About 10-15% of the males and females of the grasshopper Melanoplus femur-rubrum collected near Rochester, New York, possessed a supernumerary B chromosome. The frequency of the B chromosome remained fairly constant during the years 1971-1974. The B chromosome was shown previously to be transmitted at a rate of about 0.5 and 0.8 by 1B males and females, respectively. This study was designed to ...

A cytogenetical study on 13 alfalfa (Medicago sativa) cultivars available in Iranian Forest and Rangelands Genebank was performed in order to obtain basic information on the variability in chiasma frequency/distribution, chromosome association and segregation. Such cytogenetic information is useful for planning hybridization programs. Cluster analysis of meiotic data and ordination of cultivars...

The centromere of chromosomes 1, 6 and 9 are physically mapped by the hypoploids of the six most proximal B-A translocations. The hypoploids are deficient for a paternal chromosome arm and, as a result, lose the paternal signal of those RFLP markers located on the missing chromosome arm. Of those markers missing from the hypoploids, the two most proximal ones on each arm of a chromosome define ...

The B chromosome of maize has been used in a study of dicentric chromosomes. TB-9Sb is a translocation between the B and chromosome 9. The B-9 of TB-9Sb carries 60% of the short arm of 9. For construction of dicentrics, a modified B-9 chromosome was used, B-9-Dp9. It consists of the B-9 chromosome plus a duplicated 9S region attached to the distal end. In meiosis, fold-back pairing and crossing...

Chromosome numbers and 2C-values of six Byblis species were determined to investigate the chromosome differentiation genome diversity in this genus. Somatic B. liniflora complex showed diploid tetraploid 2n=16 32. In contrast, number gigantea, which belongs gigantea complex, displayed only 2n=36. The 2C DNA contents across all studied over a three-fold range, from lowest value 2C=0.64 pg rorida...

To trace the interrelationships and for identification and characterisation of diversity among three species of medicinally important plant Bauhinia viz. B. acuminata B. purpurea and B. racemosa, belonging to subfamily Caesalpiniaceae, cytological study with respect to chromosome number, somatic chromosome length of component arms of chromosome, T. F% and chromosome type and seed protein variat...

We conducted a cytogenetic study of sexual lines of Boechera stricta and Boechera holboellii (2n = 14) and seven diploid apomictic accessions of their interspecific hybrid Boechera divaricarpa and B. holboellii (2n = 14 or 15). By studying chromosome morphology, rDNA repeats, genome painting, male meiosis, pollen morphology, and flow-cytometry seed screens, we revealed an unexpected plethora of...

We sampled 11 natural populations of the grasshopper Xyleus discoideus angulatus in Northeastern Brazil to analyze B chromosome frequency and meiotic behavior. We observed a single large B chromosome, resembling the X chromosome, in 29 of the 402 specimens. Eight of the 11 populations had B chromosomes, with a rather broad geographical distribution, suggesting that this is an ancient polymorphi...