Background: Nuclear DNA content in plants is commonly estimated using flow cytometry (FCM). Plant material suitable for FCM measurement should contain the majority of its cells arrested in the G₀/G₁ phase of the cell cycle. Usually young, rapidly growing leaves are used for analysis. However, in some cases seeds would be more convenient because they can be easily transported and analyzed without the delays and additional costs required to raise seedlings. Using seeds would be particularly suitable for species that contain leaf cytosol compounds affecting fluorochrome accessibility to the DNA. Therefore, the usefulness of seeds or their specific tissues for FCM genome size estimation was investigated, and the results are presented here.Methods: The genome size of six plant species was determined by FCM using intercalating fluorochrome propidium iodide for staining isolated nuclei. Young leaves and different seed tissues were used as experimental material. Pisum sativum cv. Set (2C = 9.11 pg) was used as an internal standard. For isolation of nuclei from species containing compounds that interfere with propidium iodide intercalation and/or fluorescence, buffers were used supplemented with reductants.Results: For Anethum graveolens, Beta vulgaris, and Zea mays, cytometrically estimated genome size was the same in seeds and leaves. For Helianthus annuus, different values for DNA amounts in seeds and in leaves were obtained when using all but one of four nuclei isolation buffers. For Brassica napus var. oleifera, none of the applied nuclei isolation buffers eliminated differences in genome size determined in the seeds and leaves.Conclusions: The genome size of species that do not contain compounds that influence fluorochrome accessibility appears to be the same when estimated using specific seed tissues and young leaves. Seeds can be more suitable than leaves, especially for species containing staining inhibitors in the leaf cytosol. Thus, use of seeds for FCM nuclear DNA content estimation is recommended, although for some species a specific seed tissue (usually the radicle) should be used. Protocols for preparation of samples from endospermic and endospermless seeds have been developed.

Background: Polyploid specimens are usually characterized by greater exuberance: they reach larger sizes and/or have a larger number of some organs.Festuca amethystinaL. belongs to the sectionAulaxyper. Based on morphological features, four subspecies ofF. amethystinahave been already identified. On the other hand, it has two cytotypes: diploid and tetraploid. The main aim of our study was to distinguish morphological differences between the cytotypes ofF. amethystina, assuming that its phenotype differs significantly.Methods: The nuclear DNA content was measured by flow cytometry in dry leaves from specimens originating from 13 populations of F. amethystina. Several macrometric and micrometric traits of stems, spikelets and leaf blades were taken into account in the comparative analysis of two cytotypes.Results: In the case of cytotypes, specimens of tetraploids were larger than diploids. The conducted morphometric analysis of leaf cross-sections showed significant differences between the cytotypes.Discussion: The research has confirmed for the first time that in the case ofF. amethystinathe principle of greater exuberance of polyploids is true. Differences between the cytotypes are statistically significant, however, they are not enough to make easy the distinction of cytotypes on the basis of the measurements themselves. Our findings favor the rule known inFestucataxonomy as a whole, i.e. that the ploidy level can be one of the main classification criteria.

This study aimed to analyze the effect of various mutagens on the in vitro development, physiological activity, acclimatization efficiency, and genetic integrity of Lamprocapnos spectabilis ‘Valentine’. Gold nanoparticles (AuNPs), microwaves, and X-rays were used at different doses. The profiles of primary and secondary metabolites and the enzymatic activity in the produced plants were studied. The usefulness of various genetic markers in the detection of mutations in the species was compared. The genome size of L. spectabilis was estimated for the first time. It was found that the addition of AuNPs into the culture medium had a positive impact on the in vitro development and multiplication of plants. All of the shoots regenerated adventitious roots, but plants subjected to the longest microwave irradiation (3 × 9 s) and the non-treated control had the lowest acclimatization efficiency. Application of mutagens significantly affected the activity and profile of most enzymes and phytochemicals studied, however, the final effect depended on the agent type and dose. Mutations were detected by DAMD, RAPD, and SCoT markers in 7.5% of plants, but not by ISSRs. Phenotype variation in leaf shape was found in four plants. The genome size of L. spectabilis was found to be very small; about 1281 Mbp.