Abstract：
:Self-incompatibility (SI) is an effective method for limiting self-fertilization in flowering plant species, but there are circumstances in which an otherwise functional SI system may fail. One of the most intriguing of these is the induction of selfing by mixed loads of self and heterospecific pollen (the mentor effect) because it is likely to occur under natural conditions, such as in hybrid zones. Here we conducted a series of controlled crosses to determine whether mentor effects operate in two SI annual species, Helianthus annuus and H. petiolaris, and whether the failure of SI results in a decrease in the frequency of hybridization between these two species. Of the 1396 achenes examined from pollen mixtures that included varying ratios of self, intraspecific compatible, and interspecific pollen, 71 (5.1%) were selfed. Selfing frequencies were significantly less than expected based on pollen ratios, except when the proportion of intraspecific compatible pollen was low. Hybridization frequencies from these same pollen ratios averaged 41.8% with H. annuus as the maternal species and 13.3% with H. petiolaris as the mother. Analysis of 1404 achenes from pollen mixtures that excluded self pollen resulted in hybridization frequencies for H. annuus (42.2%) and H. petiolaris (18.2%) that do not differ significantly from those including self pollen. Thus, mentor effects do not appear to play an important role in reproductive isolation between these species. On the other hand, even a modest increase in self-fertilization in hybrid populations, such as that due to mentor effects, could enhance the probability of hybrid species establishment.
journal_name
Am J Botjournal_title
American journal of botanyauthors
Desrochers A,Rieseberg Lsubject
Has Abstractpub_date
1998-06-01 00:00:00pages
770issue
6eissn
0002-9122issn
1537-2197pii
85/6/770journal_volume
85pub_type
杂志文章abstract：:The mode of chloroplast DNA (cpDNA) inheritance was investigated in the genus Larrea (Zygophyllaceae) by polymerase chain reaction (PCR) amplification of cpDNA fragments using three pairs of chloroplast universal primers. A total of 20 F(1)s from interspecific crosses among five different taxa in the section Bifolium ...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：2000-10-01 00:00:00
abstract：PREMISE OF THE STUDY:High intraspecific cytogenetic variation in the sedge genus Carex (Cyperaceae) is hypothesized to be due to the "diffuse" or non-localized centromeres, which facilitate chromosome fission and fusion. If chromosome number changes are dominated by fission and fusion, then chromosome evolution will re...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1000046
更新日期：2011-01-01 00:00:00
abstract：:The effect of microgravity on cellulose synthesis using the model system of Acetobacter xylinum was the subject of recent investigations using The National Aeronautics and Space Administration's Reduced Gravity Laboratory, a modified KC-135 aircraft designed to produce 20 sec of microgravity during the top of a parabo...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：1992-11-01 00:00:00
abstract：:Contact forces are important in maintaining the twining habit of viny stems. A stem twining around a supporting pole puts itself into tension and uses a helical geometry to generate normal loads that are large relative to stem mass per unit length (Silk and Hubbard, Journal of Biomechanics 24(7):599-606, 1991). An ele...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：1997-08-01 00:00:00
abstract：PREMISE OF THE STUDY:We developed microsatellite loci for the biomass crop Miscanthus sinensis to investigate genetic diversity and population structure of M. sinensis and its closely related species. METHODS AND RESULTS:Fourteen microsatellite loci were identified from an enriched genomic library of M. sinensis and t...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1100040
更新日期：2011-07-01 00:00:00
abstract：:Phylogenetic relationships of 38 species of the Alibertia group (Rubiaceae) and two outgroup species were investigated using the nuclear ribosomal 5S nontranscribed spacer (5S-NTS) and the internal transcribed spacers (ITS). Analysis of the data sets separately and in combination resulted in several well-supported and...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：2000-07-01 00:00:00
abstract：PREMISE OF THE STUDY:Virtually nothing is known about what actually happens during prolonged dormancy, the period during which significant proportions of geophyte populations do not sprout after seasonal dormancy but remain alive underground, to emerge again 1 or more years later. This study investigated the fate of pe...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1000262
