Wild Crop Research Articles

Next-generation sequencing of the mitochondrial genome of Bombus longipennis Friese, 1918 (Hymenoptera: Apidae)

Bombus longipennis is the species of Bumblebees (Hymenoptera: Apidae), which are important pollinators for wild plants and greenhouses crops. The complete mitochondrial genome (mitogenome) of B. longipennis was determined by next-generation sequencing. The mitogenome was 18,458 bp in size with 87.2% A + T content, containing 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes, and an AT-rich control region (D-loop). Gene arrangement was found to be identical to those of other mitogenomes of bumblebees (e.g. Bombus terrestris and Bombus ignitus). All 13 PCGs initiated with typical ATN codons. Among them, 11 PCGs terminated with TAA or TAG; only cox2 and nad4 have incomplete stop codon T. All 22 tRNAs can be folded into typical cloverleaf structure. Phylogenetic analysis based on the concatenated nucleotide sequences of all 13 PCGs indicated that B. longipennis was more closely related to other species of subgenus Bombus, which clustered into a monophyletic group.

Legacy genetics of Arachis cardenasii in the peanut crop shows the profound benefits of international seed exchange

The narrow genetics of most crops is a fundamental vulnerability to food security. This makes wild crop relatives a strategic resource of genetic diversity that can be used for crop improvement and adaptation to new agricultural challenges. Here, we uncover the contribution of one wild species accession, Arachis cardenasii GKP 10017, to the peanut crop (Arachis hypogaea) that was initiated by complex hybridizations in the 1960s and propagated by international seed exchange. However, until this study, the global scale of the dispersal of genetic contributions from this wild accession had been obscured by the multiple germplasm transfers, breeding cycles, and unrecorded genetic mixing between lineages that had occurred over the years. By genetic analysis and pedigree research, we identified A. cardenasii-enhanced, disease-resistant cultivars in Africa, Asia, Oceania, and the Americas. These cultivars provide widespread improved food security and environmental and economic benefits. This study emphasizes the importance of wild species and collaborative networks of international expertise for crop improvement. However, it also highlights the consequences of the implementation of a patchwork of restrictive national laws and sea changes in attitudes regarding germplasm that followed in the wake of the Convention on Biological Diversity. Today, the botanical collections and multiple seed exchanges which enable benefits such as those revealed by this study are drastically reduced. The research reported here underscores the vital importance of ready access to germplasm in ensuring long-term world food security.

Interspecific Sample Prioritization Can Improve QTL Detection With Tree-Based Predictive Models.

Due to increasing demand for new advanced crops, considerable efforts have been made to explore the improvement of stress and disease resistance cultivar traits through the study of wild crops. When both wild and interspecific hybrid materials are available, a common approach has been to study two types of materials separately and simply compare the quantitative trait locus (QTL) regions. However, combining the two types of materials can potentially create a more efficient method of finding predictive QTLs. In this simulation study, we focused on scenarios involving causal marker expression suppressed by trans-regulatory mechanisms, where the otherwise easily lost associated signals benefit the most from combining the two types of data. A probabilistic sampling approach was used to prioritize consistent genotypic phenotypic patterns across both types of data sets. We chose random forest and gradient boosting to apply the prioritization scheme and found that both facilitated the investigation of predictive causal markers in most of the biological scenarios simulated.

A case for conserving plant pathogens

AbstractA case is made for the counter‐intuitive proposal that plant pathologists and plant pathological societies should consider the development of policies for the conservation of plant pathogens. First the report of the Royal Botanic Gardens, Kew, entitled The State of the World's Plants and Fungi 2020, is reviewed briefly. Next, the reasons why plant pathologists should take this report seriously are outlined and the risks to plant pathogen diversity assessed. In this section and all that follow, the paper focuses on fungal (sensu lato) pathogens, although it is suggested that the general principles developed apply to most plant pathogens, whatever their taxonomic status. There then follows an assessment of native plant pathogens in the functioning, stability, and productivity of unmanaged and partially managed plant populations and communities. It is concluded that there is now compelling and growing evidence that very many do play a significant role. Also assessed, more briefly, is the actual or potential value of plant pathogens to human activities, such as selecting for novel disease‐resistance factors in evolving populations of wild crop relatives, developing novel, sustainable plant disease and weed control strategies, use in industrial processes, and use as model systems for research. New and evolving genomics technologies are likely to facilitate significantly the study or selection of the benefits of plant pathogens to ecosystems or human activities. Potential strategies for the conservation of plant pathogens are outlined briefly, including in situ in unmanaged and partially managed ecosystems and centres of diversity of the progenitors of crop species, and ex situ in culture, spore, DNA, and herbarium collections. In these and many other areas of plant pathology, citizen science research groups have a potentially significant role. It is concluded that there is a strong case for plant pathologists and plant pathological societies to develop and act upon strategies for the conservation and sustainable use of plant pathogens.

