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Showing 2 results for Tetraploid
Hossein Abdi, Hadi Alipour, Iraj Bernousi, Jafar Jafarzadeh,
Volume 10, Issue 1 (9-2023)
Abstract
Evaluating the population structure is essential for understanding diversity patterns, choosing proper parents for crossing, accurate identification of genomic regions controlling traits, and evolutionary and kinship relationship studies. In this research, the genetic structure of a wheat population was studied in a panel consisting of 383 Iranian wheat genotypes of hexaploid (cultivars and landraces) and tetraploid species based on distance-based methods (principal component analysis and discriminant analysis of principal component). For this purpose, 16270 single nucleotide polymorphism (SNP) markers obtained by the GBS technique were used. According to the results, almost a quarter of the total variance was belonged to the diversity between populations, and the Fst coefficient between cultivars and landraces was equal to 0.15. In contrast, the above coefficient between tetraploid samples and hexaploid landraces was high and equal to 0.44. Genome D had the lowest value of Fst index and chromosome 4B showed the highest Fst coefficient, and other genetic diversity indices. Although the PCA biplot distinguished hexaploid wheat cultivars from landraces, it was unable to distinctly separate tetraploid genotypes from other genotypes. Accurate evaluation of the population structure with the DAPC method was able to identify and separate the predetermined successfully groups, suggesting that the DAPC approach maximizes the differentiation between groups and minimizes the changes within the group. Partial admixture between cultivars and landraces of hexaploid wheat can be related to gene exchange between these two groups or perhaps their wrong labeling at the time of collection. In general, the results of this study provided valuable information about the genetic differentiation of Iranian tetraploid and hexaploid wheat, which can be used in future wheat breeding programs. Further, protecting these genotypes in gene banks is necessary for different strategies.
Elham Azizi, Najmeh Salehan, Raheleh Rahbarian, Ali Masoomi,
Volume 10, Issue 2 (2-2024)
Abstract
Purslane (Portulaca oleracea) is a common widely utilized medicinal plant, especially in tropical regions. To explore the cytogenetic characteristics of purslane, an experiment was conducted on five landraces of purslane, including Qom, Khoy, Kalat, Yazd and Gachsaran in Payame Noor University of Mashhad, Iran. The results showed that in all five landraces, the basic chromosomes number was x=9; two landraces (Qom and Yazd) were tetraploid (2n=4x=36) and three landraces (Gachsaran, Khoy and Kalat) were diploid (2n=2x=18). Chromosome type was meta-centric and sub-meta-centric. The landraces of Khoy and Yazd had the longest and the shortest chromosomes respectively. In all landrace, the short arm size ranged from 5.93 µm to 8.07 µm and the long arm size ranged from 9.21 µm to 10.04 µm. According to the Stebbins' Table, landrace of Qom was the member of class 1B and others were members of class 1A. This represents a similar and primary evolutionary situation between landraces. In the clustering of different landraces in terms of karyotypic traits, Khoy and Kalat landraces were placed in one cluster and each of Gachsaran, Yazd and Qom landraces were placed in separate branches. PCA showed that the first three traits as Length of Long arm, Length of short arm and Length of total chromosome explained more than 97% of the total variation among the landraces. In general, considering the medicinal properties and wide distribution of purslane, determining the ploidy level and chromosomal study of different landraces of this plant can be effective in breeding and increasing its quantitative and qualitative production.
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