C4 photosynthesis and transition of Kranz anatomy in cotyledons and leaves of Tetraena simplex.

abstract：:Molecular studies of apomictic plant species often detect more genotypic variation than predicted from their assumed reproductive mode. The two most commonly invoked mechanisms to explain these high levels of variation are recombination, via facultative sexuality, and mutation. The potential for sexual reproduction in...

journal_title：American journal of botany

authors： Houliston GJ,Chapman HM

更新日期：2004-01-01 00:00:00

abstract：:The micromorphology of pits in tracheary elements was examined in 35 species representing 29 genera of Rosaceae and related families to evaluate the assumption that angiosperm pits are largely invariant. In most Rosaceae, pit membranes between fibers and tracheids frequently appear to have amorphous thickenings with a...

journal_title：American journal of botany

authors： Jansen S,Sano Y,Choat B,Rabaey D,Lens F,Dute RR

更新日期：2007-04-01 00:00:00

abstract：:We investigated the hypothesis that dandelion clones (Taraxacum officinale Weber, sensu lato; Asteraceae) differ in their floral stage timing characteristics under a constant set of environmental conditions. To test this hypothesis, plants representing nine different dandelion clones (identified by DNA fingerprinting)...

journal_title：American journal of botany

authors： Collier MH,Rogstad SH

更新日期：2004-11-01 00:00:00

abstract：:The biological nature of some symbioses is unclear because it is often not easy to discern whether the symbionts obtain any benefits from the association. Mastodia tessellata, a symbiosis between a leafy green alga and a fungus of uncertain phylogenetic position, is among the most investigated, controversial, and poor...

journal_title：American journal of botany

authors： Pérez-Ortega S,Ríos Ade L,Crespo A,Sancho LG

更新日期：2010-05-01 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

authors： Spooner DM,Ruess H,Arbizu CI,Rodríguez F,Solís-Lemus C

更新日期：2018-01-01 00:00:00

abstract：:Floral organogenesis and development of the tropical legume trees Haematoxylum campechianum (logwood) and H. brasiletto (brazilwood) were studied using scanning electron microscopy. The aims were to compare ontogenies, and to elucidate the relationships of Haematoxylum with other genera of Caesalpinieae, the basal tri...

journal_title：American journal of botany

authors： Tucker S,Kantz K

更新日期：1997-08-01 00:00:00

abstract：:Oxalate crystals are very common in angiosperms, but few descriptions of their macropattern (crystal types, their tissue distribution, and development) exist. Because unusually large prismatic crystals and druses, are known from pomegranate, we traced the development of crystal macropattern in various-aged leaf sample...

journal_title：American journal of botany

authors： Lersten NR,Horner HT

更新日期：2005-12-01 00:00:00

abstract：:Much of the ultraviolet-B radiation (UV-B) research on plants has concentrated on vegetative plant parts, and only a small fraction has dealt with the reproductive system. The present study analyzed pollen grains of 34 taxa germinated and grown under two levels of UV-B radiation (187 and 460 mW/m2) or no UV-B (control...

journal_title：American journal of botany

authors： Torabinejad J,Caldwell M,Flint S,Durham S

更新日期：1998-03-01 00:00:00

abstract：PREMISE OF THE STUDY:Microsatellite loci were developed from Imperata cylindrica, a traditional medicinal herb in Asia and among the top 10 worst invasive weeds in the world, to aid in the identification of the limits of asexual clonal individuals. METHODS AND RESULTS:A total of 21 microsatellite markers, including 18...

journal_title：American journal of botany

authors： Chiang YC,Tsai CC,Hsu TW,Chou CH

更新日期：2012-11-01 00:00:00

abstract：:The fresh weights of suspension cultures of pear (Pyrus communis) and quince (Cydonia oblonga) increased exponentially for 30 to 40 days after subculturing. Transferring pear cultures to media in which quince cultures had grown for 10 days resulted in a 70% inhibition of callus growth. Transferring quince cultures to ...

journal_title：American journal of botany

authors： Moore R

更新日期：1986-01-01 00:00:00

abstract：:Although theory has demonstrated rather low levels of gene flow are sufficient to counteract opposing mutation, drift, and selection, widespread recognition of the evolutionary importance of gene flow has come slowly. The perceived role of gene flow as an evolutionary force has vacillated over the last century. In the...

journal_title：American journal of botany

authors： Ellstrand NC

更新日期：2014-05-01 00:00:00

abstract：PREMISE OF THE STUDY:Species differ in their temperature germination niche. Populations of a species may similarly differ across the distribution range of the species. Anticipating the impacts of climate variability and change requires understanding the differential sensitivity to germination temperature among and with...

journal_title：American journal of botany

authors： Chamorro D,Luna B,Moreno JM

更新日期：2017-01-01 00:00:00

abstract：PREMISE OF THE STUDY:Climate cycles of the Quaternary have impacted plants at a global scale, leaving behind a complex genetic legacy. Species of the northern Rocky Mountains of North America were exposed to more uniform glacial patterns than the central and southern ranges, where synergistic relationships between temp...

journal_title：American journal of botany

authors： Fuller RS,McGlaughlin ME

更新日期：2019-03-01 00:00:00

abstract：PREMISE OF THE STUDY:Recurrent formation of polyploid taxa is a common observation in many plant groups. Haploid, cytoplasmic genomes like the plastid genome can be used to overcome the problem of homeologous genes and recombination in polyploid taxa. Fragaria (Rosaceae) contains several octo- and decaploid species. We...

