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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 IDENTIFYING THE MOLECULAR MECHANISMS OF BACTERIAL EFFECTOR PROTEINS FROM Xanthomonas oryzae pv. oryzae CAUSING LEAF BLIGHT DISEASE IN RICE AND USE OF SMALL MOLECULES IN DISEASE RESISTANCE(University of Agricultural Sciences, Bangalore, 2023-05-05) SWATHI, S. PATIL; M. K. PrasannakumarRice (Oryza sativa L.) is the most important staple commodity, providing food for nearly half the global population. The bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most destructive diseases afflicting rice fields. The morphological, biochemical and pathogenicity characteristics of ten Xoo isolates from various rice-growing regions in India were used to differentiate them. The pathogenicity assay determined that all isolates were virulent on the susceptible variety TN-1, with the KA isolate producing significantly more lesion length, in planta bacterial count, xanthomonadin, and exopolysaccharide. Through dual transcriptome analysis of contrasting rice cultivars (TN-1 and RP-Bio226), disease resistance genes such as ARK1AS, mla1, RPM1, RPS2 and RPP-13 protein 1 were found to be upregulated in RP-Bio226 in response to Xoo infection. In the susceptible variety, the production of the susceptibility gene OsSWEET11 was upregulated, whereas it was downregulated in the resistant cultivar RP-Bio226. Many type 3 secretion system proteins, including PthXo1, XopN, XopW, HrpB2, SctJ, and SctN were identified in Xoo infecting the susceptible variety, but none in the resistant variety. RP-Bio226 produced higher levels of hydrogen peroxide and superoxide anion than the susceptible variety TN-1. Using plants expressing OsSWEET11- gRNA, the OsSWEET11 gene was characterised using the CRISPR Cas9 gene editing technology. Gene editing was confirmed in the transgenic plant S21 with change in amino acid from isoleucine to leucine at position 263 and leucine to isoleucine at position 266. S21 also displayed a resistant reaction to Xoo. In addition, a novel small molecule 6-[(3- oxido-2,1,3-benzoxadiazol-3-ium-5-yl)oxy]2,1,3-benzoxadiazol-1-ium-1-olate was identified through a chemical genomics approach, targeting the effector protein PthXo1 to confer resistance against Xoo in the TN-1 variety. The plants sprayed with the small molecule immediately following Xoo inoculation exhibited a significant decrease in lesion length and in planta bacterial count compared to the control.ThesisItem Embargo IDENTIFICATION AND BIO-MANAGEMENT OF ROOT-KNOT NEMATODE (Meloidogyne enterolobii) IN GUAVA (Psidium guajava L.)(University of Agricultural Sciences, Bangalore, 2023-04-04) M. VARSHA; Kavitha, T. R.Meloidogyne enterolobii is an emerging and most serious pest of guava in Southern India. Biological control method is an effective strategy in management of root knot nematodes ensuring soil fertility and environmental health. The goal of our study is to evaluate the distribution and severity of M. enterolobii on guava in Southern Karnataka and find an effective combination of bioagents for root knot nematode (RKN) management. Survey conducted in a total of 10 guava orchards from four districts of Southern Karnataka, the major guava cultivating areas revealed the incidence of M. enterolobii in all the places. Visual evaluation of infested roots by galling index (RKI) recorded the highest distribution and severity of RKN in Ramanagara district (RKI-4.00) followed by Bengaluru (RKI-3.00) and Bengaluru rural (RKI-2.00). The identity of the nematode isolates was confirmed by a combination of morphological and molecular methods. The cuticular modifications at the posterior region of the female nematode were consistent with the perineal patterns of M. enterolobii. Further, molecular characterization of isolate GBN-1, by sequencing of 18SrRNA region confirmed the nematode as M. enterolobii. Among various combination of bioagents tested under field conditions revealed that the treatment T5 [Trichoderma asperellum+Bacillus subtilis+neemcake+African Marigold (30mL+30mL+100g/plant)] imposed at monthly interval was effective in reducing the nematode population in soil (746.67/200 cc) and roots (149.33/5g root), maximum reduction of galls (13.67/5g root), egg masses (17.67/5g root) and over control (1248.11/200 cc, 284.33/5g root, 36.00/5g root, 41.33/5g root) of the nematodes respectively.ThesisItem Embargo SUSTAINABLE PRACTICES IN RELATION TO