Genomic in situ hybridization (GISH) was used for a chromosomal composition study of the later generations of interspecific hybrids between A. cepa L. and A. fistulosum L., which are relatively resistant to downy mildew (peronosporosis). GISH revealed that F₂ hybrids, which did not produce seeds, were triploids (2n = 3x = 24) with 24 chromosomes and possessed in their complements 16 chromosomes of A. fistulosum L. and eight chromosomes of A. cepa L. or eight chromosomes of A. fistulosum L. and 16 chromosomes of A. cepa L. The advanced F₅ hybrid, which produced few seeds, was amphidiploid with 32 chromosomes. BC₁F₅ hybrid was triploid with eight chromosomes of A. fistulosum L. and 16 chromosomes of A. cepa L., which did not produce seeds. BC₂ (BC₁F₅) plant was amphidiploid that possessed 4 recombinant chromosomes and produced few seeds. GISH results point to 2n-gametes formation in macro- and microsporogenesis of the hybrids. The mechanism of 2n-gametes formation and the possibility of apomixes events in the backcrossing progeny are discussed.

High-resolution melting (HRM) analysis is a powerful detection method for fast, high-throughput post-PCR analysis. A two-step HRM marker system was developed for identification of the N-, S-, R- and T-cytoplasms of onion. In the first step for the identification of N-, S- and R-cytoplasms, one forward primer was designed to the identical sequences of both cox1 and orf725 genes, and two reverse primers specific to the polymorphic sequences of cox1 and orf725 genes were used. For the second step, breeding lines with N-cytoplasm were evaluated with primers developed from the orfA501 sequence to distinguish between N- and T-cytoplasms. An amplicon with primers to the mitocondrial atp9 gene was used as an internal control. The two-step HRM marker system was tested using 246 onion plants. HRM analysis showed that the most common source of CMS, often used by Russian breeders, was S-cytoplasm; the rarest type of CMS was R-cytoplasm; and the proportion of T-cytoplasm among the analyzed breeding lines was 20.5%. The identification of the cytoplasm of a single plant by phenotype takes from 4 to 8 years. The HRM-based system enables quick and easy distinguishing of the four types of onion cytoplasm.

The ‘edge’ effect is considered one of the fundamental ecological phenomena essential for maintaining ecosystem integrity. The properties of plant outer tissues (root, tuber, bulb and fruit peel, tree and shrub bark, leaf and stem trichomes) mimic to a great extent the ‘edge’ effect properties of different ecosystems, which suggests the possibility of the ‘edge’ effect being applicable to individual plant organisms. The most important characteristics of plant border tissues are intensive oxidant stress, high variability and biodiversity of protection mechanisms and high adsorption capacity. Wide variations in morphological, biochemical and mineral components of border tissues play an important role in the characteristics of plant adaptability values, storage duration of roots, fruit, tubers and bulbs, and the diversity of outer tissue practical application. The significance of outer tissue antioxidant status and the accumulation of polyphenols, essential oil, lipids and minerals, and the artificial improvement of such accumulation is described in connection with plant tolerance to unfavorable environmental conditions. Methods of plant ‘edge’ effect utilization in agricultural crop breeding, production of specific preparations with powerful antioxidant value and green nanoparticle synthesis of different elements have been developed. Extending the ‘edge’ effect phenomenon from ecosystems to individual organisms is of fundamental importance in agriculture, pharmacology, food industry and wastewater treatment processes.

Дикорастущие виды рода Allium L. являются источниками не только устойчивости к биотическим (болезням, вредителям) и абиотическим факторам окружающей среды (морозо-, зимостойкость, засухоустойчивость), но также отличаются по биохимическим показателям от культурного вида лука. Проведение скрещиваний с участием дикорастущих видов лука может увеличить содержание биохимических веществ у гибридов в сравнении с культурными. Во ВНИИССОК проводили скрещивания между дикорастущими и культурными видами рода Allium L. Для создания исходных форм для селекции с более высоким содержанием ценных биохимических веществ. Изучали растения межвидовых гибридов лука F₁ в комбинации скрещивания A. cepa x A. nutans и растения родительских видов: Allium cepa L. (сорта лука репчатого – Штутгартер ризен, Стригуновский) и Allium nutans L. В работе представлена морфологическая характеристика растений межвидовых гибридов лука F₁ Allium сера x Allium nutans и дана биохимическая оценка межвидовых гибридов лука. У растений определяли содержание NO³-, К+, аскорбиновой кислоты, сухого вещества, суммарного содержания водорастворимых антиоксидантов. Повышенное содержание NO³-наблюдалось у №13 F₁ A. cepa x A. nutans в сравнении с другими вариантами и стандартом. У №15 F₁ A. cepa x A. nutans содержание K+ в листьях значительно превышало накопление этих элементов у растений других вариантов. Содержание аскорбиновой кислоты у всех гибридов A. cepa x A. nutans было меньшим, по сравнению с контролем в два-три раза и варьировало от 15,8 до 28,6 мг%. Все гибридные растения также уступали растениям стандарта по содержанию сухого вещества (9,3-11,7%, в стандарте – 12,7%). Самыми низким содержанием антиоксидантов характеризовался образец №3 – 15,3 мг/г (ЕАК), самые высокие значения были получены в варианте №16 – 37,3 мг/г (ЕАК), превосходящие стандарт в два раза. У полученных растений F₁ A. cepa x A. nutans через индивидуальный отбор целесообразно направленно отбирать формы, лучшие по биохимическому составу.

Flooding is an important factor, decreasing Allium cepa bulb yield and quality. A comparison, in terms of biometrical and biochemical parameters, of five Allium cepa cultivars, grown at two different locations, characterized by contrasting conditions of water availability, i.e., precipitation excess at the end (A) or at the beginning (B) of plant growth, revealed a significant decrease in bulb weight, height, and diameter, and an increase in oxidative stress parameters, such as total antioxidant activity and polyphenol content, monosaccharides, proline, malonic dialdehyde in the condition of excessive soil humidity at the end of the vegetation period (A). Among the five cultivars studied (Zolotnichok, Zolotie cupola, Black prince, Globus, and Myachkovsky), the lowest variations of the above parameters under precipitation excess at cycle end or beginning were recorded in Zolotnichok and Zolotie cupola, which was in accordance with their high adaptability. Cultivar Myachkovsky showed the highest differences of the parameters examined between A and B conditions. Outer scale biochemical parameters demonstrated the highest stability in both regions. The participation of proline, monosaccharides, total polyphenols, and total antioxidant activity in plant defense against hypoxia, caused by waterlogging, was proved by high correlation coefficients between inner scale parameters (‘r’ from +0.714 to +0.920) and the latter with bulb yield (‘r’ from −0.745 to −0.924). High adaptability cultivars (Zolotie cupola, Zolotnichok, Black prince) showed significantly lower MDA inner/outer scales ratio and lipids outer/inner scales ratio compared to cultivars with moderate adaptability in (B) conditions. The results provide important information regarding biochemical peculiarities of Allium cepa in diverse soil humidity, which should be considered in future breeding activities of onion genotypes, characterized by high adaptability to different water excess conditions.