Dynamics of the genetic diversity of oat varieties in the Tyumen region at avenin-coding loci

Molecular and biochemical markers are used to analyze the intraspecific genetic diversity of crops. Prolamincoding loci are highly effective for assessing this indicator. On the basis of the Laboratory of Varietal Seed Identification of the State Agrarian University of the Northern Trans-Urals, 18 varieties of common oat included in the State Register of Selection Achievements in the Tyumen Region from the 1930s to 2019 were studied by electrophoresis in 2018–2019. The aim of the work was to study the dynamics of the genetic diversity of oat va rieties at avenin-coding loci. For the analysis, 100 grains of each variety were used. Electrophoresis was carried out in vertical plates of 13.2 % polyacrylamide gel at a constant vol tage of 500 V for 4.0–4.5 h. It was found that 44.4 % of the varieties are heterogeneous, each consisting of two biotypes. For three loci, 20 alleles were identified, 10 of which were detected for the first time. The allele frequency of avenin-coding loci varied with time. In the process of variety exchange, alleles that are characteristic of varieties of non-Russian origin were replaced by alleles present in domestic varieties and then in the varieties developed by local breeding institutions. The following alleles had the highest frequency in Tyumen varieties: Avn A4(50.0 %), A2(25.0 %), Avn B4(50.0 %), Bnew6(37.5 %), Avn C1(37.5 %), C2 and C5(25.0 %). These alleles are of great value as markers of agronomically and adaptively important characters for the region in question. The amount of genetic diversity of oats varied with time from 0.33 in 1929–1950 to up to 0.75 in 2019. The high value of genetic diversity in modern breeding varieties of the Scientific Research Institute of Agriculture of the Northern Trans-Urals and an increase in this indicator over the past 20 years are associated with the use of genetically heterogeneous source material in the breeding process. This allowed obtaining varieties with high adaptive potentials in the natural climatic conditions of the region.

Morphological Identification of Lepidii Seu Descurainiae Semen and Adulterant Seeds Using Microscopic Analysis

Lepidii seu Descurainiae Semen, the dried ripe seeds of Descurainia sophia (L.) Webb ex Prantl or Lepidium apetalum Willd., is used widely as a traditional herbal medicine in Northeast Asia. However, seeds of a number of other species have been misidentified as Lepidii seu Descurainiae Semen, and are therefore misused because of morphological similarities among the seeds of these species. To accurately identify Lepidii seu Descurainiae Semen, we investigated the morphology, mucilage reaction, and micromorphology of Lepidii seu Descurainiae Semen and the seeds of other plant species. We used a stereomicroscope and a scanning electron microscope to describe and compare various morphological and micromorphological characteristics of seeds, and a light microscope to determine the presence or absence of mucilage. We evaluated the potential usefulness of mucilage as a morphological marker for seed identification. The shape, outline, and size of seeds were useful characteristics for identification. The mucilage reaction and the three types of seed ornamentation that were identified in this study were particularly valuable for seed authentication. Based on these results, we created an identification key based on morphology and micromorphology of Lepidii seu Descurainiae Semen and adulterant seeds. The method of seed identification using microscopic examination, as described here, is easy and economical, making it a potential key tool for accurate identification of Lepidii seu Descurainiae Semen and seeds of other medicinal plants.