GROWTH, ANTICHILCV AND ANTI-WHITEFLY ACTIVITIES IN RESPONSE TO DEFENCE INDUCING BIO-MOLECULES IN CHILLI(University of Agricultural Sciences, Bangalore, 2023-02-15) ABHISHEK H J; Manjunath, B.Chilli is an important vegetable cum spice crop, known as wonder spice. Chilli leaf curl virus (ChiLCV) is a major threat for the production and productivity and it is transmitted by whitefly. In order to manage the whiteflies farmers indiscriminately use of huge amount of pesticide, resulting in resurgence of the pests, phytotoxicity, human health hazards, destruction of beneficial microorganisms and environmental pollution. Induction of biochemical defence and eco-friendly management through bio-molecules is a new trend. Among different tested sea weed molecules and plant extract in both laboratory and glass house condition, Neem soap (8gm/L) was found effective. In lab condition maximum mean mortality of whiteflies was recorded in agar plate method (60 %) in cotton leaves. While, least preference (10 whiteflies) and fecundity (35 eggs) was observed in glass house condition which was tested in cotton plants. The LBD12 (1.0ml/L) and LBD-14 (1.0ml/L) bio-molecule treated chilli plants showed least disease severity in both pre-inoculation (38.89 % and 42.22 %) and post-inoculation (22.22 % and 23.44 %) which were significantly enhanced defence related enzymes such as POX, Catalase, PPO, SOD, PAL and phenol in both pre-inoculation and post-inoculated condition. Eight integrated modules had been developed and evaluated for management of ChiLCV and whitefly activity in three different farmer’s field. Among them module-1 and module-2 exhibited least whitefly activity and recorded least disease incidence and severity compared to other modules. Maximum yield was observed in both the modules (26.87 t/ha and 24.04 t/ha) with the B:C ratio of (6.72:1 and 6.01:1) as compared to other module.ThesisItem Open Access PROSPECTING ENDOPHYTES ASSOCIATED WITH Solanum lycopersicum L. FOR THE POTENTIAL ACTIVITY AGAINST TOMATO LEAF CURL VIRUS AND ITS VECTOR Bemisia tabaci(University of Agricultural Sciences, Bangalore, 2023-02-14) AVINASH PHULEKAR; N. NAGARAJUIn recent years, endophytes have become increasingly important due to the harmful effects of chemical pesticides. An attempt to exploit endophytes as a potential biocontrol agents against tomato leaf curl virus and its vector whitefly, Bemisia tabaci was made in the present study. A total of 26 endophytes were isolated from plant tissues of tomato, of which 18 were fungi and 8 were bacteria. The endophytes viz., RF4, SF7 and RB3 showed antivector activity against eggs and adults of B. tabaci with decreased egg hatchability respectively by 69.40, 67.56 and 71.10 per cent at 10 days after treatment. However maximum mortality of adult whiteflies was observed at 3 DAT (76.67, 73.33 and 70.00% respectively). The endophytes RF4, SF7 and RB3 were found efficient in production of lytic enzymes. The chitinase activity was observed in RF4 and SF7, while protease and esterase activity was evident in SF7 and RB3. Among the different treatments, T4 [endophyte (seed treatment, seedling dip and spray) followed by virus inoculation] showed the maximum plant height (RF4-95.00, SF7-92.66 and RB3-94.33 cm), T5 [endophyte (seed treatment and spray) followed by virus inoculation] displayed maximum number of branches (RF4-3.66, SF7-3.66 and RB3-4.00) and lowest disease severity was displayed by T4 (RF4-8.33, SF7-16.66 and RB3-25.00%) at 45 DAT. Molecular characterization of endophytic fungi revealed RF4 as Fusarium oxysporum f. sp. lentis and SF7 as Fusarium sp. whereas endophytic bacteria (RB3) as Acinetobacter sp. Finally, RF4 (Fusarium oxysporum f. sp. lentis) showed its potential anti-vector and anti-viral activities.ThesisItem Open Access DECIPHERING SUPPRESSORS OF PLANT CELL DEATH (SPD) EFFECTORS DURING MAGNAPORTHE ORYZAE: RICE INTERACTION AND DEVELOPMENT OF BLAST DISEASE FORECASTING MODEL(University of Agricultural Sciences, Bangalore, 2023-02-13) JAYASHREE A; A. NAGARAJARice blast disease caused by Magnaporthe oryzae (Hebert) Barr is one of the leading constraints to global rice production and a serious threat to food security. The present study aims to decipher the role of suppressors of plant cell death (SPD) effectors during host pathogen interaction and develop a weather driven forecasting model for rice blast disease by employing machine learning algorithms and understanding the