Cytological investigations and new chromosome number reports in yarrow (Achillea millefolium Linnaeus, 1753) accessions from Iran

Abstract

In this study, a new chromosome number for Iranian yarrow (Achillea millefolium L.) accessions was reported. Cytological analyses on four Achillea millefolium accessions, indicated that two accessions were diploids (2n=2x=18) and two tetraploids (2n=4x=36). Cluster analysis based on chromosomal characteristics and karyotype asymmetry, categorized the four accessions separated into two groups. In terms of the Stebbins’ system, the karyotype of diploid accessions grouped in 2A class. The average value of the total form percentage (TF%) in the group one (diploid accessions) and two (tetraploid accessions) were 40.85 and 41.15, respectively. The group one had the highest mean value for the symmetry index (S%=57.5). Consequently, it can be inferred that diploids belonging to the group one are the earlier evolutionary forms.

A Cytogenetic, Morphological, and Ecological Comparison of Seven Different Species of Achillea.ssp. Accessions in Kurdistan Province, Iran

“…Accordingly, a range between diploid to hexaploid has been reported for Ac.aleppica species (Chehregani & Javaheri, 2014); however, all the accessions of the species were diploid in the present study. The tetraploid level was reported for A. bieberestini species (Afshari et al, 2013), which was consistent with the present results Afshari and et al, reported diploid and tetraploid levels for Ac.millefolium species (Afshari et al, 2013). In another study, Hexa and Octa-ploidy levels were reported for the species (Ebrahim et al, 2012).…”

“…Therefore, the evolution and speciation of the genus was through intra-chromosomal asymmetry rather than increasing or decreasing the chromatin content and chromosome length. The average length of each chromosome ranged from 2.93 to 3.55 microns for the species, which was consistent with other reports (Afshari et al, 2013;Sahin et al, 2006). Meanwhile, the chromosome length range was higher in certain reports than that in the results of the present study, and longer chromosomes were reported for the species (Aksu et al, 2013).…”

“…There were TA3, TA1, VE3, and TE4 in the second zone, and also TE (1, 2), BI2, MI3 VE (1, 2), and TA (2, 4) species in the third zone. Eventually, there were BI (1, 4), MI (1, 2, 4), and WI (2,4) in the fourth zone. Three groups, AL, MI, and WI were separated from the other species in the analysis, and the cytogenetic variables could not separate other species from each other.…”

“…The more the color inclined to red and the larger the size of each dot was, the greater its participation in the data variance would be. In the third zone, there were species TE (1,2,3,4), AL (2, 3), TA3, and WI3. There were also species BI (1, 2, 3, 4), AL (1,4), and TA1 in the fourth zone.…”

“…Millefolium species have shown different levels of ploidies (2x, 4x, 6x and 8x) with 2A symmetrical Stebbins index (Afshari et al, 2013). Meanwhile, study of nine populations biebersteinii species demonstrated a diploid (2x); however, chromosomal interspecies variation has been observed and there has been a symmetrical Stebbins's index 1A and 2A (Chehregani Rad et al, 2017).…”