Abstract:
:Yucca glauca is a C(3) evergreen rosette species locally common in the C(4)-dominated grasslands of the central Great Plains. Most congeners of Y. glauca are found in deserts, and Y. glauca's morphological similarities to desert species (steeply angled leaves, evergreen habit) may be critical to its success in grasslands. We hypothesized that the evergreen habit of Y. glauca, coupled with its ability to remain physiologically active at cool temperatures, would allow this species to gain a substantial portion of its annual carbon budget when the C(4) grasses are dormant. Leaf-level gas exchange was measured over an 18-mo period at Konza Prairie in northeast Kansas to assess the annual pattern of potential C gain. Two short-term experiments also were conducted in which nighttime temperatures were manipulated to assess the cold tolerance of this species. The annual pattern of C gain in Y. glauca was bimodal, with a spring productive period (maximum monthly photosynthetic rate = 21.1 ± 1.97 μmol·m·s) in March through June, a period of midseason photosynthetic depression, and a fall productive period in October (15.6 ± 1.25 μmol·m·s). The steeply angled leaves resulted in interception of photon flux density at levels above photosynthetic saturation throughout the year. Reduced photosynthetic rates in the summer may have been caused by low soil moisture, but temperature was strongly related (r = 0.37) to annual variations in photosynthesis, with nocturnal air temperatures below -5°C in the late fall and early spring, and high air temperatures (>32°C) in the summer, limiting gas exchange. Overall, 31% of the potential annual carbon gain in Y. glauca occurred outside the "frost-free" period (April-October) at Konza Prairie and 43% occurred when the dominant C(4) grasses were dormant. Future climates that include warmer minimum temperatures in the spring and fall may enhance the success of Y. glauca relative to the C(4) dominants in these grasslands.
journal_name
Am J Botjournal_title
American journal of botanyauthors
Maragni LA,Knapp AK,McAllister CAsubject
Has Abstractpub_date
2000-02-01 00:00:00pages
230-6issue
2eissn
0002-9122issn
1537-2197pii
87/2/230journal_volume
87pub_type
杂志文章abstract::The balance between clonal and sexual reproduction can vary widely among plant populations, and the extent of clonality may be influenced by the combined effects of historical land use and variation in environmental conditions. We investigated patterns of clonal spread in five Trillium cuneatum populations, two in the...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.2007159
更新日期:2008-10-01 00:00:00
abstract::In the southern Appalachian mountains a subcanopy species, Rhododendron maximum, inhibits the establishment and survival of canopy tree seedlings. One of the mechanisms by which seedlings could be inhibited is an allelopathic effect of decomposing litter or leachate from the canopy of R. maximum (R.m.) on seed germina...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1999-11-01 00:00:00
abstract:PREMISE OF THE STUDY:In angiosperm seeds, the developing embryo acquires nutrients via a suspensor that typically undergoes programmed cell death (PCD) at the early cotyledon stage. However, in Leguminosae (the third largest angiosperm family), the suspensors can disappear at the heart-shaped stage (i.e., prior to the ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1100314
更新日期:2012-08-01 00:00:00
abstract:PREMISE OF THE STUDY:Expressed sequence tag (EST)-derived microsatellite markers were developed for Elaeocarpus photiniifolia, an endemic taxon of the Bonin Islands. METHODS AND RESULTS:Initially, a complementary DNA (cDNA) library was constructed by de novo pyrosequencing of total RNA extracted from a seedling. A tot...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1100391
更新日期:2012-02-01 00:00:00
abstract:PREMISE OF THE STUDY:It has been hypothesized that two flower types permit flexible allocation of resources to female and male functions, yet empirical evidence for the sex-allocation hypothesis remains scarce in gynomonoecious species. To characterize resource allocation to pistillate and perfect flowers and allocatio...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1600397
更新日期:2017-03-01 00:00:00
abstract:PREMISE OF THE STUDY:Uplift of the tropical Andes had a significant impact on the diversification of South American flora and fauna. Recent biogeographic inquiries have established patterns of Andean divergence, but investigations on ferns are scant. The fern genus Polystichum Roth (Dryopteridaceae) combines widespread...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1300191
更新日期:2014-02-01 00:00:00
abstract:PREMISE OF THE STUDY:Subtribe Hakeinae (526 spp.) represents a large Australian plant radiation central to our understanding of that flora's evolution and ecology. It contains Grevillea-the third largest plant genus in Australia and a group inferred to have among the highest diversification rates in the angiosperms. Ho...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1500195
更新日期:2015-10-01 00:00:00
abstract:UNLABELLED: PREMISE OF THE STUDY:Fuchsia (Onagraceae) anthers, pollen, and an ornithophilous Fuchsia-like flower from an earliest Miocene lacustrine diatomite deposit at Foulden Maar, southern New Zealand confirm a long record for Fuchsia in New Zealand and probably an equally long history for its distinctive honeyeat...
