Cytogenetic Analysis of Different Landraces of Purslane (Portulaca oleracea L.)

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.