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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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Subject: Entomology × Author: DIVIJA, S. D. × End date: 2022 × Type: Thesis × Thesis Type: Ph.D ×
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    Functional ecology and odour perception strategies of pollinators in onion, Allium cepa L.
    (University of Agricultural Sciences, Bangalore, 2022-09-28) DIVIJA, S. D.; Kamala Jayanthi, P. D.
    Onion, Allium cepa L. totally depend on pollinators for cross pollination as self-pollination is absent due to protandry. In insect-pollinated crop, the presence of flower is advertised by visual and olfactory cues. Currently, in A. cepa, there is no information on floral VOCs emissions vis-à-vis pollinator response. Keeping in view the above research gaps the present experiment was conducted during 2019-2021 at ICAR- IIHR, Bengaluru, India. A total of fifty-nine floral visitors corresponded to Hymenoptera, Diptera, Lepidoptera, Coleoptera and Hemiptera were documented from onion. Anthophilous insects majorly visited A. cepa flowers to collect nectar (81.59%). Gas Chromatography coupled to Mass Spectrometry study revealed the temporal variation in the onion floral volatile emissions across the different time periods of a day viz., morning (0800-1100 hrs), afternoon (1100-1400 hrs) and evening (1400-1700 hrs). Electroantennogram (EAG) studies revealed that bees (A. cerana, A. florea, A. dorsata and T. iridipennis) significantly get attracted towards morning and afternoon volatile emissions of onion flowers. GCEAD studies revealed that floral visitors don’t cue on all floral volatiles, but only a few compounds in the floral bouquet to locate flowers. Onion plants under eCO2 had a positive influence on nectar, pollen and quantity of scent emission. Even with changed volatile profiles under eCO2 condition, the bees tend to respond in a similar way. Electroantennogram (EAG) studies with EAD active synthetic chemicals revealed that floral visitors not only rely on the most common compounds to forage, but as well may learn about other compounds specific to a flower to increase their foraging efficiency. This study will further strengthen our understanding in chemical ecology covering question of info chemicals involved in plant-pollinators interaction. This study serves as a pilot study for the future chemo-behavioral studies in onion pollinators where such information is very limited in the Indian context.