Diseases of cereals caused by pathogenic fungi can significantly reduce crop yields. Many cultures are exposed to them. The disease is difficult to control on a large scale; thus, one of the relevant approaches is the crop field monitoring, which helps to identify the disease at an early stage and take measures to prevent its spread. One of the effective control methods is disease identification based on the analysis of digital images, with the possibility of obtaining them in field conditions, using mobile devices. In this work, we propose a method for the recognition of five fungal diseases of wheat shoots (leaf rust, stem rust, yellow rust, powdery mildew, and septoria), both separately and in case of multiple diseases, with the possibility of identifying the stage of plant development. A set of 2414 images of wheat fungi diseases (WFD2020) was generated, for which expert labeling was performed by the type of disease. More than 80% of the images in the dataset correspond to single disease labels (including seedlings), more than 12% are represented by healthy plants, and 6% of the images labeled are represented by multiple diseases. In the process of creating this set, a method was applied to reduce the degeneracy of the training data based on the image hashing algorithm. The disease-recognition algorithm is based on the convolutional neural network with the EfficientNet architecture. The best accuracy (0.942) was shown by a network with a training strategy based on augmentation and transfer of image styles. The recognition method was implemented as a bot on the Telegram platform, which allows users to assess plants by lesions in the field conditions.
27 December 2019 in Chemistry of plant raw material
Among the many diseases of spring wheat caused by pathogenic fungi, loose smut Ustilago tritici (Pers.) Jens. remains to be a dangerous disease with a wide range of distribution. In fields where there is no control over the emergence and spread of the disease, the yield reduction can be up to 10 %, and in the case of highly susceptible varieties, up to 40–50 %. Taking into account the increasing cost of seed protectants and their environmental damage, the cultivation of varieties resistant to loose smut is still the most affordable way to protect plants, reducing the pesticide load on agrocenoses. The crucial point in breeding for resistance is the use of resistant varieties as parental forms. The aim of our research was to isolate samples of spring wheat that are immune to loose smut against the background of artificial infection of plants with a population specific to the West Siberian region. The article presents the results of long-lasting studies of 350 genotypes of spring wheat of different ecological and geographical origin for resistance to disease. Physiological specialization of races was carried out on the basis of a differentiating set consisting of six varieties of soft wheat and three varieties of durum spring wheat. The obtained results in combination with literature data reveal changes in the racial composition of the pathogen population over the past 30–35 years. Varieties of foreign and domestic selection resistant to the West Siberian population of loose smut have been identified. Based on the analysis of pedigree samples, highly and practically resistant to loose smut, we concluded that in breeding for immunity to U. tritici, the same sources of resistance genes are most often used. Among the gene pool of spring wheat of foreign selection, the largest number of genotypes resistant to loose smut is assigned to the countries of the North American geographical zone (USA, Canada, Mexico). These are largely samples containing Ut1 genes, genes from spring wheat ‘Thatcher’ and its sister line ‘DC II-21-44’. Resistance genes in Russian wheat varieties can be traced from cultivars Beloturka, Poltavka, Selivanovsky Hare (using Saratovskaya 29 and its derivatives), and genes from wheatgrass lines AGIS 1 and Grecum 114.
Anther culture is the most effective and not technically complex tool for obtaining double wheat haploids. The current study is devoted to the research of the influence of the genotype and concentration of the growth regulator 2.4-D on the efficiency of androgenesis in vitro of spring bread wheat. The purpose of the study was to estimate the efficiency of the anther culture of hybrids of the first and second generation and their parental varieties and to study its dependence on different concentrations of the growth regulator 2.4-D. There has been carried out the estimation of the traits of the F1hybrids, the F2population, and the parental varieties ‘Obskaya 2’ and ‘Novosibirskaya 15’ when 2.4-D was added to the induction medium at a concentration of 1 and 2 mg/l. There has been established that the F2population and the parental variety ‘Novosibirskaya 15’ are characterized by the largest indicators. The average values were significantly surpassed by the F2population in the traits ‘number of productive anthers per 100 anthers’ and ‘number of all regenerants per 100 anthers’ at 1 mg/l of 2.4-D. The variety ‘Novosibirskaya 15’ surpassed the average values in traits ‘number of sprouts per 100 anthers’ and ‘number of all regenerants per 100 sprouts’ at 2 mg /l of 2.4-D. The trial has shown that the best responsiveness of the anther culture for the studied genotypes was when the growth regulator 2.4-D was added to the induction medium at a concentration of 1 mg/l. The variety ‘Novosibirskaya 15’ has been characterized by good responsiveness in anther culturein vitroand could be used as a donor of valuable alleles in wheat breeding programs using DH technologies.
The purpose of the current work was to identify the efficiency of new biological complex products prepared on the basis of Novokhizol (NVKhZ) with chitosan and Siberian pine bark extract (SPBE) in protecting spring common wheat from root rot and obligate pathogens (powdery mildew, brown rust) in the forest-steppe of the Ob region, and also to establish their effect on yield elements. The trials were carried out with the spring wheat variety ‘Novosibirskaya 29’ in the field of SibNIISR – branch of the ICG SB of RAS (Novosibirsk) in 2023–2024. The method of application of the products was pre-sowing seed treatment and treatment of vegetative plants. There has been established an efficiency of NVKhZ + SPBE against common root rot. The development of the disease on the roots on average over two years decreased from 21.5 to 3.95 %, the biological efficiency of the product was 81.7 %. There has been found that the use of biological products on vegetative plants reduced the damage of plants by obligate pathogens more than pre-sowing seed treatment. Seed treatment with products contributed to an increase in plant height by 8.7 % with NVKhZ + Chitosan and by 6.8 % with NVKhZ + SPBE, root length by 36.3 % with NVHZ + Chitosan, by 22 % with NVKhZ + SPBE and plant biomass by 17.6 %. There has been found a positive effect of Novochizol compositions on the formation of productive stems, a length of the main spike, a number of kernels per main spike, and kernels per plant. There has been established and statistically proved a positive effect of the tested products on crop yields. On average, over the years of study, plant productivity in variants with biological products has exceeded control values by 1.2 times.
Loose smut (Ustilago avenae (Pers.) Jens.) and covered smut (Ustilago kolleri Wille) are considered to be the most harmful and widespread in the forest-steppes of the Pre-Ob region. The poor grain yields in some years could reach up to 25%, and up to 50% in the years of epiphytoties. The purpose of the current study was to identify the resistance of oat varieties to dusty and covered smut in the forest-steppes of the Pre-Ob region. The study was carried out at the phytopathological plot of the laboratory for plant gene pool of the SRIPCB, the branch of Institute of Cytology and Genetics, Siberian Branch of RAS in 2018–2021. The objects of research were Russian varieties from the world collection of VIR named after V.I. Vavilov. There have been studied 64 oat genotypes for resistance to local populations of loose and covered smut. There has been established a significant correlation between plants’ damage caused by loose and covered smut and soil temperature during the period ‘third decade of May – the first decade of June’ (r = 0.76 and r = 0.73). There was no significant correlation between plants’ damage and the average daily air temperature (r = 0.32 and r = 0.48). There has been determined a negative relationship (r = –0.77 and r = –0.71) between the manifestation of the disease and the amount of precipitation during the period ‘sowing-sprouts’. There has been established that most varieties are susceptible to pathogens. According to smut fungi resistance under conditions of an artificial infectious background, there have been identified such oat varieties as ‘Sibirsky Gerkules’, ‘Fakel’, ‘Rysak’ and ‘Uralets’. These varieties are characterized by large productivity, 1000-grain weight, resistance to lodging.