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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 Open Access STUDIES ON MORPHOLOGICAL AND BIOCHEMICAL FACTORS IMPARTING RESISTANCE AGAINST AMERICAN PINWORM, Tuta absoluta (MEYRICK) (LEPIDOPTERA: GELECHIIDAE) AND THRIPS SPECIES IN TOMATO(UNIVERSITY OF AGRICULTURAL SCIENCES GKVK, BENGALURU, 2019-12-27) PRITHA GHOSH; JAGADISH, K. S.Investigations on morphological and biochemical factors imparting resistance against Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) and thrips species in tomato revealed that egg and larval load of T. absoluta were found to be significantly higher during summer 2018-19, followed by rabi 2017-18 and kharif 2018-19. Four thrips species were recorded namely Gynaikothrips uzeli Zimmermann, Scirtothrips dorsalis Hood, Thrips palmi Karny and Thrips hawaiiensis Morgan from the field screening. Pheromone trap catches of T. absoluta had significant negative correlation with rainfall (r = -0.35*) and relative humidity (r = -0.61*) and significant positive correlation with temperature (r =0.76*). Laboratory bioassays confirmed the resistances of wild accessions of tomato against T. absoluta and TOSPO vector, S. dorsalis by recording significantly lower egg load and higher larval mortality as compared to the susceptible check. Higher acylsugar content had a negative impact on T. absoluta larvae and resulted in reduced pupal weight. Dense glandular trichomes showed highly significant positive correlation (R2=0.94*) with acyl sugar content. Total glandular trichomes showed significant negative correlation with egg load (R2= 0.89*). Wild accessions showed contrasting differences in their green leaf volatile profile as compared to susceptible genotypes. Among biochemical parameters, acyl sugar, tannin, phenol, monoterpene and sesquiterpene contents were found at significantly higher quantity in resistant wild accessions as compared to susceptible genotype.ThesisItem Open Access INVESTIGATIONS ON BEHAVIOUR AND CHEMICAL ECOLOGY OF MELON FLY, Zeugodacus cucurbitae (Coquillett) (DIPTERA: TEPHRITIDAE)(UNIVERSITY OF AGRICULTURAL SCIENCES GKVK, BENGALURU, 2019-12-27) SUBHASH, S.; CHAKRAVARTHY, A. K.The volatiles of host plant stimulate a wide range of behavioural response in the insects that are associated with them. The melon fruit fly, Zeugodacus cucurbitae (Diptera: Tephritidae) being oligophagous in nature deals with widely cultivated cucurbitaceous crops. Nevertheless, their mechanism of finding preferred host plant as well as conspecific mate and the molecular basis of olfaction is unknown. In this study, we show the ovipositional preference of melon flies and the behaviour eliciting host chemical cues. We studied the response of melon flies to immature and mature stage fruits of four different cucurbits. The gravid female flies preferred the mature ridge gourd fruits over other cucurbit hosts. On further investigation analytically the eight specific molecules which the melon fly uses in locating their host, viz., 1-Octen-3-ol, α-Pinene, p- Cymene, p-Ethyl-benzaldehyde, Methyl salicylate, p-Cymen-7-ol, Benzoic acid, 4-ethyl methyl ester and Heptacosane were identified. On molecular front, we developed the transcript assembly of melon flies antennae using the Illumina Next Seq 500 system. A total of 21,504 unigenes along with 137 chemosensory genes responsible for the odour detection mechanism in flies were covered. The homology model of 23 select odour binding proteins was built and In-silico docking analysis was performed against the eight host identified chemical cues. Docking results disclosed that 1-Octen-3-ol had very interactive energy with the selective odour binding proteins (5, 7) than any other ligands. Our results suggest that the flies deploy unique proteins to determine the specific molecules present in their preferred host ecospace. Further, we established that the synthetic blend of behavioural active chemical cues is equally attractive to gravid melon flies when compared to natural fruit sample. This study opens up huge arenas to evaluate the identified chemical cues in the field ecosystem for its potential to trap female melon flies.ThesisItem Open Access MOLECULAR DETECTION, MECHANISM OF RESISTANCE AND MANAGEMENT OF LEAFHOPPERS IN PHYTOPLASMA ASSOCIATED SESAME PHYLLODY(UNIVERSITY OF AGRICULTURAL SCIENCES GKVK, BENGALURU, 2019-12-12) PALLAVI, D.; VIJAYKUMAR, L.The investigation on molecular detection, mechanism of resistance and management of leafhoppers in phytoplasma associated sesame phyllody was undertaken at college of Agriculture, V. C. Farm, Mandya and Department of Entomology, UAS, GKVK, Bangalore from 2017 