITANYA, M. P.; Sheshshayee, M. S.Rice is traditionally cultivated in the semi-aquatic flooded condition, consuming 50% of freshwater. The diminishing water resources and prevalent climate change challenges demand to development of lesse water consuming cropping systems. Though closely related cereal, wheat requires substantially less water than rice without compromising on yield. A comparative study was carried out to investigate the underlying drought tolerance mechanisms between rice cultivars IR64 (lowland), Apo (aerobic) and wheat variety Weebill. Using the high throughput drought simulation phenotyping facility, precise moisture stress was imposed at the vegetative stage. Variability in the stress response was captured by performing untargeted metabolome analysis. Distinct accumulation patterns of the metabolites were observed under control and stress treatments, both within and between the species. Under the water deficit condition, polyamine, sphingosine-1-phosphate, anthranilate, flavonoid and flavone biosynthetic pathways were significantly upregulated. To validate the identified metabolites, 14 contrasting rice genotypes were selected which were previously reported to have acquired tolerance traits (ATT’s). The biochemical and physiological assays proved the consistency of ATT’s similar to previous studies. Further validation for key regulatory genes in the metabolic pathways was conducted through gene expression analysis. With final goal of enhancing drought tolerance mechanisms in rice, some promising rice genotypes genotypes which had fold change levels comparable to that of Weebill were screened, which can be utilized in future crop improvement studies.ThesisItem Embargo PHYSIOLOGICAL AND MOLECULAR CHARACTERIZATION OF Arabidopsis MUTANTS FOR COMBINED DROUGHT AND HEAT STRESS RESPONSE(2022-12-30) BHRUNDHA, K.; Dr. BHAUSAHEB TAMBATDrought and heat stress are the most frequently occurring environmental factors under field condition causing more severe crop loss than individual drought and heat stresses. Among the cereals, rice is more sensitive to combined drought and heat stress at the reproductive stage especially under semi-irrigated ecosystem. For the development of climate resilient crops, an empirical understanding of combined stress is required which can be achieved through the identification and characterization of genes specific to combined stress or shared between individual drought and heat stresses. Through meta-analysis of public transcriptome datasets, eighteen common genes shared between individual drought and heat stresses were identified in rice. To study the functional relevance of these genes, their orthologs were identified in Arabidopsis, a model plant, and their knockout mutants were procured. In this study, five mutants (dnaj_hsp, cch, hp1, lnk1, and duf506) were extensively characterized under combined drought and heat stress. Phenotyping and biochemical assays revealed that dnaj_hsp and cch are positive and negative regulators of combined stress, respectively. Furthermore, the genes DNAJ_HSP and CCH were selected for molecular analysis. The drought stress responsiveness of the genes DNAJ_HSP and CCH was confirmed by in silico expression analysis. Additionally, coexpression analysis showed potential association of DNAJ_HSP with the genes JMJ21 and NOI3 and CCH with the genes YSL2 and FSD1. The expression analysis by semi-quantitative and quantitative RT-PCR in wild-type and mutants under stress and the assays suggest the potential significance of DNAJ_HSP and CCH under combined drought and heat stress in Arabidopsis.ThesisItem Open Access ISOLATION AND EVALUATION OF ENDOPHYTIC FUNGI FROM POKKALI RICE CULTIVARS FOR THEIR ABILITY TO IMPART SALINITY STRESS TOLERANCE TO THEIR HOST PLANTS(UNIVERSITY OF AGRICULTURAL SCIENCES, BANGALORE, 2022-06-22) KOUSALYA, S.; Uma Shaanker, R.Endophytes (fungal or bacterial) are microorganisms that colonize the intercellular spaces of hosts and complete all or one part of their life cycle within the plant system without causing any damage and visual symptoms. These endo-symbionts have been reported to confer biotic and abiotic stress tolerance to their hosts and are readily isolated from hosts and cultured on artificial media. In this study, an attempt was made to examine endophytic fungal diversity of salt adapted rice cultivars from Pokkali and that from a salt sensitive rice variety, IR-64. The study examined the relative ability of endophytes from these contrasting rice cultivars in tolerating salinity stress. Finally, the study also examined the role of endophytes from salt adapted rice cultivars in imparting salinity stress tolerance to their hosts. A total of 62 isolates were obtained from salt adapted and salt sensitive rice cultivars. They were morphologically characterized into 11 operational taxonomic units (OTUs). Molecular characterization using ITS primers, identified them as Orbilia foliicola and Curvularia lunata from salt adapted Pokalli varieties and Cochliobolus miyabeanus from salt sensitive IR-64. Mycelial growth of Curvularia lunata was more in salt amended condition (150 mM) than in control. Isolates from salt adapted paddy genotypes were able to tolerate higher levels of salinity stress compared to isolates from salt sensitive paddy genotype. Bavistin-treated Pokkali seedlings were unable to withstand salinity stress because of loss of non-target beneficial fungal endophytes indicating that endophytes may have role in improving growth and development under stress in their host plants.
