Karyology and Genome Size Analyses of Iranian Endemic Pimpinella (Apiaceae) Species

Abstract

Pimpinella species are annual, biennial, and perennial semibushy aromatic plants cultivated for folk medicine, pharmaceuticals, food, and spices. The karyology and genome size of 17 populations of 16 different Pimpinella species collected from different locations in Iran were analyzed for inter-specific karyotypic and genome size variations. For karyological studies, root tips were squashed and painted with a DAPI solution (1 mg/ml). For flow cytometric measurements, fresh leaves of the standard reference (Solanum lycopersicum cv. Stupick, 2C DNA = 1.96 pg) and the Pimpinella samples were stained with propidium iodide. We identified two ploidy levels: diploid (2x) and tetraploid (4x), as well as five metaphase chromosomal counts of 18, 20, 22, 24, and 40. 2n = 24 is reported for the first time in the Pimpinella genus, and the presence of a B-chromosome is reported for one species. The nuclear DNA content ranged from 2C = 2.48 to 2C = 5.50 pg, along with a wide range of genome sizes between 1212.72 and 2689.50 Mbp. The average monoploid genome size and the average value of 2C DNA/chromosome were not proportional to ploidy. There were considerable positive correlations between 2C DNA and total chromatin length and total chromosomal volume. The present study results enable us to classify the genus Pimpinella with a high degree of morphological variation in Iran. In addition, cytological studies demonstrate karyotypic differences between P. anthriscoides and other species of Pimpinella, which may be utilized as a novel identification key to affiliate into a distinct, new genus – Pseudopimpinella.

Distribution, frequency and molecular basis of clethodim and quizalofop resistance in brome grass (Bromus diandrus)

“…Seeds of the resistant population 172‐20 were germinated at 25 °C in the dark on moistened filter paper for 6–7 days. Actively growing root tips of ~10–20 mm were excised, pretreated with 2 m m 8‐hydroxyquinoline for 4 h to accumulate metaphase cells, fixed in freshly prepared ethanol/glacial acetic acid (3:1) for 30 h, and finally stored at −20 °C in the same solution until use 28 . Chromosome preparations from root tip cells were performed according to Mehravi et al 29 .…”

“…Actively growing root tips of ∼10-20 mm were excised, pretreated with 2 mM 8-hydroxyquinoline for 4 h to accumulate metaphase cells, fixed in freshly prepared ethanol/glacial acetic acid (3:1) for 30 h, and finally stored at −20 °C in the same solution until use. 28 Chromosome preparations from root tip cells were performed according to Mehravi et al 29 Briefly, root tips were washed twice in ice-cold water and then twice in citrate buffer (0.01 M citric acid, 0.01 M sodium citrate, pH 4.8), and the meristematic portion of the root tips (1-1.5 mm from the apical end) were digested with 30 mL of enzyme solution (1% pectolyase, 0.7% cellulase, 0.7% cellulase R10, 1% cytohelicase in citrate buffer) for 1 h at 37 °C. Meristems were then washed twice in citrate buffer and once in ethanol, and placed in 70 mL glacial acetic acid/methanol (9:1).…”

Unveiling the epigenetic landscape of plants using flow cytometry approach

“…To make data less dimensional, a statistical method called PCA can be utilized to investigate the most pronounced variance in the (co)expression of all markers in all cells. Data patterns that are not immediately obvious from the raw data can be found using PCA [105, 106].…”