to 2019. The peak leafhopper population and incidence of phyllody were noticed during second fortnight of April in Summer and first fortnight of October in Kharif during 2017 and 2018, respectively.The phytoplasma was detected from infested sesame plants and leafhoppers through molecular techniques using different primers viz., P1/P7, SECA1/A2,Tuf and obtained 1.8kb, 840bp and 490 bp product size, respectively. The genomic DNA of symptomatic plants and leafhoppers were found to be associated with phytoplasma belongs to 16SrI ‘Candidatus phytoplasma asteris’group. The detection of phytoplasma also confirmed using loop mediated amplification assay. The field evaluation of twenty seven sesame genotypes against leafhoppers and phyllody resulted in identifying four highly resistant genotypes. Among the biochemical constituents studied for resistance and susceptibility, the total phenols showed significant negative association with infestation, while, total sugars, reducing sugars, total free amino acids and crude proteins indicated significant positive relationship with incidence of phyllody. The studies on impact of feeding by leafhoppers on plant morphological and biological attributes in different genotypes under controlled and open field conditions revealed higher incidence, enzymes and nutrients levels in open field than controlled condition. Among nine insecticides evaluated against leafhoppers and phyllody, seed treatment with imidacloprid 48FS @ 5ml/kg with foliar spray of thiamethoxam 25WG @ 0.3g/L was found effective in reducing incidence along with higher seed yield, net returns and C: B ratio compared to other treatments.ThesisItem Open Access POPULATION ECOLOGY AND REPRODUCTIVE BIOLOGY OF THE COFFEE WHITE STEM BORER, Xylotrechus quadripes CHEVROLAT (COLEOPTERA: CERAMBYCIDAE)(UNIVERSITY OF AGRICULTURAL SCIENCES, GKVK BENGALURU, 2019-10-10) FAKEERAPPA R. PATTAN; BELAVADI, V. V.The present investigation on the population ecology and reproductive biology of Coffee White Stem Borer (CWSB), Xylotrechus quadripes Chevrolat (Coleoptera: Cerambycidae) has confirmed that there is only one brood out of the same clutch of eggs with typically one age structured population. Earlier it was hypothesized that there were two broods out of the same clutch of eggs. This study also confirmed that, there were two flight periods (summer and winter) every year. The overall sex ratio of CWSB was female biased. Mating behaviour, fecundity and longevity of female beetles of CWSB was investigated under laboratory conditions. Pairs of male and female beetles maintained in cages showed that the female beetles approached the males and mated multiply to lay eggs. In a single pairing event, the female copulated multiply with the mounted male (on an average 5.07 ± 1.49 times) and laid a batch of eggs. Following an egg laying bout, the female mated again with the male and oviposited. This intermittent mating and egg laying continued throughout the lifespan of the female. To test the hypothesis that, females of CWSB mated multiply to enhance fecundity, a series of experiments were conducted. Females that mated intermittently laid a greater number of eggs (140.72 ± 42.50) than a singly mated female (31.3 ± 6.08). On an average a female (intermittently) mated 12.2 times and was able to lay 140.72 ± 42.50 eggs. The maximum number of eggs per clutch was observed in the fourth clutch (19.3 ± 6.61). 85.71% of eggs were laid within six clutches and later the number of eggs per clutch decreased as did the frequency of mating. However, females which mated multiply had significantly reduced lifespan than virgin females.ThesisItem Open Access ISOLATION, IDENTIFICATION AND FIELD EVALUATION OF PHEROMONE COMPOUNDS OF FRUIT PIERCING MOTH WITH SPECIAL REFERENCE TO Eudocima materna LINNAEUS (LEPIDOPTERA: EREBIDAE)(UNIVERSITY OF AGRICULTURAL SCIENCES, GKVK BENGALURU, 2019-09-17) MALLIKARJUN; THIPPAIAH, M.The pomegranate fruit-piercing moth, Eudocima materna is a pest of ripening fruits over much of the tropical and subtropical Southeast Asia, Australia and Western Pacific Islands. Moths remain active from August to October in India and attacks ripening fruits of pomegranate. Studies on increasing field attractancy using sex pheromones have not been undertaken. The current study was initiated to explore the utility of sex pheromone for its management. The adult emergence of E. materna was observed throughout the day and not significantly influenced by sex, but by the time of the day. An age-dependent pattern of calling and mating was observed. The maximum percentage of calling and mating moths were recorded at 5th h of scotophase. Blend combinations