The gas-discharge visualization (GDV, electrophotography) method allows recording and quantifying the glow that occurs near the surface of the object (seed), when placing it in an electromagnetic field of high intensity. The hidden defects – emptiness of Pinus sibirica Du Tour seeds and biogenic damage (by phytopathogenic bacteria Pantoea ananatis) of Zea mays L. seeds were revealed and analyzed by the method of gas discharge visualization in combination with automatic analysis of digital gas-discharge images. It is shown that empty seeds have reduced values of the averaged intensity of digital gas discharge images. According to the data obtained, the methods of gas-discharge imaging (electrophotography) and microfocus radiography showed high efficiency (> 90%) of accuracy in the detection of empty seeds of Pinus sibirica. It was found that the sample of Zea mays seeds (hybrid Krasnodarskiy 194 MV) was characterized by reduced values of the average intensity of gas-discharge images, as well as the average brightness of digital X-ray images, compared with the other three seed samples. The seed sample of hybrid Krasnodarskiy 194 MB was characterized by the worst sowing qualities: emergence rate, germination, root length and shoot length. It was shown that the Krasnodarskiy 194 MB seeds were affected by phytopathogenic bacteria Pantoea ananatis. The average inverse correlations of a number of characteristics of gas-discharge glow (area, total intensity) with the standard deviation of brightness of digital X-ray images, as well as weak reliable correlation of most gas-discharge characteristics with seeding qualities were found. Comparative assessment of gas discharge indices and seedlings germination as integral indices for evaluation of biological completeness of Zea mays seeds was carried out. Research has confirmed that the method of gas discharge visualization in combination with automatic analysis of digital gas-discharge images can be used as an effective additional tool for rapid detection of defective seeds.

The Siberian dwarf pine (Pinus pumila (Pall.) Regel) has been successfully acclimatized on the northern shore of Glubokoye lake (Vyborg District of the Leningrad Region, the Russian Federation). This is the largest population (56 plants) of dwarf pine in Leningrad Region comprised of adult plants brought from the native habitat of the species. A survey of this population and statistical processing of data were carried out in comparison with the long known P. pumula population of the Scientific Experimental Station "Otradnoye" (Botanical Institute of the Russia Academy of Sciences). The dwarf pine successfully tolerates the present-day climate of the Northwest of Russia and yields full-grain seeds.

Приведены характеристики современных аппаратных решений, используемых для получения цифровых рентгеновских изображений семян. Описаны основные способы визуализации и приемы анализа цифровых рентгеновских изображений семян. Выявлены и проанализированы скрытые дефекты образцов семян исследуемых древесных лесных пород: сосны кедровой сибирской (Pinus sibirica DuTour) и сосны кедровой корейской (P. Koraiensis Siebold \& Zucc.), кукурузы сахарной (Zeamays L.), а также огурца посевного (Cucumis sativum L.) и перца овощного (Capsicum annuum L.) методом микрофокусной рентгенографии в сочетании с автоматическим анализом цифровых рентгеновских изображений. Показано, что пустозернистые и частично полнозернистые семена имеют пониженные значения показателя "Средняя яркость" рентгенограмм. Проведена сравнительная оценка рентгеновских показателей и всхожести проростков как интегральных показателей для оценки биологической полноценности семян. Ключевые слова: микрофокусная рентгенография семян, анализ изображений семян, посевные качества семян, семена древесных лесных пород, семена сельскохозяйственных культур.

Ginkgo biloba L. has been known at Peter the Great Botanic Garden of the Komarov Botanical Institute RAS (Saint-Petersburg, Russia) since 1816. In modern collection it is represented since 1947, in vegetative state. In these conditions, it forms a well-developed tree with a single trunk and a well-developed crown; the best specimens have reached a height of 15.5 m at the age of 74 years old. Compared to previously published data, its size has increased significantly. The dates of phenostages of its seasonal rhythm of development correspond to the local Calendar of Nature; it is not damaged by spring and autumn frosts. The maximum percentage of rooting from cuttings was 88,5 %.The species may be recommended for Saint-Petersburg’s city planting. Earlier there was an opinion that Leningrad (Saint-Petersburg, not Kharkov) is the northern border of Ginkgo cultivation in living form of a tree (Komarova, Zamjatnin, 1990), but nowadays, in the second decade of the XXI century, its distribution may be prolonged further up to the North.

Modern hardware solutions used to obtain digital X-ray images of seeds are characterized. The main visualization methods and techniques for analyzing digital X-ray images of seeds are described. We revealed and assessed hidden defects of seed samples of the studied species such as Siberian cedar pine ( Pinus sibirica Du Tour), Korean cedar pine ( P. koraiensis Siebold & Zucc.), sugar corn ( Zea mays L.), cucumber ( Cucumis sativum L.), and pepper ( Capsicum annuum L.) by microfocus X-ray radiography in combination with automatic analysis of digital X-ray images. Empty-grain and partially full-grain seeds have lower values of the “average brightness” of X-ray diffraction patterns. A comparative assessment of X-ray indicators and germination capacity of seedlings as integrated indicators for assessing the biological usefulness of seeds is performed.

The Dwarf Siberian Pine ( Pinus pumila (Pall.) Regel) is being grown at Peter the Great Botanic Garden of the Komarov Botanical Institute RAS at Saint-Petersburg (Russia) since the beginning of the XIX century, and it is here it was firstly introduced into general cultivation. This is highly decorative evergreen conifer, suitable both for singular and group planting and promising for alpine gardens. It is winter hardy and stands the climate of North-West Russia well. As a result of experiments of seed propagation the new method of growing this species from seeds has been elaborated with usage of the seed germination regulators without long stratification. The use of new regulators of seed germination allows to simplify the well-known methods of growing the Dwarf Siberian Pine from seeds and to enlarge the ratio and the quality of the plants grown.