Abstract：
:To investigate the relationship between the altitudinal distribution of Quercus laceyi and Q. sideroxyla and their physiological responses to drought, we measured relative water content (RWC), water potentials (Ψ(predawn) and Ψ(midday)), photosynthesis (A(max)), stomatal conductance (g), chlorophyll fluorescence (F(v)/F(m)), and spectral reflectance (400-1100 nm) five times during a 7 wk acute drought. Quercus laceyi was drought tolerant, while Q. sideroxyla was a drought avoider; Q. laceyi tolerated lower RWC (Q. sideroxyla = 54%, Q. laceyi = 44%), Ψ(pd) (Q. sideroxyla = -2.6 MPa, Q. laceyi = -3.3 MPa), and Ψ(md) (Q. sideroxyla = -4.5 MPa, Q. laceyi = -6.6 MPa). The F(v)/F(m) also declined first in Q. sideroxyla in wk 6, whereas F(v)/F(m) did not decline in Q. laceyi until wk 7. A(max) and g fell in wk 4, 6, and 7 in drought seedlings of both species, suggesting a decline in CO(2) assimilation during the drought. Leaf spectral reflectance increased with time in response to decreases in leaf photosynthetic pigment concentrations in latter weeks of the drought. The results suggest a close association between the altitudinal distributions of these species and their adaptation to water stress.
journal_name
Am J Botjournal_title
American journal of botanyauthors
Poulos HM,Goodale UM,Berlyn GPdoi
10.3732/ajb.94.5.809subject
Has Abstractpub_date
2007-05-01 00:00:00pages
809-18issue
5eissn
0002-9122issn
1537-2197pii
94/5/809journal_volume
94pub_type
杂志文章abstract：:Clarkia (Onagraceae) is a genus of 42 annual species, mostly native to California, that has served as a model for many studies of plant evolutionary biology, particularly morphological, cytological, and genetic divergence; reproductive isolation; and speciation. Section Sympherica is the largest section with eight dip...
journal_title：American journal of botany
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journal_title：American journal of botany
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journal_title：American journal of botany
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journal_title：American journal of botany
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journal_title：American journal of botany
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journal_title：American journal of botany
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更新日期：2002-09-01 00:00:00
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journal_title：American journal of botany
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doi：
更新日期：1999-08-01 00:00:00
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更新日期：2001-04-01 00:00:00
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更新日期：1998-08-01 00:00:00
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更新日期：2000-08-01 00:00:00
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journal_title：American journal of botany
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更新日期：2001-04-01 00:00:00
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更新日期：2000-05-01 00:00:00
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