Nucleolar chromosome variation and evolution in trie genusVicia

Abstract

SUMMARY -The nucleolar chromosomes in the genus Vicia usually comprise one or rarely two pairs of the complement in the diploid (2n= 10, 12, 14; x = 5, 6, 7) taxa. Barring V. anatolica nucleolar chromosomes in complements of various species have one secondary constriction and one satellite each. In V. anatolica (2n = 2x-10) one of the two nucleolar chromosome pairs contained two secondary constrictions and two satellites. The nucleolar chromosomes in Vicia species show substantial variation, in satellite size from very minute to highly conspicuous, in the location of primary and secondary constrictions from terminal to mid region, and in the size of mid arm from very small to about 90 per cent of the total chromosome size. On the basis of proportionate size of the three stainable components, the nucleolar chromosomes in Vicia species have been classified into eighteen distinct types. The comparative morphology of the nucleolar chromosomes shows that interchanges including Robert-sonian fusion, deletion and/or inversion have mainly contributed to their divergence and evolution. Overall, the nucleolar chromosome variation showed a good correlation with the taxonomic classification. The present results provide probably the first example of an astonishing array of diversity in the form and shape of nucleolar chromosomes within a genus.

Fluorescence in situ hybridization with multiple repeated DNA probes applied to the analysis of chromosomal and genomic relationship levels between faba bean (Vicia faba) and its close wild relatives

“…Because of many advantages for chromosomal related analysis, many cytogenetic phenomena were observed for the fi rst time in this species (see FUCHS et al 1998). However, information about the chromosomes, genomes and genetics of V. faba vis-à-vis its close wild relatives and other Vicia species is confl icting (RAINA and REES 1983;RAINA and BISHT 1988; Downloaded by [University of Illinois Chicago] at 15:39 13 October 2014 RAINA et al 1989;RAINA 1990RAINA , 2000see MAXTED et al 1991; VAN DE VEN et al 1993;OGIHARA 1994, 1995;BISHT et al 1998;KOUL et al 1999). Section Faba has indeed been considered to be the genus Faba but has been recently classifi ed as a section of Vicia.…”

A Karyological Study in Some Species of Coffea L. and in the Closest Relative Psilanthus travancorensis (Wight & Arn.) J.-F. Leroy

“…2). Variations in the size of the secondary constriction and/or in the satellite segment have been reported as useful criteria for species recognition and have been of great relevance for interpreting karyo-evolutionary trends as observed in Means followed by the same letter = differences were not significant at the level of 5% after Tukey test; Means followed by different letters = differences were significant at the level of 5% after Tukey test; *= data from Pierozzi et al (1999) employed for comparisons Capsicum species (Moscone et al, 1995) or as in some Vicia species (Bisht et al, 1998), for instance. No significant differences were seen among the species regarding centromeric index values.…”

Mapping of rDNA on the chromosomes of Eleusine species by fluorescence in situ hybridization.

“…Fluorescence in situ hybridization is an important technique for locating repetitive DNA sequences on chromosomes and provide valuable information on genome organization, chromosome evolution, cytotaxonomy, introgression and deletion (Mukai et al, 1990(Mukai et al, , 1991Leitch et al, 1992;Linde-Laursen et al, 1992;Kim et al, 1993;Fukui et al, 1994;Raina and Mukai, 1999). In conventional cytogenetical analysis, rDNA (only 18S-5.8S-26S) as secondary constrictions provided an important morhpological marker for comparative karyotype analysis in various species (Ved Brat, 1965;Bisht, 1992;Bisht and Raina, 1998). However, in many cases the secondary constrictions remain unresolved and especially in species with small chromosomes is very difficult.…”