Abstract:
:The desert moss Syntrichia caninervis exhibits one of the most skewed sex ratios in the plant kingdom, with female individuals far outnumbering male individuals (exceeding 14♀:1♂). The "cost of sex hypothesis" derives from allocational theory and predicts that the sex which is most expensive should be the rarer sex. This hypothesis, which, as considered here represents the realized cost of sexual reproduction, is contingent upon two assumptions that are explored: (1) that male sex expression is more expensive than female sex expression, and (2) that sexual reproduction is resource limited. Using inflorescence biomass and discounting sperm, male sex expression was found to be in the neighborhood of one order of magnitude more expensive than female sex expression, and this difference is reflected in higher numbers of gametangia per male inflorescence, presence of paraphyses in male inflorescences, and a much longer developmental time for male inflorescences. The realized cost of female reproduction from two communities dominated by S. caninervis was found to be lower than the realized cost of male sexual reproduction. Resource-limited reproduction was assessed by determining the frequency of sporophyte abortion, the age distribution of sporophyte abortions, and patterns of sporophyte abortion that may be density dependent. Among ten sexually reproducing populations, abortive sporophytes occurred at a frequency of 0.64. Abortive sporophytes averaged 8% the mass of mature sporophytes, and cohort sporophytes from the same individual female were found to abort in a density-dependent pattern. We conclude that the two assumptions, upon which the cost of sex hypothesis depends, are supported.
journal_name
Am J Botjournal_title
American journal of botanyauthors
Stark LR,Mishler BD,McLetchie DNsubject
Has Abstractpub_date
2000-11-01 00:00:00pages
1599-608issue
11eissn
0002-9122issn
1537-2197pii
87/11/1599journal_volume
87pub_type
杂志文章abstract::Breakdown of genetically enforced self-incompatibility (SI), an extremely common and important evolutionary transition in plants, has conventionally been conceived as a qualitative rather than a quantitative change. We evaluated qualitative and quantitative variation in SI for four populations of Witheringia solanacea...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.93.4.592
更新日期:2006-04-01 00:00:00
abstract:PREMISE:Variation in seedling emergence timing is considered adaptive over the long term in wild populations, but early emergence can result in a fitness advantage. To explore the adaptive significance of seedling emergence timing, it should be studied under realistic conditions and in the context of other traits that ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1000408
更新日期:2011-06-01 00:00:00
abstract::Species of Collinsia and Tonella, the two sister genera of self-compatible annuals that constitute tribe Collinsieae, show extensive variation in floral size and morphology and in patterns of stamen and style elongation during the life of the flower (anthesis). We used a nuclear ribosomal ITS phylogeny, independent co...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.89.1.37
更新日期:2002-01-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1100367
更新日期:2012-03-01 00:00:00
abstract::Seed size and cotyledon morphology are two key juvenile traits that have evolved in response to changes in plant species life-history strategies and habitat associations. Correlations of these traits with each other and with other juvenile traits were examined for 70 species of trees and shrubs in Kibale National Park...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.92.6.972
更新日期:2005-06-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1404
更新日期:2020-02-01 00:00:00
abstract:PREMISE OF THE STUDY:The species boundaries of wild and cultivated potatoes are controversial, with most of the taxonomic problems in the cultivated potato clade. We here provide the first in-depth phylogenetic study of the cultivated potato clade to explore possible causes of these problems. METHODS:We examined 131 d...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1008
更新日期:2018-01-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.93.9.1357
更新日期:2006-09-01 00:00:00
abstract:PREMISE:Spiny pollen has evolved independently in multiple entomophilous lineages. Sexual selection may act on exine traits that facilitate male mating success by influencing the transfer of pollen from the anther to the body of the pollinator, while natural selection acts to increase pollen survival. We postulated tha...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1428
更新日期:2020-02-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600278
更新日期:2017-01-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1997-05-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1400143
更新日期:2014-10-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1200643
更新日期:2013-10-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.95.3.353
更新日期:2008-03-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1000226
更新日期:2011-05-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/j.1537-2197.1993.tb13838.x
更新日期:1993-05-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1500017
更新日期:2015-06-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.0900059
更新日期:2009-10-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.92.4.625
更新日期:2005-04-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
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更新日期:2003-09-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.92.2.337
更新日期:2005-02-01 00:00:00
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更新日期:2007-01-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1061
更新日期:2018-03-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2000-06-01 00:00:00
abstract::Caryophyllaceae is a principally holarctic family including around 2200 species often classified into the three subfamilies Alsinoideae, Caryophylloideae, and Paronychioideae. Complex and possibly homoplasious morphological characters within the family make taxa difficult to delimit and diagnose. To explore part of th...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.93.3.399
更新日期:2006-03-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章,评审
doi:10.3732/ajb.1000289
更新日期:2011-03-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.90.2.207
更新日期:2003-02-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1259
更新日期:2019-03-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1400369
更新日期:2014-12-01 00:00:00
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journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1997-08-01 00:00:00