scholarly journals Loci that determine long-term resistance to blast of Russian rice varieties

2020 ◽  
Vol 21 ◽  
pp. 00014
Author(s):  
Julia Goncharova ◽  
Olesya Bragin ◽  
Sergey Goncharov ◽  
Evgeny Kharitonov
Keyword(s):  
Pyricularia Oryzae ◽  
Main Role ◽  
Rice Varieties ◽  
Polymorphic Loci ◽  
Rice Plants ◽  
Primary Screening ◽  
Resistant Varieties ◽  
Modern Breeding ◽  
Resistance Of Varieties

In all rice-growing countries, including Russia, among the economically important, dangerous and harmful diseases of rice, the main role is played blast (pathogen Pyricularia oryzae Cavara). The problem of resistance of rice plants to disease is one of the main problems in modern breeding in most countries. The most effective way to protect rice from blast is using resistant varieties created with marker assistant selection (MAS). The article presents data on chromosomal regions that provide long-term resistance of varieties to pathogen in Russia. The groups of stable and unstable samples significantly differed in the presence of polymorphic loci on the fifth, sixth, eighth, ninth and second chromosomes, which reduces the complexity of evaluating selection material due to the primary screening of gene plasms by variability of resistance loci in the identified chromosomal regions.

scholarly journals KETAHANAN DUA PULUH SATU VARIETAS PADI TERHADAP PENYAKIT HAWAR DAUN BAKTERI

2009 ◽  
Vol 9 (2) ◽  
pp. 168-173
Author(s):  
Heru Adi Djatmiko ◽  
Fatichin Fatichin
Keyword(s):  
Incubation Period ◽  
Seed Weight ◽  
Block Design ◽  
Leaf Blight ◽  
Bacterial Leaf Blight ◽  
Resistant Variety ◽  
Rice Varieties ◽  
Environment Friendly ◽  
Rice Plants ◽  
Resistant Varieties

Resistance of twentyone rice varieties to Bacterial Leaf Blight.  Bacterial leaf blight is one of the most important diseases of rice plants.  Resistant Variety is one of safe, effective, and environment friendly alternative controls to suppress the bacterial leaf blight on rice.  The objectives of this research were to find the most resistant varieties against bacterial leaf blight, and to study the yield of inoculated rice varieties. The research was carried out experimentally. This experiment was arranged in Randomized completely block design with 22 treatments and three replicates. Varieties of IR64 as control for susceptible varieties. Observed Variables were incubation period, disease intensity, seed weight per panicle, and seed weight per hills.  The result of this research showed that variety IR 70 was the most resistant variety to bacterial leaf blight. Variety having highest yield was Rojolele with seed weight per hill was 31.17 g.

scholarly journals Immunological variability of rice varieties depending on growing conditions

2021 ◽  
Vol 285 ◽  
pp. 02036
Author(s):  
Olesya Bragina ◽  
Andrey Ogly ◽  
Pshimaf Khachmamuk
Keyword(s):  
Blast Resistance ◽  
Negative Relationship ◽  
Blast Disease ◽  
Rice Varieties ◽  
Genetic Potential ◽  
Clear Differentiation ◽  
New Races ◽  
Growing Conditions ◽  
Modern Breeding ◽  
Resistance Of Varieties

Blast (causative agent Pyriculariaoryzae Cavara) plays an important role among economically important, dangerous and harmful rice diseases of rice in all rice-growing countries, including Russia. The problem of resistance of rice plants to disease is one of the main problems in modern breeding in most countries. Intensification of rice cultivation creates a favorable microclimate in the sowing agrocenosis for the development of blast disease and leads to an increase in its harmfulness. The varieties quickly lose their resistance to new races of the pathogen, due to high spontaneous variability of the M. grisea fungus, its field populations are usually represented by a mixture of races with different virulence and aggressiveness, outstripping the evolution of the host plant. The nature of the blast manifestation depends on the agroclimatic conditions and genotype. The article presents the results of research at experimental and production plots of Federal Scientific Rice Centre (FSC of Rice) and Elite Seed-Production Experimental Statation Krasnaya (ESPES Krasnaya). It has been shown that a clear differentiation of rice varieties in terms of blast resistance and yielding properties is possible only when certain (provocative) conditions are created that contribute to the manifestation of their genetic potential, while the blast resistance of varieties cannot be provided only by the introduction of one gene of racespecific resistance. A close negative relationship was obtained between the yield and the intensity of blast disease on two backgrounds of mineral nutrition: N-1 - r = -0.93; N-2 - r = -0.95. The determination coefficients showed that in 86.8 - 90.1% of cases, the yield is due to the intensity ofblast development on the crops of the studied rice varieties.