Adult resistance genes to barley powdery mildew confer basal penetration resistance associated with broad-spectrum resistance.

Powdery mildew isa major disease of barley (Hordeum vulgare L.) for which breeders have traditionally relied on dominant, pathogen race-specific resistance genes for genetic control. Directional selection pressures in extensive monocultures invariably result in such genes being overcome as the pathogen mutates to evade recognition. This has led to a widespread reliance on fungicides and a single broad-spectrum recessive resistance provided by the mlo gene. The range of resistance genes and alleles found in wild crop relatives and landraces has been reduced in agricultural cultivars through an erosion of genetic diversity during domestication and selective breeding. Three novel major-effect adult plant resistance (APR) genes from landraces, designated Resistance to Blumeria graminis f. sp. hordei (Rbgh1 to Rbgh3), were identified in the terminal regions of barley chromosomes 5HL, 7HS, and 1HS, respectively. The phenotype of the new APR genes showed neither pronounced penetration resistance, nor the spontaneous necrosis and mesophyll cell death typical of mlo resistance, nor a whole epidermal cell hypersensitive response, typical of race-specific resistance. Instead, resistance was localized to the site of attempted penetration in an epidermal cell and was associated with cell wall appositions and cytosolic vesicle-like bodies, and lacked strong induction of reactive oxygen species. The APR genes exhibited differences in vesicle-like body sizes, their distribution, and the extent of localized 3,3-diaminobenzidine staining in individual doubled haploid lines. The results revealed a set of unique basal penetration resistance genes that offer opportunities for combining different resistance mechanisms in breeding programs for robust mildew resistance.

Edible plants of the Batak Karo of Merdeka District, North Sumatra, Indonesia

Background: Batak Karo is one of Batak tribes reputed for their local knowledge about the use of plants for purposes such as food. The objectives of this ethnobotanical study were to document local knowledge related to the uses of wild edible plants and to provide ethnobotanical data on edible plants of the Batak Karo ethnic in order to contribute to the Indonesian traditional food knowledge. This paper presents part of the ethnobotanical research carried out in Merdeka District, North Sumatra, Indonesia.Methods: Ethnobotanical information was obtained by interviewing 58 Karonese informants in Merdeka (28) and Jaranguda (30). Fifty-five percent of the interviewed people were men. Informants were determined through purposive sampling with the criteria of being married, using plants in the surrounding environment as food, farmers and having access to the forest. We conducted interviews (semi-structured and not closed questionnaire) during the fieldwork. Results: A total of 53 food plants belonging to 27 families were documented. Thirty percent of the collected species are wild and used for food. Several of these edible plants are also referred as medicinal plants for local people so they could be classified as food medicines. Begonia laruei M. Hughes, Medinilla speciosa Blume, Debregeasia longifoli (Burm. f.) Wedd, Zanthoxylum acanthopodium DC and Eugenia polyantha Barb. Rord. need to be evaluated as potential crops. This study highlights the rich traditional knowledge on edible plants retained by Batak Karo people.Conclusion: The consumption of wild edible plants is still alive in Batak Karo people. The importance of some of these plant species as wild crops must be outlined since they are a source of genetic resources to establish diversity food.

Evaluation of panicle removal methods and crop topping applications as supplemental tools for wild oat (Avena fatua) management

AbstractIncreased frequency and occurrence of herbicide-resistant biotypes heightens the need for alternative wild oat management strategies. This study aimed to exploit the height differential between wild oat and crops by targeting wild oat between panicle emergence and seed shed timing. Two field studies were conducted either in Lacombe, AB, or Lacombe, AB and Saskatoon, SK, from 2015 to 2017. In the first study, we compared panicle removal methods: hand clipping, use of a hedge trimmer, and a selective herbicide crop topping application to a weedy check and an industry standard in-crop herbicide application in wheat. These treatments were tested early (at panicle emergence), late (at initiation of seed shed), or in combination at one location over 3 yr. In the second study, we investigated optimal timing of panicle removal via a hedge trimmer with weekly removals in comparison to a weedy check in wheat and lentil. This study was conducted at two locations, Lacombe, AB, and Saskatoon, SK, over 3 yr. Among all the tested methods, the early crop topping treatment consistently had the largest impact on wild oat density, dockage, seedbank, and subsequent year crop yield. The early (at panicle emergence) or combination of early and late (at initiation of seed shed) treatments tended to reduce wild oat populations the following season the most compared to the late treatments. Subsequent wild oat populations were not influenced by panicle removal timing, but only by crop and location interactions. Panicle removal timing did significantly affect wild oat dockage in the year of treatment, but no consistent optimal timing could be identified. However, the two studies together highlight additional questions to be investigated, as well as the opportunity to manage wild oat seedbank inputs at the panicle emergence stage of the wild oat lifecycle.

