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...

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...

meiotic study was performed in 11 brassica napus cultivars considering chiasma frequency anddistribution, chromosome pairing, as well as the occurrence of b-chromosomes and their effects on chiasmafrequency. such cytogenetic pairing, along with agronomic characteristics, may be used in planninghybridization among the b. napus cultivars. all the cultivars studied possessed n=19 chromosome number...

tea (camellia sinensis) is one of the most economically important crops and is considered tobe the national drink of iran. although there has been an intensive cytogenetic study of tea in differentregions of the world, there has been no report from iran. therefore, the present investigation was carriedout in order to present the basic cytogenetical features of various tea cultivators grown in t...

Chiasma counting has been regarded as the most straightforward method of scoring the total number of crossing-over events in the genome. In organisms in which genetic analysis is difficult or impossible to perform, it is a good estimator of the level of genetic recombination. In this paper we evaluated the chiasma frequency and distribution at diakinesis of twelve Brazilian oat varieties (Avena...

Information concerning natural variation either in chiasma frequency or in the genetic basis of any such variation is a valuable tool to characterize phenotypic traits and their genetic control. Here meiotic recombination frequencies are analysed in nine geographically and ecologically diverse accessions of Arabidopsis thaliana, and a comparative study was carried out incorporating previous dat...

A single chromosome of the grass species Festuca pratensis has been introgressed into Lolium perenne to produce a diploid monosomic substitution line 2n = 2x = 14. The chromatin of F. pratensis and L. perenne can be distinguished by genomic in situ hybridization (GISH), and it is therefore possible to visualize the substituted F. pratensis chromosome in the L. perenne background and to study ch...

Two T7OH/+ translocation-carrying male mice were used in an investigation into the relation between the segregation pattern of the translocation caused multivalent at anaphase I and the position of the only chiasma in a long interstitial segment. Moreover, the relation between meiotic stage (from early diakinesis to metaphase I) and chiasma movement was assessed. It appeared that pronounced mov...