rice defence response to high temperature upon challenge inoculation with the pathogen. In-silico identification, modelling and functional analysis of SPD effectors in M. oryzae revealed that eleven SPD effectors under study were predicted to fulfil the criteria to fit in the definition of candidate secreted effector proteins. The SPD effectors were composed of a signal peptide, ≥ 3 per cent of cysteine residues, no transmembrane domains, ≤ 250 amino acids and a low molecular weight of below 50 KDa. The majority of homologs, orthologs and paralogs identified belonged to ascomycetes. The SPD effector MG01_03488 was expressed using a pET32a (+) expression vector and the protein was purified using Ni- NTA affinity chromatography. Priming rice plants with prokaryotic expression product of MG01_03488 resulted in the suppression of reactive oxygen species and other defence related enzymes, consequently facilitating pathogen virulence. Of the six machine learning techniques employed in rice blast prediction, the artificial neural network was more efficient, with 98.84 per cent accuracy. Temperature and relative humidity were significant weather contributors in predicting rice blast through machine learning approaches. Magnaporthe oryzae inoculation and induced high temperature stress increased rice blast disease severity and resulted in a substantial reduction in the photosynthetic pigments, carotenoids and anthocyanin content and increased membrane injury index, malondialdehyde, reactive oxygen species, lipoxygenase activity, antioxidant activities and higher relative expression of Pi2 and Pi54 resistance genes as compared to non-stress rice seedlings.ThesisItem Embargo VIROME PROFILING IN GLADIOLUS AND TUBEROSE CROPS USING NEXT GENERATION SEQUENCING (NGS)(University of Agricultural Sciences, Bangalore, 2023-03-02) YOGESH BASTWADE; VENKATARAVANAPPA, V.Viral diseases becoming major constraints for production of gladiolus and tuberose resulting in huge losses to growers in our country. Diagnosis of viruses infecting gladiolus and tuberose is very crucial to design management strategies. Next-generation sequencing (NGS) based virome profiling, an advanced sequencing technology has become popular method for the accurate detection of viruses present in the samples. A total 20 different virus-infected leaf samples from gladiolus and tuberose showing mottling, mosaic and yellowing symptoms were collected during the year 2021–22. Total RNA was isolated from all collected samples and used as an input for mRNAome sequencing. Raw data obtained were subjected to De-novo assembly. Further,individual contigs were subjected to standalone MEGABLAST against viral reference genomes available in NCBI database. Mapping of contigs against reference viral genome through BioEdit, Clustal X was carried out to reconstruct the complete/near-complete genome viruses. However, bean yellow mosaic virus (BYMV) and ornithogalum mosaic virus (OrMV) in gladiolus whereas, tuberose mild mosaic virus (TuMMV) and tuberose mild mottle virus (TuMMoV) were identified in tuberose, however, CMV infection was found in both gladiolus and tuberose. Further, recombination analysis using RDP5 indicated presence of recombination only in BYMV. Molecular tools i.e., RT-PCR and RT-LAMP were optimized for rapid detection of identified viruses. Infection of CMV in tuberose is the first report from our study in IndiaThesisItem Open Access ETIOLOGY AND DIVERSITY OF SHEATH ROT FUNGAL PATHOGENS OF RICE(University of Agricultural Sciences, Bangalore, 2023-02-11) NIDHI AKKIN; B. S. CHETHANASheath rot disease of paddy caused by Sarocladium oryzae is one of the emerging diseases in the world. Study was carried out to understand etiology, characterization and seed transmission of sheath rot associated fungal pathogens, and to elucidate the diversity of fungal sheath rot pathogens in rice. Etiology studies and pathogencity of 22 isolates collected from Karnataka revealed that Sarocladium oryzae and Fusarium spp. are the causal organisms for sheath rot disease. Morphological and cultural haracterisation was carried out for all the isolates. Isolate SHTNGO-2 showed lowest growth rate of 0.30 mm/day, whereas, highest by SHMV1W having 8.25 mm/day. Virulence test of inoculation of pathogens, recorded largest lesion length of 3.3 cm in SHYDO-1 (Sarocladium oryzae), while, smallest lesion length of 0.4 cm recorded in SHSRG1W (Fusarium spp). Molecular characterization