scholarly journals COMPARATIVE ANATOMY OF LACRIMAL BONE OF BACTRIAN CAMEL

Author(s):  
А.К. Dnekeshev ◽  
◽  
Е.U. Baitlesov ◽  

Spackled yellows of wheat leaves is caused by pathogen Pyrenophora tritici-repentis (Died.) Drechs.). This is a widespread disease and in addition to wheat, the pathogen affects more than 60 species of cereals and wild relatives. The review presents spread of pathogen in the world and in Russia, its biological features and injurousness, which is associated with reduction of yields up to 60% in the years of its epiphytotic development. Special attention is paid to the racial composition of P. tritici-repentis in various geographical zones and the heterogeneity of the distribution of races in the world. The most common races of spacled yellows pathogen are races 1 (Tox A, Tox C), 2 (Tox A), 7 (Tox A, Tox B), 8 (Tox A, Tox B, Tox C). The formation of atypical races that cannot be referred to the existing classification is noted, which indicates high adaptive properties of the phytopathogen. At present, ubiquitousness of fungus, its high adaptive abilities, saturation of crop rotations with grain crops, cultivation of unstable varieties, minimization of soil cultivation and other reasons will contribute to further spread of the harmful disease, which actualizes the need to develop integrated systems for protecting crops from spackled yellows pathogen.

Author(s):  
Y.S. Kim ◽  
◽  
G.V. Volkova ◽  

Spackled yellows of wheat leaves is caused by pathogen Pyrenophora tritici-repentis (Died.) Drechs.). This is a widespread disease and in addition to wheat, the pathogen affects more than 60 species of cereals and wild relatives. The review presents spread of pathogen in the world and in Russia, its biological features and injurousness, which is associated with reduction of yields up to 60% in the years of its epiphytotic development. Special attention is paid to the racial composition of P. tritici-repentis in various geographical zones and the heterogeneity of the distribution of races in the world. The most common races of spacled yellows pathogen are races 1 (Tox A, Tox C), 2 (Tox A), 7 (Tox A, Tox B), 8 (Tox A, Tox B, Tox C). The formation of atypical races that cannot be referred to the existing classification is noted, which indicates high adaptive properties of the phytopathogen. At present, ubiquitousness of fungus, its high adaptive abilities, saturation of crop rotations with grain crops, cultivation of unstable varieties, minimization of soil cultivation and other reasons will contribute to further spread of the harmful disease, which actualizes the need to develop integrated systems for protecting crops from spackled yellows pathogen.


Author(s):  
Yu. K. Shashko ◽  
M. V. Podorskiy

 From the point of view of economic efficiency and environmental impact in the country, the most profitable way to fight the Pyrenophora tritici-repentis agent is creation of highly resistant varieties, which is relevant and important in increasing crop gross yield and ensuring food security in the country. Pyrenophorosis (spackled yellows) is a relatively new disease of winter wheat in the Republic of Belarus. No aimed researches for occurrence monitoring, predominant racial composition, biological peculiarities of pathogen, search for resistance sources in the country were carried out, which collectively determined the relevance of the research topic. The paper presents results of study of spackled yellows agent occurrence of winter wheat leaves in the Republic of Belarus (2016-2018), as well as racial composition. Route examinations revealed disease in all the areas of the country, which indicates a potentially high risk of this disease. Analysis of racial composition showed that race No. 8 of spackled yellows pathogen prevails on the territory of the Republic of Belarus, No. 1 and No. 6 races occur insignificantly. Laboratory experiments were conducted to identify the best artificial nutrient medium, exposure at low temperatures to stimulate the pathogen sporulation in order to obtain high-quality inoculum necessary for artificial infection. Against background of artificial infection, the world and Belarusian collections of winter wheat were analyzed for resistance to pyrenophorosis Pyrenophora tritici-repentis (283 and 47 pieces, respectively). For three years of estimation, 28 variety samples of winter wheat with increased resistance to the disease were allocated from the world collection and 19 variety samples - from the Belarusian collection. It was determined that the greatest number of resistant samples to spackled yellows of winter wheat leaves come from Europe and Belarus in particular. Acknowledgments. Research was conducted as part of the state program of scientific research for 2016–2020 “Quality and efficiency of agro-industrial production”, subprogram “Agriculture and Selection”, task 6.13 “Study of species diversity of winter wheat of various ecological and geographical origin and identification of sources of resistance to the main pathogens”. 


