Chromosome, ploidy analysis, and flow cytometric genome size of caper (Capparis spinosa) medicinal plant

Caper (Capparis spinosa) is a shrubby, deciduous perennial medicinal plant belonging to the Capparaceae family. Its use is in folk medicine, pharmacy, food, and spices. Chromosome, ploidy analysis, and flow cytometric genome size of 10 populations collected from different parts of Iran were analyzed. The results showed that all populations were diploid, with nine populations having 2n = 2x = 30 (P1-P8, P10) and one population having 2n = 2x = 34 (P9) chromosomes. The average chromosome length (CL) for these two chromosome groups was 1.05 and 0.97 μm, respectively. The mean monoploid genome sizes for the populations with 30 and 34 chromosomes were 0.646 and 0.633 pg, respectively. As a whole, the mean genome size of all populations was 0.643 pg. The chromosome number as well as the genome size are being reported for the first time. Cluster analysis and principal component analysis revealed a categorization of the caper population into four distinct groups. The first group comprised three populations (P1, P3, and P4), while the second group included only P2 population, the third group was represented by two populations (P5 and P7), and the fourth group encompassed four populations (P6, P8, P9, and P10). Future research on the genetic traits and breeding methodologies of this species can build upon the foundational findings of this study.