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oai:www.ideals.illinois.edu:2142/19287 2023-07-10 col_2142_5131 col_2142_14798 com_2142_5130 com_2142_686 com_2142_397

Spomer, L. Art Al-Hemaid, Abdalrahman 2011-05-07T12:02:50Z 2011-05-07T12:02:50Z 10000-01-01 1995 Plant water deficit is the major factor limiting global crop productivity. Yield loss caused by water stress is estimated to exceed total loss from all other causes. Moreover, availability of agricultural water is declining worldwide because of increasing demand and decreasing quality. Consequently, knowledge of plant water requirement is mandatory for increasing water use efficiency and reducing ground water pollution. This study intended to determine Coleus x hybridus Voss. 'Goldbound' water requirement based on physiological responses most directly related to yield--expansion, stomatal conductance, net photosynthesis, dark respiration, and survival(injury). Fully-expanded, mature leaves proved the most representative and consistent indicators of whole plant water status as measured with a pressure chamber and vapor pressure osmometer. The most consistent time for water status measurement was at night or under other low transpiration conditions. Coleus survived dehydration up to 6 days with no perceptible injury, and 46 days based on ability to resume growth. Leaf expansion proved most sensitive to dehydration and even ceased before wilting could be perceived. Stomatal conductance and subsequent reduced intercellular CO$\sb2$ level was decreased next followed by net photosynthesis, which ceased at a water potential of $-$0.72 MPa. Although reduced, dark respiration never stopped throughout the water deprivation period. Leaf abscission began at very low water potential with all mature leaves eventually lost at $-$1.05 MPa. Coleus appeared to develop morphological and physiological resistance to subsequent dehydration when subjected to water deficits less than or equal to about $-$0.65 MPa. Made available in DSpace on 2011-05-07T12:02:50Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9543511.pdf: 5509628 bytes, checksum: 23be6ee0f9732c3a17e08ee2eaa4a1bc (MD5) Previous issue date: 1995 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:35:55Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:14:21-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission ETDs are only available to UIUC Users without author permission U of I Only AAI9543511 (UMI)AAI9543511 http://hdl.handle.net/2142/19287 eng Copyright 1995 Al-Hemaid, Abdalrahman Biology, Plant Physiology Characterization of Coleus x hybridus Voss. 'Goldbound' water requirements text Crop Sciences Horticulture University of Illinois at Urbana-Champaign Dissertation Ph.D.