Fusarium wilt pathogens represent an ongoing threat to pepper production worldwide. This is the first report providing data on the molecular identification of Fusarium fungi that cause wilt in pepper in the southern regions of Russia. Monitoring of the Fusarium infection on pepper was carried out in 2019–2022 in two economically important regions of this culture production: the Krasnodar Krai and Crimea. Based on a phylogenetic analysis of the translation elongation factor (EF1a) and the internal transcribed spacer (ITS), as well as the macro- and micromorphological characteristics of the fungi, the causative agents of Fusarium wilt have been identified. The causative agents identified as representatives of the Fusarium species composition included: F. clavus, F. solani, F. oxysporum, F. verticillioides, F. commune, F. torulosum, and F. sporotrichioides. Depending on the region, the specifics of biodiversity and the ratio of these species in pathocomplexes were noted. In Crimea, wilting could be attributed to all of the identified species; in the Krasnodar Krai, F. verticillioides and F. clavus were found to contribute to wilting. The pathogenicity test showed that the pathogens of pepper wilting in Russia, in addition to the already known F. oxysporum and F. solani, are the species F. clavus and F. verticillioides. This is the first report on the ability of these species to cause Fusarium wilt in pepper cultures. The obtained data will be of practical value for the development of biological control measures for fungi of the genus Fusarium, which cause pepper wilt in areas of industrial production and seed production. In addition, data on species composition and aggressive isolates will be used in a pepper breeding program for resistance to Fusarium wilt.
Fusarium basal rot of onions causes large losses during storage of commercial production of onion bulbs, which in turn adversely affects the food market situation in the off-season period. There are no data on the composition of Fusarium spp., which causes onion basal rot in the Russian Federation. Therefore, our research was aimed at Fusarium spp. causing onion basal rot in the Moscow Region of the Russian Federation and studying the pathogenicity of these species for the host plant. We studied 20 isolates of Fusarium spp. collected from affected mature bulbs and seed bulbs. Species identification of the isolates was carried out using analysis of the nucleotide sequences of the three genetic loci ITS, tef1 and rpb2, as well as was based on the macro- and micromorphological characteristics of these isolates. As a result, the species F. annulatum (F. fujikuroi species complex), F. oxysporum (F. oxysporum species complex), F. acuminatum (F. tricinctum species complex) and F. solani (F. solani species complex) were identified to involve in the pathogenesis of Fusarium basal rot. We have shown for the first time that the species F. annulatum and F. acuminatum are highly aggressive and capable of causing onion basal rot. The predominant species were F. annulatum and F. oxysporum. The proportion of these species in the total number of analyzed isolates was 60% and 25%, respectively. The largest proportion (33%) of highly aggressive on mature bulbs isolates was found in the species F. annulatum. The data obtained provide practical insights for developing strategies to manage Fusarium fungi responsible for onion basal rot Moscow Region of the Russian Federation. In addition, data about species composition and aggressive isolates may be used in onion breeding for resistance to Fusarium basal rot.
Isolated microspore culture in vitro (IMC) is an advanced technique for producing doubled haploids. We developed a modified microspore isolation method for the Brassicaceae family, which exceeds the results obtained by a standard microspore isolation method. We found that the new method allows an increase in the percentage of microspores at the embryogenic stage of development in the culture. In the spring rapeseed ‘Ratnik’ culture the percentage of microspores increases from 66.7% to 73%, and in the European radish ‘RBK’ from 34% to 61.9%. Moreover, the new method of microspore isolation made it possible to expand the range of linear bud sizes (from 3.5–4.0 to 3.0–4.5 mm for spring rapeseed ‘Ratnik’) suitable for IMC technology. In addition, the new method of microspore isolation reduced the debris in the preparation of spring rapeseed ‘Ratnik’ and European radish ‘RBK’ by 2.4 and 15 times, respectively. The best results were shown on Sareptian mustard No. 72, where the yield of embryoids increased by 7.5 times. Remarkably, the new method of microspore isolation allowed us to obtain the first embryoids of red cabbage No. 428, whereas no embryoids were obtained using the standard method of microspore isolation. In summary, the new method of microspore isolation allows an increase in the efficiency of IMC technology for Brassicaceae family crops.
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.
Relevance. Doubled haploids (DH-plants) are excellent material for genetic research and breeding due to their complete homozygosity. The genus Raphanus from the Brassicaceae family is the toughest to produce doubled haploid plants through isolated microspore culture in vitro (IMC). The study of the causes of disturbed root formation and the development of elements of this stage of technology will significantly increase the effectiveness of the IMC technology for European radish.Methods. The study included three varieties from the collection of the Federal State Budgetary Scientific Institution Federal Scientific Vegetable Center (FSBSI FSVC): Teplichny Gribovsky, Rozovo-krasniy s belim konchikom and Rhodes. The experiments used a standard protocol for obtaining DH plants using IMC technology in a standard form and with a modification of the rooting stage. The solid MS medium (with agar 7g/L): MS without hormones, MS medium supplemented with IAA at concentrations of 0.5; 1 and 2 mg / L and liquid MSm medium supplemented with 0.1 mg / L kinetin were used for rooting of regenerated plants. All media were supplemented with 20 g/L sucrose. We used three types of techniques for transplanting plant explants onto a solid hormonefree MS medium: planting micro-shoots with their basal part immersed by 2-3 mm into the medium; planting in a well made in a nutrient medium using tweezers under sterile conditions; and landing on the surface of the medium without embedment.Results. In this work, we studied the features of the stage of rooting of regenerated European radish plants in vitro conditions. The transplant technique has been proven to be important for the successful establishment of radish micro-shoots. Plant explants must be planted strictly on the surface of a solid hormone-free nutrient medium MS, without embedment. The use of tubes with bridges made of filter paper and MSm liquid medium with the addition of 0.1 mg/L kinetin for the induction of root formation also showed high efficiency. For plants prone to the formation of root-like structures (RLS) with secondary tumors (ST), multiple dissection of abnormal formations with successive transplants is necessary. Modification at the rooting stage of micro-shoots growing has increased the percentage of successfully adapted DH plants in vivo conditions from 0-14% to 95-98%.
The regular inclusion of green vegetables in the diet is beneficial to human. In Russia the main time manufacture and consumption of fresh vegetable production falls in the June-October. Seasonality of consumption of vegetables may lower the conveyor production using secure ground, as well as the introduction of a larger number of species in the production of vegetable crops. One of the priority directions of the development of greenhouse vegetable production is the introduction of hydroponic technologies, including longline. In Federal Scientific Vegetable Center has passed the test of cultivars of lettuce, rocket salad, mustard leaf and watercress breeding laboratory of green and spicy taste cultures on multi-level narrow column hydroponics (MUG). It is shown that when grown on the installation of MUG, it is possible to obtain ecologically safe and valuable spicyflavoring and salad green products. The studied varieties are looking not only for growing hydroponic salad lines, but for multi-level narrow column hydroponics (vertical vegetable growing) during the off-season. The studied varieties are promising not only for growing on hydroponic salad lines, but for multi-level narrow column hydroponics (vertical vegetable growing) during the off-season.