Abstract：
:In turnip mitochondria the cox2 gene is partially contained within a 2-kb (kilobase) direct repeat that is the site of homologous recombination events that generate subgenomic molecules. Because of its partial presence within the direct repeat, the turnip cox2 gene exists in four genomic contexts, two on the master chromosome and one on each of the subgenomic circles. In order to gain information on the expression of plant mitochondrial genes that exist in multiple genomic contexts and on plant mitochondrial recombination repeats in general we have characterized all four copies of the turnip 2-kb repeat and the cox2 gene. DNA sequence analysis indicates that the turnip high-frequency recombination repeat is 2424 bp in length. All but the last 58 bp of the cox2 gene is contained within the repeat, resulting in the presence of two intact cox2 genes and two pseudogenes. An intact cox2 gene and a pseudogene are found on the master chromosome (218 kb). An intact cox2 gene is also found on the 135-kb subgenomic circle, while a pseudogene is found on the 83-kb subgenomic circle. The turnip cox2 gene is unique because it lacks the first or 5' intron and contains the second or 3' intron previously found only in the carrot. The turnip intron is a group II intron that has high similarity (94.7%) with the second intron in carrot; also it is in precisely the same position within the gene. Transcript mapping studies using locus-specific probes reveal stable transcripts from the intact genes but not from the pseudogenes.
journal_name
Am J Botjournal_title
American journal of botanyauthors
Dong F,Wilson K,Makaroff Csubject
Has Abstractpub_date
1998-02-01 00:00:00pages
153issue
2eissn
0002-9122issn
1537-2197pii
85/2/153journal_volume
85pub_type
杂志文章abstract：:Gregor Mendel was a 19(th) century priest and botanist who developed the fundamental laws of inheritance. The year 2000 marked a century since the rediscovery of those laws and the beginning of genetics. Although Mendel is now recognized as the founder of genetics, significant controversy ensued about his work through...
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 OF THE STUDY:The perennial feather moss Hylocomium splendens is one of the most widely distributed and common bryophytes in the Northern Hemisphere and has, because of its capacity to grow under a wide range of environmental conditions, been used as a biomonitor for atmospheric metal deposition in Europe. METH...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1200028
更新日期：2012-09-01 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: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：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：:Partial cambial mortality is a growth form that is characteristic of Pinus aristata trees. To better elucidate their cambial death pattern, tree size and aspect of cambial death data were gathered from three Pinus aristata forests in central Colorado, USA. Stripping frequency tended to be higher for larger diameter cl...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：2001-04-01 00:00:00
abstract：PREMISE OF THE STUDY:Large phylogenies can help shed light on macroevolutionary patterns that inform our understanding of fundamental processes that shape the tree of life. These phylogenies also serve as tools that facilitate other systematic, evolutionary, and ecological analyses. Here we combine genetic data from pu...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.1002/ajb2.1019
更新日期：2018-03-01 00:00:00
abstract：:Viability of long-distance pollen links ecological models to the genetic structure of forest tree populations, determining how forests will adapt to climate change and how far genes flow from genetically modified (GM) pine plantations. Addressing this landscape-scale inquiry is feasible when the pollen source, the del...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.0900255
更新日期：2010-05-01 00:00:00
abstract：UNLABELLED:• PREMISE OF THE STUDY:Floral traits play important roles in pollinator attraction and defense against floral herbivory. However, plants may experience trade-offs between conspicuousness to pollinators and herbivore attraction. Comparative studies provide an excellent framework to examine the role of multip...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1400171
更新日期：2014-08-01 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：UNLABELLED: PREMISE OF THE STUDY:Verbenaceae consist of trees, shrubs, lianas, and herbs distributed primarily in Latin America, where they occur in a wide array of ecosystems. A second center of diversity exists in Africa. Competing morphology-based classifications that rely on different traits conflict in significan...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1000144
更新日期：2010-10-01 00:00:00
abstract：PREMISE OF THE STUDY:Species formation is an intuitive endpoint of reproductive isolation, but circumscribing taxa that arise during speciation can be difficult because of gene flow, morphological continuity, hybridization or polyploidization, and low sequence variation among newly diverged lineages. Nonetheless, speci...
