Knowledge of rangewide variation in DNA content and ploidy level may be valuable in understanding the evolutionary history of a species. Recent studies of Acacia senegal report diploids and occasional tetraploids in the Sudano-Sahelian region of sub-Saharan Africa, but nothing is known about the overall extent of DNA ploidy variation within the species. In this study, we determine the DNA conte...

BACKGROUND AND AIMS One of the prerequisites for polyploid research in natural systems is knowledge of the geographical distribution of cytotypes. Here inter- and intrapopulational ploidy diversity was examined in the Gymnadenia conopsea aggregate in central Europe and potential explanations and evolutionary consequences of the observed spatial patterns investigated. METHODS DAPI flow cytomet...

Photosynthetic rates, chlorophyll content, and activities of several photosynthetic enzymes were determined per cell, per unit DNA, and per unit leaf area in five ploidal levels of the C(4) dicot Atriplex confertifolia. Volumes of bundle sheath and mesophyll protoplasts were measured in enzymatic digestions of leaf tissue. Photosynthetic rates per cell, contents of DNA per cell, and activities ...

The Spider system at the Oak Ridge National Laboratory’s Leadership Computing Facility (OLCF) is the world’s largest scale Lustre parallel file system. Envisioned as a shared parallel file system capable of delivering both the bandwidth and capacity requirements of the OLCF’s diverse computational environment, the project had a number of ambitious goals. To support the workloads of the OLCF’s d...

Cytological diploidization process is different in autopolyploid and allopolyploid species. Colchicine applied at the onset of meiosis suppresses the effect of pairing regulator genes resulting multivalents formation in bivalent-forming species. Colchicine treated maizes (4x = 2n = 20, AmAmBmBm) showed up to 5IV, suggesting pairing between chromosomes from genomes homoeologous Am and Bm. In unt...

BACKGROUND AND AIMS Apomictic plants maintain functional pollen, and via pollination the genetic factors controlling apomixis can be potentially transferred to congeneric sexual populations. In contrast, the sexual individuals do not fertilize apomictic plants which produce seeds without fertilization of the egg cells. This unidirectional introgressive hybridization is expected finally to repla...

Continued reduction in limited natural resources worldwide increasingly necessitates the incorporation of low-maintenance and low-input plant materials into urban landscapes. Some fine-leaved Festuca grass species have been used in formal gardens and native urban landscapes because of their inherent tolerance to abiotic stresses, but native, ornamental types (tall and non-spreading with multico...

Chromosome counts and karyotype information from 41 populations of 20 species and 6 varieties of Nicotianeae (Solanaceae) from South America belonging to Bouchetia Dunal (x 5 8), Fabiana Ruiz & Pav. (x 5 9), Leptoglossis Benth. (x 5 10), Nierembergia Ruiz & Pav. (x 5 8, 9), and Petunia Juss. (x 5 7, 9) are given, including first reports from 14 taxa: F. densa Rémy, N. ericoides Miers, and P. pa...

chromosome counting was performed in nine populations of achillea tenuifolia lam and eight populations of a. bieberestinii afan (asteraceae) collected from hamedan and kermanshah provinces in the west of iran. chromosome numbers in both species varied from 2n=2x=18 to 2n=4x=36. some populations of both species showed (2n=4x=36) chromosome number that is the first report as polyploidy levels. an...

coronal T2 coronal FLAIR SOS 12.8/13.6 12.5/11.4 2x 14.8/17.3 14.5/13.2 3x 19.8/24.8 14.8/12.5 4x 22.9/25.8 16.1/14.3 Table 1: SNR (reader1/reader2) coronal T2 coronal FLAIR SOS 2.9/3.0 2.7/2.9 2x 2.8/2.6 2.1/2.2 3x 2.3/2.4 1.4/1.9 4x 2.0/2.0 1.1/1.3 Table 3: average qualitative scoring (reader1/reader2); (scoring: 1-poorly defined, 2-seen, 3-well defined); (green-diagnostic quality; yellowsome...