involving pheromone components with fruit volatiles viz., 2-Ethyl Hexanol and 3-Ethyl Benzaldehyde elicited a higher antennal response (EAG) and behavioural responses (Wind tunnel). Fero-T Traps were found better for trapping adult moths. The field evaluation of 10, 20 and 40μl doses for three superior blends viz., blends-B, Q and N separately revealed that doses 20 and 40μl were found on par. Whereas, dose 20μl was found significant compared to other doses in both the blends-Q and N. Comparative field trials of optimum doses of best-performing blends indicated that 20μl dose of blend-B significantly trapped more male moths at Kegaon and Hiraj, Solapur, Maharashtara.ThesisItem Open Access ROLE OF TERMITES IN DRY LAND ECOSYSTEM AND THEIR MANAGEMENT(UNIVERSITY OF AGRICULTURAL SCIENCES, GKVK BENGALURU, 2019-05-24) AVINASH, T. G.; KUMAR, N. G.Present investigation was carried out at the University of Agricultural Sciences, GKVK, Bengaluru during 2016-18. Maximum termite damage to bait was noticed in maize followed by sunflower and finger millet ecosystem. Influence of abiotic factors on termite activity was 67.60, 49.30 and 26.20 per cent in maize, sunflower and finger millet ecosystem, respectively. Total rainfall, in situ soil moisture and minimum soil temperature exhibited significant positive impact on the termites activity. Odontotermes obesus constructs conical shaped mound with one or more hollow turrets. The height and circumference of the mound varied based on the age of the colony. Inner mound wall possessed small pin holes distributed more on the top portion. The royal chamber was flat based hard earthen structure located with a mean depth of 27±5.03 cm. Mound height found significant positive correlation with depth, length, breadth and inner height of the royal chamber and length of the queen. Different shaped unilocular fungal combs were distributed 20-40 cm above and below soil surface. Eggs, nymphs, workers, soldiers and alate nymphs were present in the fungal combs. A small supplementary royal chamber with king and queen was also present. Composition of sand, silt and clay content varied in different portion of the mound, royal chamber and earthen sheetings with dominance of clay content. Earthen sheeting soil was slightly acidic with 0.51, 0.01 and 0.01 % of OC, N and K content, respectively. The combination of surrounding soil + mound soil + FYM (75: 10 : 15%) medium supported maximum plant height, pod production and higher soybean yield. Bifenthrin @ 0.05%, chlorpyriphos @ 0.1 % and clothianidin @ 0.075% treated soil protected the baits up to 20 months. Bifenthrin 2.5% EC was found more toxic with the LC50 of 4.35 and 4.93 ppm against O. obesus and O. horni, respectively.ThesisItem Open Access POPULATION DYNAMICS, INSECTICIDE RESISTANCE/SUSCEPTIBILITY AND CHEMICAL CONTROL OF THRIPS, SCIRTOTHRIPS DORSALIS HOOD (THYSANOPTERA: THRIPIDAE) INFESTING CHILLI(UNIVERSITY OF AGRICULTURAL SCIENCES GKVK, BENGALURU, 2018-11-14) MANJUNATHA, K. L.; Srinivasa, N.Investigations were carried out on population dynamics, insecticide resistance/susceptibility and chemical control of chilli thrips, Scirtothrips dorsalis at three locations, Kotagal (Chintamani), IIHR & GKVK in Bengaluru during 2015-17. The peak activity of thrips on kharif crops across three locations was more apparent during October-November period when crop age was 90-120/150 days and on rabi-summer crops during February-March on 100-120 days old crop. Influence of abiotic (maximum temperature, bright sunshine hours, evaporation) and biotic (natural enemies) factors significantly influenced the buildup of thrips, while minimum temperature, RH, rainfall and wind speed adversely affected thrips activity. Step-wise regression analysis revealed more significant positive influence of maximum temperature, minimum temperature, natural enemies, evaporation and afternoon relative humidity, while rainfall influenced thrips activity negatively. At Kotagal, application of spinosad resulted in maximum reduction of thrips (91%) after 7 days followed by acephate (72%), dimethoate (69%), imidacloprid (61%), fipronil (61%), diafenthiuron (60%), clothianidin (55%) and thiamethoxam (55%). Spinosad application continued to record significant decline in thrips population up to 10 days, which resulted in higher green fruit yield of 9.02 tonnes/acre. At IIHR also, within one week after application, spinosad caused >87% reduction in thrips population and fruit yield obtained was also highest (13 tonnes/acre). Among the insecticides assayed in laboratory, spinosad was found more toxic to thrips with the lower LC50 values ranging from 44.28 to 46.40 ppm. Acephate was least