更新日期：2011-02-01 00:00:00
abstract：:The pollination biology of the cactus Pachycereus pecten-aboriginum was studied in a tropical location in western Mexico (ca. 18° N latitude) to compare with data from a northern population (ca. 28° N latitude). Throughout this range, the nectar-feeding bat Leptonycteris curasoae is resident within the tropics but mig...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.91.6.850
更新日期：2004-06-01 00:00:00
abstract：:The tribe Genisteae includes genera of great ecological importance in Mediterranean countries because they are dominant elements of many plant communities. Genetic variation and diversification patterns in Stauracanthus (Genisteae) provide information relevant for the study of the processes of diversification in relat...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.95.1.98
更新日期：2008-01-01 00:00:00
abstract：:Xylem of the orchids studied provided unusually favorable material to demonstrate how conductive tissue evolves in monocotyledons. In the end walls of tracheary elements of many Orchidaceae, remnants of pit membranes were observed with scanning electron microscopy and minimally destructive methods. The full range from...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.93.7.963
更新日期：2006-07-01 00:00:00
abstract：:Additional information on the morphology of the vegetative ultimate branches of Archaeopteris roemeriana was obtained by uncovering compression specimens collected in Upper Devonian deposits in Belgium. For the first time, anisophylly, previously inferred from anatomical studies, is demonstrated on one species of the ...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：2001-04-01 00:00:00
abstract：:The relationship between pollen and progeny performance has been a subject of many studies but the evidence for pollen-tube growth rate as an indicator of progeny fitness is equivocal. We used an anemophilous tree, Betula pendula, to examine the relationship between pollen-tube growth rate and seed and seedling perfor...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：2001-05-01 00:00:00
abstract：PREMISE:Adaptation to harsh edaphic substrates has repeatedly led to the evolution of edaphic specialists and generalists. Yet, it is unclear what factors promote specialization versus generalization. Here, we search for habitat use patterns associated with serpentine endemics (specialists) and serpentine tolerators (g...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.1002/ajb2.1285
更新日期：2019-05-01 00:00:00
abstract：:Sequence data from the intron and spacer of the trnL-F chloroplast region elucidate the phylogenetic relationships of the tribe Diseae (Orchidoideae: Orchidaceae). Within Diseae, 41 species of Disa, two of Brownleea, three of Satyrium, and two of Corycium were included, with five species of Habenaria sensu lato (Orchi...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：2001-11-01 00:00:00
abstract：:The ultrastructure of Typha latifolia pollen was examined as a function of pollen moisture content and incubation temperature, in order to identify possible lesions induced by imbibitional chilling. A syndrome of structural traits was found which characterizes damaged grains. Compared to viable grains, the protoplas...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：1988-01-01 00:00:00
abstract：:Interspecific hybridization is considered a possible mechanism of plant diversification. The Andes are a hotspot of biodiversity, but hybridization in Andean taxa has so far not been investigated intensively. The current study investigates crossability in Caiophora (Loasaceae subfam. Loasoideae) by experimental inters...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.2007403
更新日期：2008-09-01 00:00:00
abstract：UNLABELLED:• PREMISE OF THE STUDY:The ability to respond to environmental change via phenotypic plasticity may be important for plants experiencing disturbances such as climate change and plant invasion. Responding to belowground competition through root plasticity may allow native plants to persist in highly invaded ...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1400234
更新日期：2015-01-01 00:00:00
abstract：:Tacca, a genus of tropical herbs, possesses near black flowers, conspicuous involucral bracts and whisker-like filiform bracteoles. These features have been assumed to function as a "deceit syndrome" in which reproductive structures resemble decaying organic material attracting flies that facilitate cross-pollination ...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.92.3.517
更新日期：2005-03-01 00:00:00