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
abstract::Senna (Leguminosae) is a large, widespread genus that includes species with enantiostylous, asymmetric flowers and species with extrafloral nectaries. Clarification of phylogenetic relationships within Senna based on parsimony analyses of three chloroplast regions (rpS16, rpL16, and matK) provides new insights on the ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.93.2.288
更新日期:2006-02-01 00:00:00
abstract::Understanding the role of geography and ecology in species divergence is central to the study of evolutionary diversification. We used climatic, geographic, and biological data from nine wild Andean tomato species to describe each species' ecological niche and to evaluate the likely ecological and geographical modes o...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.0900216
更新日期:2010-04-01 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
abstract::Phylogenetic relationships of eight species of Saintpaulia H. Wendl., 19 species of Streptocarpus Lindl. (representing all major growth forms within the genus), and two outgroups (Haberlea rhodopensis Friv., Chirita spadiciformis W. T. Wang) were examined using comparative nucleotide sequences from the two internal tr...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1997-07-01 00:00:00
abstract::Sex allocation models predict that cosexuality is stabilized by high allocation to attractive structures in pollen-limited species or by high allocation to shared structures that contribute to both genders. High investment in unilateral fixed costs favor the evolution of dioecy or gender change. With these predictions...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:2001-10-01 00:00:00
abstract::Dispersal is an important life history component. Seed settling velocity may be a useful surrogate for the measurement of dispersal ability in wind-dispersed plants, particularly those whose seeds have plumose dispersal structures. I measured settling velocities on seeds of eight species of Asteraceae, including annua...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/j.1537-2197.1992.tb13702.x
更新日期:1992-10-01 00:00:00
abstract:PREMISE OF THE STUDY:Phylogenetic incongruence between "gene trees" and "species trees" has been widely acknowledged in phylogenetic research. Conflicts may emerge from several processes including paralogy, hybridization, and incomplete lineage sorting. Although phylogenetic incongruence appears common, its impact on m...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1400527
更新日期:2015-04-01 00:00:00
abstract::Cladistic parsimony analyses of rbcL nucleotide sequence data from 171 taxa representing nearly all tribes and subtribes of Orchidaceae are presented here. These analyses divide the family into five primary monophyletic clades: apostasioid, cypripedioid, vanilloid, orchidoid, and epidendroid orchids, arranged in that ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:
更新日期:1999-02-01 00:00:00
abstract::Temporal and demographic aspects of the growth of Botrychium gallicomontanum and B. mormo were studied for 2 yr. A total of 219 B. gallicomontanum and 412 B. mormo plants were monitored in a prairie and maple-basswood forest, respectively. Growth events were divided into four stages: leaf emergence, leaf separation, s...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.89.10.1624
更新日期:2002-10-01 00:00:00
abstract::Madagasikaria andersonii is described here as a new genus and species of Malpighiaceae from Madagascar. The phylogenetic placement of Madagasikaria was estimated by using combined data from ndhF and trnL-F chloroplast sequences and phytochrome (PHYC) and ITS nuclear sequences. It forms a strongly supported clade with ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.89.4.699
更新日期:2002-04-01 00:00:00
abstract:PREMISE OF THE STUDY:Miscanthus, a nonfood plant with high potential as a biofuel, has been used in Europe and the United States. The selection of a cultivar with high biomass, photosynthetic efficiency, and stress resistance from wild populations has become an important issue. New genic microsatellite markers will aid...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1100071
更新日期:2011-08-01 00:00:00
