Experimental eco-physiology of Passiflora edulis.
Item
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Title
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Experimental eco-physiology of Passiflora edulis.
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Identifier
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AAI9720084
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identifier
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9720084
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Creator
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Dial, Pattan J.
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Contributor
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Adviser: Dwight T. Kincaid
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Date
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1997
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Language
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English
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Publisher
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City University of New York.
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Subject
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Biology, Ecology | Biology, Plant Physiology
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Abstract
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With an experimental eco-physiological and morphometric approach, variations in leaf shape were quantified in the economically important neotropical vine, Passiflora edulis f. flavicarpa Deg. (Passifloraceae) after 200 days growth in the greenhouse. In contrast to 18% more two-lobed leaves and 15% less entire leaves in long-term drought, no two-lobed leaves were produced by cloned vines in nitrogen deprived conditions. With seedlings, 13% less two-lobed leaves and 9% more unlobed leaves were evident in nitrogen deprived plants. There was no change in the frequency of leaf types of cloned vines, given a 14-fold difference in PAR, as well as between wild and cultivated plants. Droughted vines produced smaller leaves, thinner leaves, and leaves that were more deeply lobed and of lower water potential. With a greater leaf specific mass (LSM), genet #705 was more drought tolerant than other genets. In a comparison of coefficients of variation of chlorophyll and LSM, a reallocation of resources along the vine occurred, with two-lobed leaves higher up the vine benefitting from chlorophyll and LSM reallocation. In shade, there was a monotonic increase in leaf size going from entire to one-lobed to two-lobed leaves. Entire leaves from a wet field site in Guyana had greater ISM than two-lobed leaves.;Photosynthesis and water use efficiency varied between unlobed and lobed leaves. Vines grown in far red (FR) light had reduced chlorophyll level compared to a red light treatment. There was no FR photomorphogenetic effect on leaf shape. Stomatal density and width of two-lobed leaves were greater than those of entire leaves. A worldwide survey of leaf types from greenhouse plants, averaged 32% unlobed, 9% one-lobed, and 59% two-lobed leaves. Carbon allocation to main veins of unlobed leaves increased steeply beyond the 7000 mm{dollar}\sp2{dollar} leaf area size, while vein mass of two-lobed leaves was much less in leaves greater than 7000 mm{dollar}\sp2{dollar} surface area. Two-lobed leaves, with higher stomatal density, larger stomates, thicker leaves, higher chlorophyll concentration, and larger size, coupled with less vein mass may explain in part the adaptive significance of these leaves as a more productive photosynthetic organ than unlobed leaves.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