Author(s):  
M. B. Ellis

Abstract A description is provided for Pyrenophora tritici-repentis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Wheat, rye, barley, Agropyrons repens, Cynodon dactylon, Elymus glaucus. DISEASES: Causes yellow leaf spot of cereals and grasses; oval to lanceolate. yellow to grey brown lesions often with a yellow halo. The lesions can be distinguished from those caused by Cochliobolus sativus because of their lighter colour. The disease results in premature death of leaves. It can also cause a seedling blight and root rot. Common and widespread on Agropyron repens[Elymus repens] and wheat, occasionally on barley and rye and recorded on many other grasses. Sometimes causes severe leaf wilt and spotting especially on durum wheat. Leaves of Agropyron repens[Elymus repens] when attacked gradually lose their colour and wither from the tips backwards; they become at first pale yellow, later grey. On wheat fusiform, oval or lanceolate spots, 0.5-2 cm long, 2-4 mm wide are formed. These are at first yellow but later turn brown or greyish brown often with a yellow halo. The leaves die prematurely from the tip backwards. GEOGRAPHICAL DISTRIBUTION: Australia; Asia (Japan, India, Nepal); Africa (Uganda, Kenya, Tanzania, Ethiopia); Europe (Britain, Germany, Czechoslovakia, Sweden, Cyprus); S. America (Bolivia); and N. America (Canada, USA). TRANSMISSION: Air-borne spores (51, 1045p), seed-borne by both external contamination and internal infection (34, 24), secondary grass weed hosts (11, 695), carryover on stubble and other crop debris (43, 1225f; 52, 685).


2018 ◽  
Vol 28 (3) ◽  
pp. 137-146 ◽  
Author(s):  
Adam Kuzdraliński ◽  
Hubert Szczerba ◽  
Anna Kot ◽  
Agnieszka Ostrowska ◽  
Michał Nowak ◽  
...  

We developed new PCR assays that target beta-tubulin (<i>TUB2</i>) and 14 alpha-demethylase (<i>CYP51</i>) genes and used them for the species-specific detection of <i>Blumeria graminis</i> f. sp. <i>tritici</i> (<i>Bgt</i>). Based on fungi DNA sequences available in the NCBI (National Center for Biotechnology Information) GenBank database we developed simplex and duplex PCR assays. The specificities of the primer sets were evaluated using environmental samples of wheat leaves collected during the 2015/2016 growing season across Poland. Primer sets<i></i> LidBg17/18 and LidBg21/22 strongly amplified fragments of the expected length for all 67 tested samples. Primer specificity was confirmed using field samples of <i>Zymoseptoria tri­tici</i>, <i>Puccinia triticina</i> (syn.<i> P. recondita</i> f. sp.<i> tritici</i>), <i>P. striiformis</i> f. sp.<i> tritici</i>, and <i>Pyrenophora tritici-repentis</i>.


1988 ◽  
Vol 1 (21) ◽  
pp. 198
Author(s):  
James R. Walker ◽  
Andrea Bertolotti ◽  
Reinhard E. Flick ◽  
C. Robert Feldmeth

Tidal wetland preservation, restoration and creation have become requisites for coastal development projects in the United States. A basic approach to design of tidal wetlands is presented, stressing cooperation between regulatory agencies, biologists, engineers, and developers. Basic principles of wetland functions are explained and presented as criteria for engineering design. A description of wetlands is given to identify biological features relevant to design. Also, some key features of tides are summarized as they affect wetland design. A numerical model was used to demonstrate how tidal wetlands may be designed to conform with criteria developed by the agencies and biologists. This approach has been used on wetland designs in California, but the approach may be applicable to other areas of the world.