journal_title：American journal of botany

authors： Dillenberger MS,Wei N,Tennessen JA,Ashman TL,Liston A

更新日期：2018-05-01 00:00:00

abstract：:Individual plants of Asclepias exaltata (Asclepiadaceae) typically express an unusual self-incompatibility system under single-gene control. Hand-pollinations performed in six natural populations detected occasional self-fertile plants. The frequency of self-fertile individuals ranged from 0 to 34.0% and differed sign...

journal_title：American journal of botany

authors： Lipow SR,Broyles SB,Wyatt R

更新日期：1999-08-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Despite the ecological, economic, and cultural importance of the palm Mauritia flexuosa in Amazonia, knowledge of its reproductive biology is scarce. Previous observations of this species suggested beetles as the probable pollinator, but experimental work to confirm this hypothesis was...

journal_title：American journal of botany

authors： Khorsand Rosa R,Koptur S

更新日期：2013-03-01 00:00:00

abstract：:Phylogenetic analysis of DNA sequences of the chloroplast genes rcbL and ndhf revealed a highly supported clade composed of the families Plantaginaceae, Callitrichaceae, and Hippuridaceae in close association with the model organism Antirrhinum majus and other members of family Scrophulariaceae. Plantago has miniature...

journal_title：American journal of botany

authors： Reeves P,Olmstead R

更新日期：1998-08-01 00:00:00

abstract：:A detailed study of ascomal morphology and development in Cercophora palmicola showed that ontogeny is ascohymeniaceous, giving rise to an ostiolate perithecium. Ascomal initials consist of a coiled ascogonium surrounded by several layers of hyphae whose cells become pseudoparenchymatous. The centrum of the young asco...

journal_title：American journal of botany

authors： Hanlin RT

更新日期：1999-06-01 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

authors： Mercer KL,Alexander HM,Snow AA

更新日期：2011-06-01 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

authors： Méndez M

更新日期：2001-10-01 00:00:00

abstract：:Multiply sired fruits provide unambiguous evidence that pollen from two or more donors was deposited on a stigma and successfully fertilized ovules. Such multiple paternity within fruits can have important consequences for both parental and offspring fitness, but little is known about the frequency of multiple paterni...

journal_title：American journal of botany

authors： Mitchell RJ,Karron JD,Holmquist KG,Bell JM

更新日期：2005-05-01 00:00:00

abstract：:Morphology and development of the female flowers in Geonoma interrupta are described and compared with other taxa within Arecaceae. Inflorescences are pleiothyrses. Cincinni are immersed in pits and arranged according to the Fibonacci pattern along the rachillae. The gynoecium is composed of three free carpels in earl...

journal_title：American journal of botany

authors： Stauffer FW,Rutishauser R,Endress PK

更新日期：2002-02-01 00:00:00

abstract：:Multicellularity has evolved at least once in every major eukaryotic clade (in all ploidy levels) and numerous times among the prokaryotes. According to a standard multilevel selection (MLS) model, in each case, the evolution of multicellularity required the acquisition of cell-cell adhesion, communication, cooperatio...

journal_title：American journal of botany

authors： Niklas KJ

更新日期：2014-01-01 00:00:00

abstract：:Five plant communities in Western Australia, as well as selected desert and Rocky Mountain species of the western USA, were surveyed to evaluate associations among leaf structure, orientational properties, and the sunlight exposure and precipitation characteristic of each community. Selected leaf structural features h...

journal_title：American journal of botany

authors： Smith W,Bell D,Shepherd K

更新日期：1998-01-01 00:00:00

abstract：:Genetic diversity at variable-number-tandem-repeat (VNTR) loci was examined in the common cattail, Typha latifolia (Typhaceae), using three synthetic DNA probes composed of tandemly repeated "core" sequences (GACA, GATA, and GCAC). The principal objectives of this investigation were to determine whether: (1) the previ...

journal_title：American journal of botany

authors： Keane B,Pelikan S,Toth GP,Smith MK,Rogstad SH

更新日期：1999-09-01 00:00:00

abstract：:Investigations of the Middle Eocene Princeton Chert reveal evidence for the connection of lauraceous flowers to fruits through a developmental series. Youngest fruits are found with attached floral remnants. Later stages show receptacle enlargement, fruit wall thickening, and the development of abundant sclereid clust...

journal_title：American journal of botany

authors： Little SA,Stockey RA,Penner B

更新日期：2009-03-01 00:00:00

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 effe...

journal_title：American journal of botany

authors： Desrochers A,Rieseberg L

更新日期：1998-06-01 00:00:00

abstract：:Correlations were examined between habitat characters and clonal structures determined by the RAPD (random amplified polymorphic DNA) assay in five populations of Oryza rufipogon in China. Nine of 175 decameric primers were used in the study because they reproducibly amplified polymorphisms. The extent of clonality to...

journal_title：American journal of botany

authors： Xie ZW,Lu YQ,Ge S,Hong DY,Li FZ

更新日期：2001-06-01 00:00:00

abstract：:In volume 97(2) of the American Journal of Botany (pp. 268-275), we published an article entitled "Structural, physiological, and stable carbon isotopic evidence that the enigmatic Paleozoic fossil Prototaxites formed from rolled liverwort mats". Here, we respond to a letter and a commentary on our article in the pres...

journal_title：American journal of botany

authors： Graham LE,Cook ME,Hanson DT,Pigg KB,Graham JM

更新日期：2010-07-01 00:00:00

abstract：PREMISE OF THE STUDY:Ferns and lycophytes are the only extant land plants with two free-living generations (sporophytes and gametophytes); hence, a single species may have two different distributions. The distribution of the gametophytes of most fern species, which are much smaller in size than sporophytes, are almost ...

journal_title：American journal of botany

authors： Ebihara A,Yamaoka A,Mizukami N,Sakoda A,Nitta JH,Imaichi R

更新日期：2013-04-01 00:00:00