The Buffelgrass (Cenchrus ciliaris L., Poaceae) is one of the most important pasturage grasses due to its high productivity and good forage qualities. This species possess a high adaptability to bioclimatic constraints of arid zones and may be used for the restoration of degraded arid ecosystems. Tunisian populations present three ploidy levels (4x, 5x and 6x) with a basic chromosome number x=9...

El tamaño del genoma de 18 especies género Carduncellus, dos los géneros relacionados, Phonus y el monotípico Femeniasia (F. balearica) ha sido medido por primera vez mediante citometría flujo. Los niveles ploidía se asignaron utilizando datos junto con recuentos cromosomas previamente reportados. Se construyó un marco filogenético para visualizar la distribución las características citogenétic...

The long term consequences of graduated interference with the acquisition of hippocampal neurons and glia during early infancy were examined with quantitative histology and 3H-thymidine autoradiography. The head region containing the hippocampus was irradiated from day two on with either two (2X), fo~r (4X), six (6X) or eight (8X) doses of 150-200r X-rays. The animals were killed at 30,60,90 an...

mdash; Plant regeneration from immature intergeneric embryos through direct callus induction was investigated in the case of hybridization between T aestivum cv Chinese Spring (2n = 6x = 42, AABBDD) and A cristatum 4x with one B chromosome (2n = 4x = 28 + 1 B, PPPP). Twenty-three abnormal immature hybrid embryos were directly cultured on MS solid medium with 2 mg / L 2,4-D to induce calli which...

Amphiploids (2n = 6x = 42) of Ae. kotschyi and Ae. biuncialis with self-compatible S. cereale were produced from F1 sterile hybrids (2n = 3x = 21) through colchicine treatment and callus tissue regeneration. The amphiploids resembled the F1 plants in overall morphology, but were larger in all respects and self-fertile. The spikelets consisted mostly of 3 well-developed florets. Selfed seeds wer...

Beginning on the second postnatal day, either two (2X group), four (4X group) or six (6X group) daily or alternate daily exposures to lowlevel X-irradiation (150-200 r) were used to interfere with the acquisition of granule cells in the olfactory bulb, hippocampus, and cerebellum of the rat. At 60 days of age, the relationship between post-irradiation recovery and permanent granule cell loss wa...

BACKGROUND AND AIMS Detailed knowledge of variations in ploidy levels and their geographic distributions is one of the key tasks faced in polyploid research in natural systems. Flow cytometry has greatly facilitated the field of cytogeography by allowing characterization of ploidy levels at both the regional and population scale, and at multiple stages of the life cycle. In the present study, f...