2021 ◽  
Vol 182 (4) ◽  
pp. 102-107
Author(s):  
A. V. Shlyavas ◽  
D. D. Telezhinskiy ◽  
L. V. Bagmet

Researchers of the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) and Sverdlovsk Horticultural Breeding Station developed nomenclatural standards for 18 apple cultivars released at the said station: ‘Aksyona’ (WIR-53949), ‘Blagaya Vest’ (WIR-53950), ‘Danila’ (WIR-53952), ‘Isetskoye Pozdneye’ (WIR-53953), ‘Iset Belaya’ (WIR-53954), ‘Krasa Sverdlovska’ (WIR-53955), ‘Papiroyantarnoye’ (WIR-53956), ‘Pervouralskaya’ (WIR-53957), ‘Rodnikovaya’ (WIR-53958), ‘Rumyanka Sverdlovskaya’ (WIR-53959), ‘Sverdlovchanin’ (WIR-53960), ‘Serebryanoye Kopyttse’ (WIR-53961), ‘Sokovoye 3’ (WIR-53962), ‘Tavatuy’ (WIR-53963), ‘Uralets’ (WIR-53964), ‘Fakel’ (WIR-53965), ‘Fermer’ (WIR-53966), and ‘Ekrannoye’ (WIR-53967). Nomenclatural standards serve to confirm the authenticity of a cultivar and its name. They should be kept perpetually in the scientific herbarium collection. Herbarium specimens of nomenclatural standards are formatted in accordance with the recommendations of the International Code of Nomenclature for Cultivated Plants (ICNCP), registered in the VIR Herbarium Database and included in the Herbarium of Cultivated Plants of the World, Their Wild Relatives, and Weeds (WIR).


2019 ◽  
Author(s):  
Nina V. Mironenko ◽  
Alexandra S. Orina ◽  
Nadezhda M. Kovalenko

This study shows that the necrotrophic effector gene ToxA is differentially expressed in isolates of P. tritici-repentis fungus at different time periods after inoculation of the wheat variety Glenlea which has the gene Tsn1 controlling sensitivity to the necrosis inducing toxin Ptr ToxA. Two P. tritici-repentis isolates with different ability to cause necrosis on the leaves of Glenlea variety (nec + and nec-) and with different expression level of ToxA and gene of factor transcription PtrPf2 in vitro were used for analysis. Isolates of P. tritici-repentis are characterized by the differential expression of ToxA in planta. The expression of the ToxA gene in P. tritici-repentis ToxA+ isolates significantly increased when infected the wheat leaves compared to ToxA expression results obtained in vitro. The levels of ToxA expression in both isolates differed significantly after 24, 48 and 96 hours after inoculation, however, the dynamics of the trait change over time were similar. However, the highest ToxA expression in the virulent (nec+) isolate in contrast with the avirulent (nec-) isolate was observed at a point of 48 hours. Whereas the expression of regulating transcription factor PtrPf2 in planta differed imperceptibly from expression in vitro throughout the observation period. Obviously, the role of the fungal transcription factor in regulating the effector gene expression weakens in planta, and other mechanisms regulating the expression of pathogen genes at the biotrophic stage of the disease develop.


2021 ◽  
Vol 11 (6) ◽  
pp. 37-39
Author(s):  
Nilesh A. Madhav

Grasses (Poaceae) are the monocotyledonous, herbaceous plants with cosmopolitan in distribution. In food chain and ecology, it plays an important role as a base resource. Maize is the well-known plant of tribe Maydeae of the family Poaceae which is used all over the world for food, fodder, beverages and primary source for production of milk and meat. Only few grasses are well-known for their medicinal value. Present study is an overview of Tribe Maydeae with special approach to endemic wild relatives and in context of future aspect in ethnomedicinal and pharmacological studies.


Conservation ◽  
2021 ◽  
pp. 361-400
Author(s):  
Charles Perrings

The final chapter considers the factors likely to influence the value of species and ecosystems to individual users and the wider community in the future, including the factors likely to drive a wedge between the value of ecosystems to individual users or individual communities and to the rest of the world. It reviews environmental trends identified by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, and economic trends identified by organizations such as the World Bank. Using the European Union’s subsidiarity principle as a guide, the chapter discusses the optimal scale at which to manage future conservation challenges, and the implications this has for governance. It concludes by applying the discussion to four issues of particular concern: forest conversion, the loss of landraces and crop wild relatives, marine capture fisheries, and emerging infectious zoonoses.


2018 ◽  
pp. 6-17
Author(s):  
І. Prymak ◽  
А. Panchenko ◽  
M. Voitovyk ◽  
V. Karpenko ◽  
S. Levandovska ◽  
...  