toxic with higher LC50 values between 572.80 and 602.80 ppm. Order of toxicity of other insecticides was; imidacloprid (47.66-53.94ppm), fipronil (51.97-62.40ppm), clothianidin (95.72-101.90ppm) and diafenthiuron (230.56- 325.65ppm). Based on LC50 and LC90 values, the toxicity of these insecticides to populations of thrips across the three study locations was observed to be similar (1.02-1.41 and 1.03-1.37, respectively)ThesisItem Open Access MOLECULAR DIVERSITY OF Conogethes spp. GUENÈE, (LEPIDOPTERA: CRAMBIDAE) INFESTING ON SELECT HOST IN INDIAN SUB-CONTINENT(UNIVERSITY OF AGRICULTURAL SCIENCES, GKVK BENGALURU, 2018-12-21) VASUDEV KAMMAR; Chakravarthy, A. K.Moths of Conogethes spp. are economically important polyphagous pests infesting >120 wild and cultivated crops worldwide. Study was undertaken to unravel the difference between Conogethes spp. populations feeding on castor and cardamom. Based on the morphological and molecular studies Conogethes feeding on cardamom was diagnosed as C. sahyadriensis and on castor as C. punctiferalis. Results revealed nucleotide variations occurred between C. punctiferalis and C. sahyadriensis to an extent of 5.32% indicating high genetic divergence. The pairwise genetic distance analysis between the Conogethes species varied from 0.000 to 0.043. Within a Conogethes species complex, the two Conogethes species (C. punctiferalis and C. sahyadriensis) were formed in to two distinct clades and results revealed divergence of C. punctiferalis and C. sahyadriensis apparently began around 0.03 mya. The haplotypes network analysis substantiated the results by showing distinct haplotypes. We opined that speciation of C. punctiferalis and C. sahyadriensis seems to have independent lineages and diversification may be host-related as C. punctiferalis is a polyphagous species while C. sahyadriensis is oligophagous preferring Zingiberaceae crop plants. Under the lock-and key hypothesis, allometric relationships between somatic and genitalic traits of both sexes of each species and observed that, male genital and associated structures were prone to changes more than the female genitalia associated structures. Further we have identified species-specific markers based on COI gene for Conogethes species for rapid identification of these pests in India. Developed markers can be used to identify Conogethes populations which are indistinguishable and cryptic in nature. In this study clearly established that two species of Conogethes remained skewed for a long time in India and many other neighboring countries despite several studies on different aspects of the two Conogethes populations.ThesisItem Open Access BEE POLLEN AS INDICATOR OF FLORAL DIVERSITY: A STUDY USING SOLITARY AND SOCIAL BEES(UNIVERSITY OF AGRICULTURAL SCIENCES GKVK, BENGALURU, 2018-10-01) PRADEEPA, S. D.; BELAVADI, V. V.A study involving pollen collected by solitary and social bees to assess floral diversity was carried out during 2015-2017 at GKVK. Flowering phenology and rewards offered (Nectar/pollen) were recorded for a total of 158 plant species in the study area. Reference pollen slides were prepared for all species and microphotographs were made. Pollen sampled from nests of Apis cerana and Megachile spp. were identified using reference pollen slides which represented 77 species. Floral preference by social and solitary bees differed significantly. Apis cerana being polylectic, foraged on a diverse flora and collected pollen from 67 species representing 29 families among these Cocos nucifera, Eucalyptus and Peltophorum were the most abundant species and their frequency ranged between 30 to 70 per cent. Whereas, megachilids collected pollen from 21species of only eight families, Fabaceae (>95 %) was the dominant one contain Crotalaria juncea, Peltophorum pterocarpum, Cajanus cajan, Dolichos lablab and Millettia pinnata were the most dominant species preferred by megachilids. There was an overlap of only eight species between Apis and Megachile species. There was a negative relation (r = -0.44) with floral diversity in the field and pollen grain diversity in the bee nests. Which may be because of preference by bees for pollen collection from certain species of flowering plants? To test this hypothesis, plant species visited by bees was filtered and correlated with the pollen flora in the nests. Such an analyses showed a positive linear relationship (r = 0.37) between available flora and pollen diversity in the bee nests. Further, seasonality in pollen collection showed that wet season had strong relation (r = 0.63) between nest and corresponding field flora followed by summer (r = 0.58) and winter (r = 0.45) seasons.