Karyotype analysis and new chromosome number reports in <Emphasis Type="Italic">Achillea</Emphasis> species |
| |
Authors: | Fatameh Ebrahim Hassan Pakniyat Ahmad Arzani Mehdi Rahimmalek |
| |
Institution: | 1.Department of Crop Production and Plant Breeding, College of Agriculture,Shiraz University,Shiraz,Iran;2.Department of Agronomy and Plant Breeding, College of Agriculture,Isfahan University of Technology,Isfahan,Iran |
| |
Abstract: | Cytological analyses were performed in nineteen accessions belonging to seven Achillea species. The results indicate that two species, A. filipendulina and A. tenuifolia, are diploid (2n = 2x = 18) and three species, A. bieberstinii, A. pachycephala, and A. aucheri are tetraploid (2n = 4x = 36). For two latter species, the chromosome numbers are new. Two ploidy levels of 2n = 6x = 54 and 2n = 8x = 72 in A. millefolium and two ploidy levels of 2n = 2x = 18 and 2n = 4x = 36 in A. santolina species were found. Cluster analysis based on chromosomal characteristics and karyotype asymmetry indices clustered the studied
genotypes into three major groups. The first group included the diploid species (A. filipendulina, A. santolina and A. tenufolia), while the second group comprised tetraploid species (A. santolina, A. aucheri and A. pachycephala). A. millefolium (hexaploid, octaploid) and A. bieberstinii (tetraploid) were classified in the third group. Total form percentage (TF%) in groups 1, 2 and 3 were 42.03, 42.15 and 41.08,
respectively. Group 1 possessed the highest average of symmetry index (S% = 70.8). Stebbins classification method grouped
all accessions in class A. Moreover, group 1 (diploid level species), had the most symmetric karyotype from point of view
of centromere and chromosome length. Therefore, it can be concluded that the genotypes belonging to group 1 are the earliest
evolutionary form. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|