Exploration of wheat wild relative diversity from Lahaul valley: a cold arid desert of Indian Himalayas

Climate change is causing a huge loss in biodiversity throughout the globe and the rate has accelerated in recent years. Plant diversity of temperate regions has continuously suffered due to this. The importance of conservation of wild relatives/species of staple crop such as Elymus, Leymus, Thinopyrum, Lolium either in situ or ex situ is essential to sustain these resources for future use due to their ability to withstand in a stressful environment. Thus plant researchers are always in a quest to explore novel species to enhance the genetic diversity of wild crop relatives to improve the resilience of staple crops to a wide range of stress conditions. Keeping these viewpoints in mind, in 2016–2018, we have explored the Lahaul valley, a cold arid region of District Lahaul and Spiti, Himachal Pradesh. A total of 230 accessions of four different species belonging to genus Elymus viz-E. semicostatus (Nees ex steud.) Meld., E. repens Gould, E. dahuricus Turrcz Ex Griseb. and E. longiaristatus (Boiss.) Tzvelev subsp. Canaliculatus (Nevski) Tzvelev belonging to the family Poaceae, tribe Triticeae were taken into consideration. Wide-range of variability was observed at an inter-and intraspecific level among these species. The variations in morphological characters at different ecological amplitudes were recorded. The presence of variation in abiotic stress tolerance traits such as spike pigmentation, low seed shattering, dense pubescence, waxiness was observed. Forty traits were recorded during field evaluation to ease wheat breeders and researchers to identify germplasm during the collection at an in situ level. The population of these four species had a variation for qualitative and quantitative traits at different ecological regimes at their native habitat suggesting their adaptability to a particular niche. Pre-breeding on these germplasm resources could be initiated for introgression novel alleles in wheat to mitigate environmental constraints posed by changing climate.

Comparative Analysis of Essential Bioactive Components of Oils Originating from Three Chinese Loess Plateau Wild Crops

AbstractThe ability of soil and water conservation crops to resist stress is closely related to their abundance of lipid‐soluble chemical components. This study systematically evaluated the composition and content of fatty acids, sterols, squalene, and tocopherol in oils extracted from three varieties of crops growing on the Chinese Loess Plateau with extreme environments. The dominant fatty acids in the wild seabuckthorn pulp oil were oleic acid (29.73%), palmitic acid (26.83%), and palmitoleic acid (25.71%), and those in wild seabuckthorn seed oil were linoleic acid (42.29%), α‐linolenic acid (20.65%), and oleic acid (18.94%). The most abundant fatty acids in wild elaeagnusmollis seed oil were oleic acid (43.29%), linoleic acid (35.93%), and α‐linolenic acid (7.00%). Wild yellowhorn seed oil was rich in linoleic acid (34.14%), oleic acid (25.99%), and erucic acid (8.76%). Seabuckthorn seed oil had the highest levels of total sterols (619.33 mg/100 g), followed by seabuckthorn pulp oil (606.10 mg/100 g), yellowhorn seed oil (249.46 mg/100 g), and elaeagnusmollis seed oil (224.01 mg/100 g). However, the squalene content was highest in elaeagnusmollis seed oil (68.06 mg/100 g) and similarly low in yellowhorn seed oil (9.81 mg/100 g), seabuckthorn pulp oil (4.62 mg/100 g) and seabuckthorn seed oil (4.71 mg/100 g). In addition, seabuckthorn pulp oil had the highest tocopherol content (179.92 mg/100 g), followed by seabuckthorn seed oil (130.57 mg/100 g), elaeagnusmollis seed oil (85.87 mg/100 g), and yellowhorn seed oil (45.44 mg/100 g). This study provides favorable data supporting biomass resource utilization and organic synthesis of bioactive raw chemical composition.