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
abstract：:Expansion of Typha domingensis into areas previously dominated by Cladium jamaicense in the Florida Everglades has been linked to anthropogenic phosphorus (P) enrichment and increased hydroperiod. The principal stress factor for plants in flooded soils is biochemical reduction, the intensity of which is measured as re...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.90.5.736
更新日期：2003-05-01 00:00:00
abstract：:Several alpine species have outlying populations in the lowlands and lower mountains north of the Alps. These small, isolated populations are usually described as either (1) glacial relics, (2) descendants from populations living on forelands and moraines during the ice ages, or (3) populations founded by long-distanc...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：2000-04-01 00:00:00
abstract：:Size, allometry, and mechanical design were measured for trees of three canopy species in a tropical rain forest in French Guiana. Mechanical design was expressed as the safety factor, using the elastic-stability model, and the wind resistance factor, using the constant-stress model. Changes with ontogeny were describ...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：1998-02-01 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
pub_type： 杂志文章
doi：10.1002/ajb2.1259
更新日期：2019-03-01 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：PREMISE OF THE STUDY:Elucidating the factors that determine the abundance and distribution of species remains a central goal of ecology. It is well recognized that genetic differences among individual species can affect the distribution and species interactions of dependent taxa, but the ecological effects of genetic d...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1100137
更新日期：2011-10-01 00:00:00
abstract：UNLABELLED:• PREMISE OF THE STUDY:Contact zones between diploids and their autopolyploid descendants represent a unique evolutionary venue for studying polyploid establishment, cytotype coexistence, and interactions. Here, we examine cytotype coexistence in a diploid-tetraploid contact zone of a perennial herb, Cardam...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1500052
更新日期：2015-08-01 00:00:00
abstract：UNLABELLED: PREMISE OF THE STUDY:Allometric relationships among the dimensions of leaf cells, cell walls, and tissues, and whole-leaf thickness and area are likely to have key implications for leaf construction and function, but have remained virtually untested, despite the explosion of interest in allometric analysis...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1200608
更新日期：2013-10-01 00:00:00
abstract：:Biogeographical studies of lichens used to be complicated because of the large distribution ranges of many species. Molecular systematics has revitalized lichen biogeography by improving species delimitation and providing better information about species range limitations. This study focuses on the major clade of trop...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.0900140
更新日期：2010-04-01 00:00:00
abstract：PREMISE OF THE STUDY:Over one-third of the native flowering plant species in the Hawaiian Islands are listed as federally threatened or endangered. Lack of sufficient pollination could contribute to reductions in populations, reproduction, and genetic diversity among these species but has been little studied. METHODS:...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.1002/ajb2.1233
更新日期：2019-02-01 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
pub_type： 杂志文章,评审
doi：10.3732/ajb.1300314
更新日期：2014-01-01 00:00:00
abstract：PREMISE OF THE STUDY:Microsatellite markers of an important medicinal plant, Eurycoma longifolia (Simaroubaceae), were developed for DNA profiling and genetic diversity studies. METHODS AND RESULTS:Eighteen polymorphic microsatellite loci were developed for E. longifolia. The primers were designed from a genomic libra...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1000469
更新日期：2011-05-01 00:00:00
abstract：:Leaf habit correlates with multiple physiological traits. Understanding ecophysiology is therefore dependent on knowledge of leaf habit. A variety of leaf habits exists within forest understory plant communities. Oxalis acetosella is one such understory plant and has long been considered a wintergreen, meaning that it...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.91.9.1371
更新日期：2004-09-01 00:00:00
abstract：UNLABELLED:• PREMISE OF THE STUDY:Flower color is one of the best-studied floral traits in terms of its genetic basis and ecological significance, yet few studies have examined the processes that shape its evolution across deep timescales. Advances in comparative methods along with larger phylogenies for floral radiat...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1500163
更新日期：2015-07-01 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
pub_type： 杂志文章
doi：
更新日期：1999-08-01 00:00:00
abstract：PREMISE OF THE STUDY:Evolutionary and biogeographic history, including past environmental change and diversification processes, are likely to have influenced the expansion, migration, and extinction of populations, creating evolutionary legacy effects that influence regional species pools and the composition of communi...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.1002/ajb2.1049
更新日期：2018-03-01 00:00:00
abstract：:The circumscription and relationships of genera within the tribe Melanthieae (29 representative taxa) were evaluated using parsimony analyses of ITS (nuclear ribosomal) and trnL-F (plastid) DNA sequence data, alone and in combination. Proposed new generic circumscriptions, strongly supported by the tree statistics and...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：2001-09-01 00:00:00
abstract：:Field surveys of cynipid gall-inducer occurrences on Quercus species were conducted in Florida, North Carolina, and Pennsylvania, USA. All cynipids demonstrated strong host species and organ fidelity. One result of this specialization is effective niche partitioning among cynipids. The host-association patterns of the...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：1998-08-01 00:00:00
