Karyomorphological and morphometric studies of ploidy levels in some wheat (Triticum aestivum L.) genotypes

Abstract

Karyomorphological and morphometric investigations of different ploidy levels of 14 genotypes of Triticum aestivum L. and one genotype of Tritiauu durum Desf. showed that, total chromosomal length (TCL) varied between genotypes. The highest value (56.21 μm) was recorded with mean chromosomal length of 8.03 ± 0.81 μm, while the lowest value of TCL (31.65 μm) was found with mean chromosomal length (MCL) of 4.52 ± 0.41 μm. Simple Pearson correlation coefficient (r) between TCL and MCL was the highest (r = 1.0 and P = 0.000). While the correlation coefficients between mean arm ratio (MAR) and parameters: total form (TF), intra chromosomal asymmetry index (A,) and m (karyotype; metacentric region chromosome) as well as the coefficients between TF and m and between A, and m were the only significant (P<0.01) ones. Intra chromosomal asymmetry had a significant (P = 0.000) effect of total form percent than interchomosomal index. TCL and MCL were the most important karyological features influencing the principal component analysis and had 81.7 % variation, while in combination with MAR revealed 94% variation. Cluster dendrogram revealed close association and adjacent phylogcnetic relatedness of tri-and hexaploid and also tetra-and hexaploid genotypes.