A review on benefits, potential and conservation of Baccaurea lanceolata

Malaysia has introduced the Plant Genetic Resources for food and agriculture (PGR) policy to further research and profile its wild crops to conserve and protect its rich biological diversity. There is an urge for relevant research to be conducted since it may also serve as an identifying accession of desirable traits for crop improvement. One such underutilised plant, Baccaurea lanceolata or locally known as “liposu” by the Dusun people has long played a traditional and cultural role for the local Bornean people. Unfortunately, although in recent years it has gained traction as a traditional food delicacy among the locals, it has remained underutilised and not commercially cultivated due to limited research and exposure. Despite that, limited studies on plants of Baccaurea species have been shown to contain various beneficial properties. The underutilised fruit of Baccaurea lanceolata has a high probability of containing a health beneficial, noteworthy amount of unique, uncovered phytochemicals. Research on this underutilised plant may also provide a path to road of commercialisation as well as preserving this tree from the danger of forest clearing. This review paper has therefore compiled information from available secondary literature on Baccaurea lanceolata in terms of its traditional knowledge, cultural usage as well as studies on its scientifically proven health benefits.

Potential of Underutilized Wild Crops in Koraput, Odisha, India for Improving Nutritional Security and Promoting Climate Resilience

Potential of Underutilized Wild Crops in Koraput, Odisha, India for Improving Nutritional Security and Promoting Climate Resilience

Parasitic nematodes of wild and cultivated subtropical fruit plants in Central Asia

The purpose of the research is studying the species composition and control measures against parasitic nematodes of wild and cultivated subtropical fruit plants of Central Asia.Materials and methods. We studied subtropical fruit crops in 198 farms and 1985 household plots located in various soil and climatic zones of over 20,675 hectares in Central Asia. The materials were collected in the autumn (September-October), spring (April-May) and summer (June-August) months in 1970–1990 by the route method. Study subjects were plant parasitic nematodes of 8 species of wild and cultivated subtropical fruit plants in the Central Asian republics. A modified Baermann funnel method was used to isolate plant nematodes from plants and soil near roots. In total, we collected and analyzed more than 5,400 plant and soil samples. To identify the species of plant parasitic nematodes, we used the Atlas of plant parasitic nematodes compiled at the Institute of Parasitology of the Russian Academy of Sciences, as well as morphometric indicators obtained according to the generally accepted De Mann formulae.Results and discussion. More than 129,000 specimens of plant parasites of 98 species were found in the studied wild and cultivated subtropical fruit crops and soil near their roots. In many farms of the Central Asian republics, we found southern root-knot nematodes, peanut root-knot nematodes, javanese root-knot nematodes, and cotton root-knot nematodes in mixed populations. In Uzbekistan, the prevalence in these crops was from 8 to 61.3%, in Tajikistan – from 78 to 98%, in Turkmenistan – from 6 to 98%, and in Kyrgyzstan – 33%. In addition to root-knot nematodes, representatives of ecto- and endoparasites of the genera Tylenchorhynchus, Merlinius, Quinisulcius, Rotylenchus, Helicotylenchus, Pratylenchus, Paratylenchus, Macroposthonia, Labocriconema and Xiphinema were parasitizing in the above subtropical cultures. Under production conditions, we tested Furadan at a dose of 40 kg/ha, Heterophos at a dose of 60 and 120 kg/ha, and Aldicarb at a dose of 40 kg/ha to control root-knot and other parasitic nematodes. Their efficacy ranged from 89 to 100%. We also used the soil solarization method developed by us, the efficacy of which was 95–98%.

Identification of the Triticoid-type grains (Poaceae) from archaeobotanical assemblages in southwest Asia as Heteranthelium piliferum (Banks & Sol.) Hochst.

The so-called Triticoid-type grains are known from several prehistoric sites in southwest Asia and their identification has long been unclear. They resemble the grains of wheats and researchers suggested they may represent an extinct Triticeae species, possibly closely related to wild crop progenitors. In this study we identify the Triticoid-type grains as Heteranthelium piliferum (Banks & Sol.) Hochst. and describe the key identification criteria. The identification is based on morphological analyses of modern and archaeological material from several grass species and was first achieved with well-preserved specimens from Early Neolithic Chogha Golan, Iran. We further examined the Triticoid-type grains from recently excavated samples from Early Neolithic Ganj Dareh, Iran, and archived samples from Late Chalcolithic and Late Bronze Age Tell Brak in northeast Syria, confirming their identification as H. piliferum. Based on the study of herbarium specimens at Royal Botanic Gardens Kew, London, we provide a detailed distribution map and review the species’ biology and ecological adaptations. Collected and cultivated herbarium specimens were analysed in order to understand the high phenotypic plasticity of the growth habit, its correlation with environmental variables and its relation to grain size. In order to understand the high morphological variability of the charred Triticoid-type grains from archaeological deposits, we assessed the effects of experimental carbonisation at different temperatures on grains of H. piliferum, Triticum dicoccum, T. thaoudar and Secale vavilovii. In light of the present study, we discuss the relevance of H. piliferum for reconstructing prehistoric subsistence strategies.