abstract：:In monocarpic plants, reproduction is closely associated with senescence, which is itself often correlated to specific environmental signals. Floerkea proserpinacoides (Limnanthaceae) is a spring ephemeral annual of the deciduous forests of eastern North America. The phenology of its growth and reproduction is conside...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.92.3.438
更新日期：2005-03-01 00:00:00
abstract：:Cacti are a large and diverse group of stem succulents predominantly occurring in warm and arid North and South America. Chloroplast DNA sequences of the trnK intron, including the matK gene, were sequenced for 70 ingroup taxa and two outgroups from the Portulacaceae. In order to improve resolution in three major grou...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.89.2.312
更新日期：2002-02-01 00:00:00
abstract：:Accurate estimates of inbreeding depression are necessary in order to predict the evolutionary dynamics of a population, but many studies estimate inbreeding depression based solely on components of female function such as fruit set, seed set, and seed quality. Because total fitness is achieved through both male and f...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.92.1.107
更新日期：2005-01-01 00:00:00
abstract：:Gaura (Onagraceae: Onagreae) is a small North American genus of 21 species consisting mostly of night-blooming, moth-pollinated annuals and perennials. The current infrageneric classification based on differences in habit, floral symmetry, and fruit morphology recognizes eight sections within the genus. We examine the...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.91.1.139
更新日期：2004-01-01 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：:There have been three periods of significant discovery in the exploration of fern and lycophyte genetics. First, during the 1930s, Andersson-Kottö conducted crossing studies on ferns. The publication of Manton's magnum opus on fern chromosomes in 1950 stimulated the second. The third emerged from Klekowski's 1973 Amer...
journal_title：American journal of botany
pub_type： 杂志文章,评审
doi：10.3732/ajb.1400317
更新日期：2014-12-01 00:00:00
abstract：:Recent molecular phylogenetic studies of Solanaceae have identified many well-supported clades within the family and have permitted the creation of a phylogenetic system of classification. Here we estimate the phylogeny for Iochrominae, a clade of Physaleae sensu Olmstead et al. (1999), which contains 34 Andean specie...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.93.8.1140
更新日期：2006-08-01 00:00:00
abstract：PREMISE:Hyperaccumulation of heavy metals in plants has never been documented from Central America or Mexico. Psychotria grandis, P. costivenia, and P. glomerata (Rubiaceae) have been reported to hyperaccumulate nickel in the Greater Antilles, but they also occur widely across the neotropics. The goals of this research...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.1002/ajb2.1362
更新日期：2019-10-01 00:00:00
abstract：:The origin of polyploid Bromus species of section Genea was investigated using molecular data. This group of annual species native from the Old-World is composed of three diploids, two tetraploids, one hexaploid, and one octoploid. Molecular cloning, sequencing, and phylogenetic analyses were performed on several acce...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.95.4.454
更新日期：2008-04-01 00:00:00
abstract：:Chloroplast DNA (cpDNA) is maternally inherited in the majority, but not all, of angiosperm species. The mode of inheritance of cpDNA is a critical determinant of its molecular evolution and of its population genetic structure. Here, we present the results of investigations of the inheritance of cpDNA in Silene vulgar...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.94.8.1333
更新日期：2007-08-01 00:00:00
abstract：PREMISE OF THE STUDY:Functional trait plasticity in resource capture traits has been suggested as an underlying mechanism promoting invasive species establishment and spread. Earlier studies on this mechanism treat invasiveness as a discrete characteristic (i.e., invasive vs. noninvasive) and do not consider the potent...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1600235
更新日期：2016-12-01 00:00:00
abstract：:Bamboo is considered useful for controlling landslides, but we observed numerous shallow-slope failures in forests of big node bamboo (Phyllostachys nidularia) in Sichuan, China. Therefore, we inventoried landslide occurrence and vegetation type along one valley. To quantify bamboo root anchorage, we performed uprooti...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.94.7.1129
更新日期：2007-07-01 00:00:00
