28 research outputs found
Utility of RAPD Markers in Evaluating the Status of the Hawaiian Tree Fern Cibotium x heleniae
Randomly amplified polymorphic DNA (RAPD) markers provide
data consistent with the conclusion based on morphological characters that the
recently named taxon Cibotium xheleniae is indeed of hybrid origin. This assertion
is supported by (I) placement of C. xheleniae intermediate to the parent
taxa, as determined by genetic similarity data; (2) location of C. xheleniae individuals
on a clade intermediate to the parent species in the cladistic analysis;
and (3) clustering of the C. xheleniae individuals between clusters of parental
individuals in principal components analysis. Additivity of parental genetic
markers in the putative hybrid ranged from 54 to 64%, providing additional
though modest support for the hypothesized origin of C. x heleniae. Our results
indicate that RAPD data can be of considerable value in assessing potential hybridity
of individuals in naturally occurring populations
A biosystematic study of the Muhlenbergia repens Complex (Poaceae)
Typescript (photocopy).A biosystematic treatment was made of the Muhlenbergia repens complex. Materials for morphological, anatomical, embryological, and cytological studies were collected from throughout the geographic region of this complex. Based on these studies six species are recognized: M. fastigiata, M. plumbea, M. repens, M. richardsonis, M. utilis, and M. villiflora. One new combination was made: M. villosa was submerged as a variety of M. villiflora. New biological descriptions are given for each of the recognized taxa. Floret vestiture was examined on each of the taxa by means of scanning electron microscopy. These investigations showed that, of the species traditionally referred to as "glabrous," three of the species examined were completely glabrous, with no vestiture of any kind, and two of the species had spikelets with minute or sparse pubescence on both lemma and palea. One species had florets with long villous macrohairs as previously described. This species and those with minute or sparse pubescence also have numerous papillae associated with the hairs. There is some evidence that the papillae represent non-functional or reduced macrohairs. A morphological examination was made on 117 populations of the complex. Phenetic and basic biostatistical techniques were used to delineate and define taxa. Principal components analysis, correlation and distance phenograms, and multivariate analysis were used to show spacial relationships among population clusters. Correlation coefficients, means, ranges, standard deviations, nested analysis of variance, and discriminant analysis were used to compare and define species. On the basis of these results, six species were defined. Detailed quantitative descriptions are given for leaf epidermal and internal anatomical characters. Characters of the abaxial epidermis and leaf transverse section were used to differentiate among the taxa. Differences between the varieties of M. villiflora were evident when leaves were viewed in transverse section. Leaf anatomical characters within the complex were typical of the Chloridoid-Eragrostoid type, this having been correlated with the C4 photosynthetic pathway, and specifically the NAD-me subtype. An indication was also found that rows of short cells on the epidermis of the leaf are only present if associated with sclerenchyma below the epidermal layer..
Development of a DNA Library for Native Hawaiian Plants
The native Hawaiian flora is under severe stress because of
habitat loss and effects of invasive plants and animals introduced into the ecosystem.
These factors are threatening to push many of the endemic species to
extinction. In an effort to provide a broad genetic base from which research
projects on native species may be initiated, DNA was isolated from endemic
and indigenous species from Hawai'i, Kaua'i, Uina'i, Maui, Moloka'i, and
O'ahu and included in a newly created Native Hawaiian Plants DNA Library.
DNA accession numbers and collection information are presented for 206 species
representing 75 families and 128 genera
Phylogeny and Biogeography of Pacific Rubus Subgenus ldaeobatus (Rosaceae) Species: Investigating the Origin of the Endemic Hawaiian Raspberry R. macraei
The endemic Hawaiian raspberries Rubus hawaiensis and R. macraei
(both subgenus Idaeobatus) had been thought to be closely related species until
recent molecular studies demonstrated otherwise. These studies suggest that
they are the products of separate colonizations to the Hawaiian Islands. Affinities
of R. hawaiensis to R. spectabilis of western North America were clearly
confirmed. However, no clear relation to R. macraei has been published. This
study was initiated to examine species of subg. Idaeobatus from the surrounding
Pacific region as well as species from other subgenera to better evaluate biogeographic
and phylogenetic affinities of R. macraei by means of chromosome
analysis and molecular data using the chloroplast gene ndhF. Results show that
R. macraei clusters in a clade with species of blackberries, subg. Rubus, and of
these it is most closely linked to R. ursinus. Chromosomally, R. macraei is
2n = 6x = 42, a number that would be a new report for subg. Idaeobatus. However,
polyploidy is common in subg. Rubus. Analyses indicate that R. macraei and
R. hawaiensis are derived from separate colonizations from North America and
that similarities between them are due to convergent evolution in the Hawaiian
environment
Hawaiian Plant DNA Library II: Endemic, Indigenous, and Introduced Species
The Hawaiian Plant DNA Library of endemic and indigenous
plant species preserves genetic material from all Hawaiian Islands. DNA accession
numbers are reported here for 155 native species representing 92 genera
and 48 families. Federal status of endangered species is indicated where applicable.
Accessions for 71 species in 52 genera and 10 families of introduced species
are also reported. Pest and invasive species are also indicated
Genetic Diversity of the Endangered Endemic Hawaiian Genus Kokia (Malvaceae) 1
Abstract The genetic diversity of all three extant species of the Hawaiian endemic tree genus, Kokia, was examined using analyses of RAPD markers. All three species are federally endangered, two (K. cookei and K. drynarioides) critically so, and one (K. kauaiensis) is rare but with several populations. Samples extracted were PCR amplified with 10 primers to yield 115 genetic markers. Analyses indicate that genetic variation is present in all three species; a surprising result given that K. cookei survives only from self-fertilized propagules of the single surviving individual that was grafted on to the root stock of a related species, K. drynarioides. Principal coordinates and cluster analyses based on RAPD markers indicate that although K. kauaiensis has substantial genetic variation, samples are clearly separate from the other two species of the genus. In contrast, K. cookei and K. drynarioides collections are more similar, but still distinguishable when analyzed separately. The presence of substantial genetic variation lends optimism to the eventual recovery of K. kauaiensis through conservation efforts. Combinations of RAPD primers are suggested that reveal diagnostic alleles for each of the three extant species and can thus be used for species identification
POLYPOGON ELONGATUS H.B.K. (POACEAE) NEW IN TEXAS
Volume: 9Start Page: 187End Page: 18
VEGETATIVE APOMIXIS IN MUHLENBERGIA REPENS (POACEAE: ERAGROSTIDEAE)
Volume: 11Start Page: 282End Page: 28
AN ANALYSIS OF MORPHOLOGICAL VARIATION IN MUHLENBERGIA CAPILLARIS (POACEAE) AND ITS ALLIES IN THE SOUTHEASTERN UNITED STATES
Volume: 13Start Page: 303End Page: 31
MORPHOLOGICAL VARIATION AND SYNOPSIS OF THE MUHLENBERGIA REPENS COMPLEX (POACEAE)
Volume: 17Start Page: 349End Page: 36