A Morphofunctional Hypothesis for Selection on EDAR V370A and Associated Elements of Sinodonty

The phenomenon of sinodonty refers to a suite of dental characters shared between East Asian and Native American populations, and most prominently to the presence of shoveled incisors. Although this syndrome is a conspicuous aspect of dental differentiation among extant human populations, elements of which have been recent subject of detailed genetic analysis, adaptive consequences of shoveled incisors and related features remains unclear. Here, I hypothesize that many of the associated differences in dentition (along with reduction in mandibular length and increases in salivary gland branching) arose in parallel with the opportunistic consumption of wild rice and millet in central and northern China, respectively, and with their subsequent domestication in the Upper Paleolithic. More efficient mastication and digestion of plant grains (and of other starchy foods obtained via broad-spectrum foraging) would potentially have been enabled by these traits, yielding greater rates of nutritional intake as wild crops were progressively domesticated. This functional hypothesis, although not mutually exclusive relative to other proposed selective factors, matches the estimated timeline in China for both origin and time to fixation of the associated allele (EDAR V370A), and is consistent with chronic energetic gain and fitness benefits independent of any assumptions for concurrent climatic conditions.

Development of a PCR-based, genetic marker resource for the tomato-like nightshade relative, Solanum lycopersicoidesusing whole genome sequence analysis.

Solanum lycopersicoides is a wild nightshade relative of tomato with known resistance to a wide range of pests and pathogens, as well as tolerance to cold, drought and salt stress. To effectively utilize S. lycopersicoides as a genetic resource in breeding for tomato improvement, the underlying basis of observable traits in the species needs to be understood. Molecular markers are important tools that can unlock the genetic underpinnings of phenotypic variation in wild crop relatives. Unfortunately, DNA markers that are specific to S. lycopersicoides are limited in number, distribution and polymorphism rate. In this study, we developed a suite of S. lycopersicoides-specific SSR and indel markers by sequencing, building and analyzing a draft assembly of the wild nightshade genome. Mapping of a total of 1.45 Gb of S. lycopersicoides contigs against the tomato reference genome assembled a moderate number of contiguous reads into longer scaffolds. Interrogation of the obtained draft yielded SSR information for more than 55,000 loci in S. lycopersicoides for which more than 35,000 primers pairs were designed. Additionally, indel markers were developed based on sequence alignments between S. lycopersicoides and tomato. Synthesis and experimental validation of 345 primer sets resulted in the amplification of single and multilocus targets in S. lycopersicoides and polymorphic loci between S. lycopersicoides and tomato. Cross-species amplification of the 345 markers in tomato, eggplant, silverleaf nightshade and pepper resulted in varying degrees of transferability that ranged from 55 to 83%. The markers reported in this study significantly expands the genetic marker resource for S. lycopersicoides, as well as for related Solanum spp. for applications in genetics and breeding studies.

Genomic diversity and genome-wide association analysis related to yield and fatty acid composition of wild American oil palm

Existing Elaeis guineensis cultivars lack sufficient genetic diversity due to extensive breeding. Harnessing variation in wild crop relatives is necessary to expand the breadth of agronomically valuable traits. Using RAD sequencing, we examine the natural diversity of wild American oil palm populations (Elaeis oleifera), a sister species of the cultivated Elaeis guineensis oil palm. We genotyped 192 wild E. oleifera palms collected from seven Latin American countries along with four cultivated E. guineensis palms. Honduras, Costa Rica, Panama and Colombia palms are panmictic and genetically similar. Genomic patterns of diversity suggest that these populations likely originated from the Amazon Basin. Despite evidence of a genetic bottleneck and high inbreeding observed in these populations, there is considerable genetic and phenotypic variation for agronomically valuable traits. Genome-wide association revealed several candidate genes associated with fatty acid composition along with vegetative and yield-related traits. These observations provide valuable insight into the geographic distribution of diversity, phenotypic variation and its genetic architecture that will guide choices of wild genotypes for crop improvement.