using ITS1/4 identified isolates to be Sarocladium oryzae. Fusarium oxysporum, Fusarium fujikuroi, Fusarium equiseti, and Fusarium proliferatum. Based on cultural, morphological characteristics and pathogenicity, 13 isolates were identified as Fusarium spp., while, 9 were identified as Sarocladium. Interaction studies of combined inoculation of Sarocladium oryzae and Fusarium proliferatum recorded larger lesion length of 3.1 cm, as compared to their individual inoculations. Jyothi seeds infected with sheath rot showed decreased germination. S. oryzae was found to be internally seed borne, while, Fusarium internally and externally seed borne. Phylogenetic tree showed less diversity among Sarocladium oryzae isolates and higher among Fusarium spp. Isolates.ThesisItem Embargo EPIDEMIOLOGY AND MANAGEMENT OF PHYTOPHTHORA LEAF BLIGHT AND FRUIT ROT IN SWEET PEPPER (Capsicum annuum L.)(2022-12-27) SANDEEP KUMAR G. M.; S. SRIRAMEpidemiology and management aspects of Phytophthora blight (Phytophthora capsici L.), an emerging disease of sweet pepper in India were investigated. Rainfall and relative humidity were identified as the significant parameters triggering the epidemic. The pathogen had fitness in temperature range of 10-34 °C, with optimum being 22 °C-28 °C. Relative humidity above 80% was conducive for leaf blight and fruit rot development. Soil moisture above 75% water holding capacity and saturation for 24 h aggravated root rot development. The pathogen can survive for 90 days in soil. Slender amaranth, black nightshade and spurge weeds were found as alternative hosts while cereals were non-hosts. Solanaceous, cucurbitaceous and leguminous vegetables varied in susceptibility. Based on CLIMEX simulation, Western Ghats and adjoining plains in Karnataka and Kerala, Western and Eastern Himalayan regions, hills in Orissa and Andaman and Nicobar islands were found highly favourable for P. capsici establishment under current and climate change (+2 °C) scenario. Integrated management schedule was developed with interventions viz., i) Seed treatment with Trichoderma harzianum Th-2 + Bacillus subtilis BS-2 at 10g/kg seed ii) Application of neem cake and farmyard manure enriched with bioagents to planting bed @1kg/100 kg iii) Raised bed planting (90-100 cm wide and 15-22 cm height) with silver-black reflective mulch film (30-100 μ) iv) Irrigation regulation and soil drainage management v) Weeding and sanitation vi) Protective foliar sprays of chlorothalonil 75% WP (2g/L) or mancozeb 75% WP (2g/L) in rotation at 15 day interval up to 40th standard meteorological week under Bengaluru conditions. Also, need based curative sprays and drenching with dimethomorph 50% WP (1g/L) + chlorothalonil 75% WP (2g/L), in rotation with dimethomorph 50% WP (1g/L) + mancozeb 75% WP (2g/L) were found effective. Highest B: C ratio ofThesisItem Open Access STUDIES ON GREY BLIGHT OF COCONUT CAUSED BY Pestalotiopsis palmarum (COOKE) STEYAERT(University of Agricultural Sciences, Bangalore, 2023-01-31) YATISH KUMAR, M.; Y. M. SOMASEKHARAGrey blight of coconut caused by Pestalotiopsis palmarum is one of the emerging disease in the southern Karnataka causing considerable yield loss. Disease symptoms characterized by greyish centre with dark brown margins. P. palmarum produces five celled conidia with three middle cells of brown colour, hyaline at basal and apical end with one to three setulae. The Koch’s postulate was proved by pin prick method. The pathogen was further confirmed as P. palmarum by molecular characterization by using ITS1 and ITS4 primers. The cultural and physiological studies recorded the highest colony growth on potato dextrose agar medium ( 90 mm) and the colony colour varied from greyish white to white with completely serrated to smooth margin, while the temperature 25oC and pH 6.0 were found to be the best for the growth of the pathogen. Among the different fungicides, bioagents and botanicals tested under laboratory conditions, the mean mycelial inhibition was highest among the fungicides such as ziram (1000 ppm), carbendazim and thiophonate methyl (500 ppm), trifloxystrobin 25 per cent + tebuoconazole 50 per cent (1000 ppm). Among fungal and bacterial bioagents, highest mycelial inhibition was found in Tricoderma viride-2 (Tv-2) of 71.30 per cent and Bacillus subtilis (Bs-O) with 52.22 per cent while among botanicals, turmeric extracts (20 %) were found most effective against the growth of the pathogen.