The evolutional way of developing of the theoretical and practical basis of main tillage since the middle of the first part of the 20th century up today is highlighted. Exaggerated ideologization of science, government monopoly of academician V.R. Williams from thirties to fifties years of the 20th century caused big losses in agrarian science, especially in farming and agriculture sciences. The disaster of Williams was caused by absolute priority of soil conditioning and universalization of developed by him grass rotation system of farming. Till fifties in crop farming arable tillage to the depth at least 20–22 cm dominated completely. The first person in the USSR to refuse from a plough was T.S. Maltsev who recommended to hold deep beardless tillage once in 4–5 years, and for the rest of the time to use surface one (up to 8 cm) or surface tillage (10–12 cm) with discs. After T.S. Maltsev works, the issues of differentiation of tilled soil layers under beardless and surface tillage became especially controversial. The final boost for the development of theoretical and practical basis of tillage minimization was soil protecting system suggested by the group of scientists of the former All-Soviet Union Research Institute of grain growing headed by O.І. Baraievyi. It was based on beardless tillage, sowing with stubbly seeding machines, flap and buffer planting, snow capture etc. Early adopters of a full refusal from beard tillage in Ukraine during 80–90ies years were І.Ye. Shcherbak, F.M. Morgun, M.K. Shykula, S.S. Antonets and their students and followers. Nowadays the majority of national scientists consider the differential different depth tillage as the most effective one during crop rotations, which includes alternation of different ways, events and means of soil tillage depending on ecological conditions, crops biological features, structure of crop acreage, fertilization systems and plants protection etc. In scientists opinion, the minimal tillage is available on 3 millions of hectare and no-tillage is available on 5,49 millions of hectare out of 30 millions of tilled soils in Ukraine. In thirties V.R. Williams and M.S. Sokolov criticized surface tillage. Academician M.M. Tulaykov who was openly against doctrines of V.R. Williams recommended surface tillage in dry regions which in his opinion had to protect tilled soil from wind formed processes. He claimed that surface tillage is economically suitable for poor husbandries and that dust storms are the result of a constant daily soil drifting caused by deep tillage. In forties an American farmer E. Folkner widely promoted surface tillage together with soil mulching with plant matters of green crops. The first person to refuse from beard tillage in the first part of the 20th century in the Soviet empire was T.S. Maltsev. He proved decisively the advantages of beardless tillage over beard one in Transurals. T.S. Maltsev suggested the whole range of tools for soil tillage developed by him, the main of which were cultrate pulverizers and a beardless plough. The necessity of tillage with plough was the main stereotype existing in the world tillage theory and practice till the fifties. Scientific inheritance of M.M. Tulaykov became one of the bases for reconsideration of the concept of V.R. Williams existing in Ukraine. He concluded that it was necessary to change beard tillage to surface one to the depth 10-12 cm under which root system of one-year-old plants would be decomposed in tight soil where anoxic conditions must dominate. And to cultivate bottom layers it was necessary to hold deep tillage with beardless ploughs once in 4–5 years. The first person to refuse from a plough in the USSR was T.S. Maltsev. He suggested using surface plowing with disc tillers and deep beardless tillage (40–50 cm) once in 4–5 years instead of tillage in crops rotation of Transural. In 1952 he made a beardless plough for the first time. The most controversial issue among the scientists of Ukraine was differentiation of the tilled layer and its effect on crop productivity under beardless and surface tillage. In sixties and seventies O.I. Baraiev and his colleagues from All Soviet Union Research Institute of grain farming headed by him developed for the first time a soil protective system based exceptionally on different depth beardless tillage in crop rotations, usage of stubbly seeding machines, subsurface cultivators, soil spikers, coulisse fallow, buffer planting etc. In Ukraine during eighties and nineties years a complete refusal from beard tillage in favor of beardless tillage was supported by І.Ye. Shcherbak, F.T. Morgun, M.K. Shykula, S.S. Antonets and other scientists and experts. High weed infestation of fields under such tillage was the main obstacle to its widespread usage. In the 21st century the majority of scientists recommend differential different depth main tillage which suggests different ways, events and means of its implementation in crop rotations depending on biological features of crop, soil and climate conditions, fertilizing systems, plant protection etc, 13 millions hectare of tilled soil is technologically suitable for minimum tillage in Ukraine, and the rest 5,5 million hectare do not even need tillage at all. Key words: tillage, soil, evolution, plough, subsurface cultivator, erosion, minimization, differentiation.


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