Relevance.In recent years vegetable crop Brassica rapa ssp. chinensis var. purpuraria (synonyms: Brassica campestris L. var.purpurea Bailey; Brassica rapa L. ssp. chinensis var. purpurea) is gaining popularity as an object of genetic and molecular researches, and as an economically valuable vegetable plant due to the high content of biologically active compounds and distinctive economically valuable traits. Effective technology for development DH-plants to accelerate the breeding process for this culture has not been developed yet, so research in this area is relevant.Materials and methods. The study included two varieties from the collection of Vavilov AllRussian Research Institute of Plant Industry (VIR): No. 1301 (China) and No. 1357(Netherlands). Both protocols standard unmodified and with addition of silver nitrate (AgNO3) in the medium for embryogenesis induction were used in experiments for production of DH plants from isolated microspore in vitro. Direct chromosome counting in meristem cells and flow cytometry were used to determine the ploidy of regenerating plants.Results. As a result of the study embryogenesis in B. purpuraria culture can develop with the use of a standard protocol as well as with the addition of silver nitrate that showed a positive effect on the induction of embryogenesis. The yield of embryoids varied depending on the genotype of the individual plant within the variety accession. The highest yield of embryoids was 40 embryoids/petri dish. The main problem at the stage of regeneration is that about half of the regenerating plants occurred to be albinos and were not viable. We show a high degree of spontaneous chromosome doubling in regenerated plants (all analyzed plants were doubled haploids). In total 38 regenerated plants were obtained from accession No. 1301. It was shown that four DH-plants had self-incompatibility after self-pollination, but seed progeny from other plants was obtained. The created material was taken for genetics study and breeding work.

Haploid technologies are used to create homozygous lines for accelerated breeding. We aimed to optimize the technology for using the isolated microspore culture in vitro to obtain doubled haploids of the carrot (Daucus carota L.). We studied two carrot varieties with different responsiveness to embryogenesis, Altajskaya lakomka and Breeding line 17. Carrot microspores were isolated from buds and cultivated in liquid nutrient media supplemented with an antibiotic and activated carbon in vitro. They were exposed to different thermal treatments. The experiment showed the benefits of combining cold pre-treatment of buds (5°C for 1 day) with heat shock of isolated microspores in vitro (32°C for 2 days). The induction of embryogenesis on the NLN-13 medium was twice as high as on the MSm-13 medium. The use of 1% activated carbon in 0.5% agarose increased the yield of embryoids by more than 1.5 times. 100 mg/L of ampicillin was found to be the most efficient concentration. After 30 days of cultivation under optimized conditions, the yield was 161.3 and 44.0 embryoids per Petri dish for the cultivar Altajskaya lakomka and Breeding line 17, respectively. The induction of carrot embryogenesis is determined by the type and duration of thermal stress, the composition of the nutrient medium, the use of activated carbon as a sorbent, the addition of β-lactam antibiotics, and the type of explant exposed to thermal treatment. Our technology enabled us to obtain homozygous doubled haploid lines of carrots during a year, and these lines were included in the breeding process to create F1 hybrids.

The great economic importance of sugar beet determines the ongoing biotechnological studies conducted worldwide to improve the technology of obtaining doubled haploids (DHs) using the method of unpollinated ovule culture in vitro. To improve the induction of gynogenesis, we tested the effect of thidiazuron (TDZ), temperature bud pretreatment, different concentrations of sucrose, and culturing on liquid or solid medium. Three genotypes were tested in this study. The use of TDZ at a concentration of 0.4 mg/L in solid IMB (induction medium for Beta vulgaris) induction nutrient medium with 3 g/L phytagel, 50 g/L sucrose, 200 mg/L ampicillin and cultivation at 28◦C in the dark produced up to 16.7% induced ovules. The liquid nutrient medium of the same composition induced up to 8% ovules. Increasing TDZ concentration to 0.8 mg/L resulted in reduction or total inhibition of gynogenesis, depending on the genotype. Reducing the sucrose concentration to 20 g/L or increasing it to 80 g/L was not effective. In all three genotypes, the absence of temperature pretreatment of buds (5–6 °C) showed the best results. The plant regeneration with MS nutrient medium of 20 g/L sucrose, 3 g/L phytagel, 1 mg/L 6-benzylaminopurine (BAP) and 0.1 mg/L gibberellic acid (GA₃) resulted in up to seven shoots from one induced ovule in the most responsive genotype. We showed by flow cytometry, chromosome counting and chloroplast number assessment that all regenerant plants were haploid (2n = x = 9).

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.

The article presents the results of research on the production in vitro of regenerated plants from the seeds of cultivars of lettuce (Lactuca sativa L.) Emerald, Bouquet, Chameleon (FSBSI Federal Scientific Vegetable Center), susceptible of aspermia tomato (Tomato aspermy cucumovirus) – AsTV. Seeds of strongly susceptible to AsTV varieties of salad Chameleon and Bouquet were subjected to thermotherapy at different temperatures (37°C, 38°C, 40°C) for a different time interval (1, 3, 5, 7, 10 days) in dry form and when moistened. Marked varietal specificity during germination of seeds after thermotherapy. Thus, the greatest number of seedlings in the emerald variety was obtained after 5 days of thermotherapy (10.0±0), while the Bouquet variety had the best results after 3 days of thermotherapy (9.3±1.2) with moisture. After thermotherapy of dry seeds by 40°C plant material of cultivar Emerald was planted on solid and liquid culture media. The conditions of step sterilization of lettuce seeds for introduction into the culture in vitro were chosen: washing in 96% ethanol, then in 50% aqueous solution of "Whiteness" with the addition of Twin-20, after in sterile distilled water. The nutrient medium for germination of lettuce seeds was used: Gamborg B5 (2% sucrose, 7.0 g/l agar), and the liquid nutrient medium was of that composition. The obtained seedlings were cutted and transferred to medium MS (2% sucrose, 0.1 mg/l ha and 1 mg/l BAP, 3.0 g/l phytogel). The formed shoots for rooting were transferred to the MS medium (2% sucrose, 3.0 g/l phytogel). In the future, lettuce plants will be adapted in vivo and tested for the presence of tomato aspermia virus in the planting material.

ЛУКОВИЧНЫЕ ФОРМЫ МЕЖВИДОВЫХ ГИБРИДОВ ЛУКА, ИХ СОЗДАНИЕ И ОЦЕНКА