abstract:PREMISE OF THE STUDY:Robust markers are required (inter alia) for assessing origins of Calophyllum inophyllum populations on the Bonin Islands, Japan. Therefore, informative expressed sequence tag (EST)-based microsatellite or simple sequence repeat (SSRs) markers in the species were sought. METHODS AND RESULTS:Using ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1100299
更新日期:2012-01-01 00:00:00
abstract:PREMISE OF STUDY:Sequence analyses for Pinaceae have suggested that extant genera diverged in the late Mesozoic. While the fossil record indicates that Pinaceae was highly diverse during the Cretaceous, there are few records of living genera. This description of an anatomically preserved seed cone extends the fossil re...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.1100568
更新日期:2012-06-01 00:00:00
abstract::Six of 14 species of Triteleia were studied. All possess septal nectaries, raphides in the ovary wall, an anatropous and crassinucellate ovule with a micropyle formed by the inner integument only, and parietal cells. A short and thick nucellus, which is not penetrated by the embryo sac, has a one-layered apical epider...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.90.6.937
更新日期:2003-06-01 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
abstract::Seedling establishment is central to population maintenance for nonclonal plant species. Plants with low recruitment rates are expected to have high survival rates, and life history theory indicates there should be a single curve for the trade-off between recruitment and mortality that applies to most or all plant spe...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.91.7.1147
更新日期:2004-07-01 00:00:00
abstract::Pedilanthus coalcomanensis was described from specimens collected by George B. Hinton in 1941 but was not collected again until 1999, when we found it in a tropical deciduous forest near Tehuantepec, in Chinicuila, Michoacán, Mexico. After analyzing Hinton's original collection notes, we concluded that this is the typ...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.89.9.1485
更新日期:2002-09-01 00:00:00
abstract::This paper reports the frequency of spontaneous amphiploids or neopolyploids in experimental interspecific hybrids in two annual sections of Gilia (Polemoniaceae, sects. Arachnion and Gilia, x = 9). In each section the species were intercrossed in numerous hybrid combinations to obtain an array of F1 hybrid types; sev...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.89.8.1197
更新日期:2002-08-01 00:00:00
abstract::Inbreeding depression is a critical factor countering the evolution of inbreeding and thus potentially shaping the evolution of plant sexual systems. Current theory predicts that inbreeding depression could have important evolutionary consequences, even in haploid-dominant organisms. To date, no data have been reporte...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.94.11.1853
更新日期:2007-11-01 00:00:00
abstract::New individuals in clonal populations arise through the recruitment of sexual or clonal offspring. The predominance of one type of regeneration over the other has been correlated with different selective environmental pressures. We compared the reproductive mode (sexual through seeds and vegetative through plantlets o...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.93.4.505
更新日期:2006-04-01 00:00:00
abstract::Axillary meristems play a fundamental role in inflorescence architecture. Maize (Zea mays) inflorescences are highly branched panicles because of the production of multiple types of axillary meristems. We used auxin transport inhibitors to show that auxin transport is required for axillary meristem initiation in the m...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.3732/ajb.94.11.1745
更新日期:2007-11-01 00:00:00
abstract:PREMISE:Although hybridization has played an important role in the evolution of many plant species, phylogenetic reconstructions that include hybridizing lineages have been historically constrained by the available models and data. Restriction-site-associated DNA sequencing (RADseq) has been a popular sequencing techni...
journal_title:American journal of botany
pub_type: 杂志文章
doi:10.1002/ajb2.1352
更新日期:2019-09-01 00:00:00