Cytogenetic
Sadegh Imani; Rahele Rahbarian; Ali Masoumi; Saeed Khavari Khorasani
Volume 4, Issue 7 , December 2015, , Pages 25-34
Abstract
Cytogenetical studies and karyotypes can be used for many purposes such as , to study chromosomal characteristics, identifying diploid and poly ploid species and hybridization process , to study of genetic diversity and finding taxonomic relationships, and to gather information about past evolutionary ...
Read More
Cytogenetical studies and karyotypes can be used for many purposes such as , to study chromosomal characteristics, identifying diploid and poly ploid species and hybridization process , to study of genetic diversity and finding taxonomic relationships, and to gather information about past evolutionary events. In this study, 8 ecotypes of Cichorium intybus L. Included Karaj, Taft, Khomein, Talesh, Semirom, Mollasani and Baft investigated based on cytogenetic characteristics. Results showed that all the studied ecotypes are diploid (2n=2x=18). But the length of the chromosomes is very diverse (from 0.97 to 5.56 µm for the short arm and from 1.02 to 7.14 µm for the long arm). There was no satellite in all chromosomes. In classifying based on cluster analysis method, Baft and Talesh ecotypes were in a same cluster and Tafresh and khomein ecotypes were in another cluster. Also Taft, Semirom and Mollasani ecotypes were in the third cluster. Because of the differences and diversity of traits, is expected that different clusters show more heterosis in crosses and it can be used in breeding programs. According to stebbins table, Tafresh and khomain ecotypes were in 1A class and other ecotypes were in 2B class.
Cytogenetic
Mehran Gholami; Masoomeh Jamalomidi; Koorosh Falakro
Volume 3, Issue 4 , September 2013, , Pages 87-97
Abstract
Tea (Camellia sinensis L.) is an important beverage crops containing caffeine worldwide. Releasing cultivars with high yield and quality demands knowledge about tea genetics and cytogenetics. Karyotypical study of nine tea genotypes was carried out using squash method on root tips. The best microscopic ...
Read More
Tea (Camellia sinensis L.) is an important beverage crops containing caffeine worldwide. Releasing cultivars with high yield and quality demands knowledge about tea genetics and cytogenetics. Karyotypical study of nine tea genotypes was carried out using squash method on root tips. The best microscopic slides was first obtained using root tip of tea cuttings pretreated by α-bromo Naphthaline for 8 h, fixed by farmer solution and then stained with hematoxilin. Eight morphological traits were taken into consideration, each within three meiotic chromosomes using Micromeasure software. Analysis of variance showed significant differences (1%) among genotypes, chromosomes and the interactions, for all of the measured parameters. All studied teas were diploid and had 2n=2X=30 metacenteric and submetacenteric chromosomes. Total length of chromosomes ranged from 1.10 to 4.42 μm. Also, in terms of total length of chromosomes, genotypes 4 and 8 had the highest correlation and genotypes 2 and 9 had the lowest. Moreover some cytogenetic statistics was used in order estimate the karyotypic symmetry of genotypes. The results obtained showed that the genotypes 1 and 2 had the most asymmetric and genotypes 3 and 8 had the most symmetric, based on the TF%. Ordination based on principal components analysis (PCA) revealed presented that more than 97% of total diversity with two components was described. Centromeric index and long arm length had the most roles in the components, respectively. Cluster analysis using UPGMA method, also grouped the genotypes in four clusters and 100 promising clones were separated from the others, similar to result of PCA Bi-plot, relatively.
Molecular Plant Breeding
Farangis Ghanavati; Hassan Eskandari; Gholamreza Bakhshi Khaniki
Volume 1, Issue 1 , March 2012, , Pages 85-95
Abstract
Fourteen populations of Sections Hymenobrychis, Lophobrychis and Onobrychis of sainfoin were collected from natural habitats across Iran. Number and size of chromosomes as well as karyotypic formula of the populations were measured and studied using their root tip meristemes. The basic chromosome number ...
Read More
Fourteen populations of Sections Hymenobrychis, Lophobrychis and Onobrychis of sainfoin were collected from natural habitats across Iran. Number and size of chromosomes as well as karyotypic formula of the populations were measured and studied using their root tip meristemes. The basic chromosome number varied between x=7 and x=8 and their chromosomal types were metacentric and sub-metacentric. According to average of genoms length, the highest belonged to O. viciaefolia (48.157µm) and the lowest to O. amoana subsp. meshhedensis (14.409µm). The results of analysis of variance based on unbalanced completely randomized design showed significant differences among the populations for the most of the studied traits (P<%1). O. michauxii2 classified as asymmetric class of B and others as A. O. amoena subsp. meshhedensis with 14m formula, stand in A class, had the most relative length of shortest chromosome(68.26), lowest intra chromosal asymmetrical(0.12) lowest differences of relative length(5.31) and the highest total form percentage was symmetrical species. Using principal components analysis, the first two components justified %97.94 of total variance. By cutting dendrogram, resulted from cluster analysis based on the karyptipic parameters species, the highest distance was obtained between O. schahuensis 1 and O. viciaefolia and the lowest metric distance value was obtained between populations of O. schahuensis 1 and O. chorassanica 1.