Expression of internal reproductive barriers in a germplasm bank accession of the wild potato Solanum chacoense Bitter in three ex situ regeneration cycles

Wild potatoes (Solanum sp.) are important reservoirs of desirable genes for potato breeding. Most of them are diploid and obligate outcrossers, with both sexual and asexual reproduction. Samples of natural populations are ex situ conserved as accessions in germplasm banks for basic and applied ends, and are regenerated when seed number, seed viability or both decrease. The possible action of within accession internal reproductive barriers is not considered in the current seed regeneration protocols, in which 20 to 25 plants are cultivated for the crossing work. Notwithstanding, the effective number of progenitors (Ne) in every seed regeneration cycle might be reduced in relation to the real number (N) of plants if internal reproductive barriers were acting; this process can eventually lead to gene erosion. To ascertain if Ne = N in seed regeneration of one randomly provided accession of S. chacoense Bitter, pollen viability and size, plus pollen-pistil relationships and number and type (according to endosperm development) of seeds/fruit were studied, respectively, at the individual plant and genotypic combination levels. Two types of barriers, pre-zygotic (pollen-pistil self- and cross-incompatibility) and post-zygotic (male sterility and inviability and weakness of F1 hybrids) were detected in three growing seasons, indicating that not all genotypes in this accession made an equal allele contribution to the next generation. These results should be an alert for germplasm bank curators of wild potatoes and other crop wild relatives. Since the objective of germplasm banks is the ex situ maintenance of the natural genetic diversity, strategies need to be devised based on genetic premises.

Contribution to the knowledge of the bumblebee fauna of Afghanistan (Hymenoptera, Apidae, Bombus Latreille).

Bumblebees (Hymenoptera: Apidae: genus Bombus Latreille, 1802) constitute an important group of pollinators for many wild plants and crops in north temperate regions and South America. Although knowledge of these insects has been increasing over the last decades, some geographic areas remain poorly studied and additions to the knowledge of their faunas are infrequent. Afghanistan is one example of a country that is currently underrepresented in the scientific literature despite its high species diversity. For this study, more than 420 new occurrence records were gathered for 17 bumblebee species belonging to all eight subgenera recorded in the country, including the first record of a species closely related to the Blongipennis group. Additionally, the first standardized database for Afghan bees is launched, which we hope will be enriched in the future to allow further assessments of population trends for the bumblebees of Afghanistan. Finally, the previously published species records for the country are discussed considering the most recent taxonomic revisions of the genus and key perspectives are highlighted for further work in this understudied country and neighboring regions.

Mathematical and information support of the program complex for planning of the harvesting of wild-growing products

The paper presents the results of the development of information and software for a program complex of modeling the harvesting of wild-growing food resources. Linear programming models with interval parameters are proposed to optimize the harvesting of wild-growing food resources. In addition to models with interval parameters, a model of stochastic programming is developed under the condition of stationary state of the yield series of wild-growing crops. Models may contain dependent and independent coefficients for unknowns. The database includes information on the yield of wild crops, labor resources, product prices, questionnaire data filled in by procurement staff, results of field studies on a preliminary assessment of possible harvest, maps showing the territories of commercial resources for each species. The developed software package can be used to simulate the harvesting of wild food resources in any regions with commercial reserves of wild plants. The development results were tested for some municipal districts of the Irkutsk region and model clusters.

Characteristics of powdery mildew and its importance for wheat grown in Poland

Powdery mildew of grasses and cereals (Blumeria graminis) is a fungal plant disease which is caused by species of fungi from the Erysiphaceae order. B. graminis is a biotrophic parasite, biologically diverse parasite with a high degree of specialization in certain host species and with numerous physiological breeds adapted to different varieties of a particular host species. In Poland, powdery mildew of cereals and grasses is recorded every year, and its greatest intensity is in south-eastern and south-western regions. The degree of infestation by B. graminis varies every year. This means that the disease occurs every year, in greater or lesser severity. Therefore, it requires monitoring (harmfulness thresholds) and chemical control practically in every vegetation season. Nowadays, an important role is played by immunological breeding. In breeding programs, resistance genes from wild crop forms, primitive and indigenous varieties are an effective tool. The introduction of effective resistance genes into cultivated varieties is a common procedure used in breeding program.<br />The aim of this study was to describe the fungal disease of plants from the group of powdery mildews caused by <br /> B. graminis as an overview.