scholarly journals Studying of Cultural Properties of Pyricularia oryzae Cav. Strains in the South of Russia

2021 ◽  
Vol 12 (1) ◽  
pp. 21-28
Author(s):  
Dmitry Nartymov ◽  
Evgeny Kharitonov ◽  
Elena Dubina ◽  
Sergey Garkusha ◽  
Margarita Ruban ◽  
...  
Keyword(s):  
Pyricularia Oryzae ◽  
Blast Disease ◽  
The South ◽  
Directional Growth ◽  
Rice Plants ◽  
Affected Plant ◽  
Cultural Traits ◽  
Plant Form ◽  
Using Data

This article presents the results of the development of a methodology for describing the main morphological and cultural traits of the Pyricularia oryzae Cav. strains widespread in the south of Russia. At the same time, the types of traits are identified and listed, which make it possible to unambiguously determine the uniqueness and variety of the pathogen. The relationships and patterns established using cluster and statistical analysis make it possible to identify the conditions for the development of a pathogen that determine its predominant forms. Thus, research shows that leaf forms of P. oryzae strains isolated from rice plants with leaf form of blast disease have an equally directional growth pattern of a colony with a felt structure, and strains isolated from neck-affected plant form often produce a zone of a colony with a clumpy structure. The classification of cultural traits will make it possible to obtain scientifically grounded and comparable data that can be used in the analysis of the interaction of P. oryzae strains with rice plants on various varieties and in various agro-technological conditions in order to improve and rationalize agricultural activities. The study opens up the possibility of using data in breeding, making it possible to identify forms of a pathogen that infect certain varieties.

scholarly journals Development of rice pre-breeding resources with blast resistance

2020 ◽  
Vol 224 ◽  
pp. 04020
Author(s):  
Zh M Mukhina ◽  
E G Savenko ◽  
T L Korotenko ◽  
I I Suprun ◽  
O. A. Bragina ◽  
...  
Keyword(s):  
Magnaporthe Grisea ◽  
Blast Resistance ◽  
Local Population ◽  
Rice Varieties ◽  
Germplasm Exchange ◽  
Yield Structure ◽  
Rice Samples ◽  
Breeding Resources

Within the framework of this study, the first Russian-Chinese joint program for development of rice varieties with long-term blast resistance was launched on the basis of rice germplasm exchange and the subsequent comprehensive study of the obtained breeding samples, hybridization of Russian and Chinese varieties with specified traits. The genetic diversity of the Chinese rice samples obtained by exchange was studied by biological and morphological traits of plants, taxonomic belonging to a botanical variety, elements of the yield structure, and resistance to lodging. 31 hybrid combinations (F1) from the crossing of Russian and Chinese varieties were used to obtain the BC1 generation. The technologies of cultivation of isolated rice anthers in vitro have been optimized in relation to Chinese genotypes in order to accelerate the genetic stabilization of breeding material obtained from crossing. Phenotyping of Russian and Chinese breeding samples was carried out on the basis of resistance to the local population of the blast pathogen (Magnaporthe grisea (T.T. Hebert) M.E. Barr)), on natural and artificial infectious backgrounds. DNA identification of genes for blast resistance was carried out for the same breeding samples. Based on the experimental data obtained, promising samples were selected - prototypes of new rice varieties.

scholarly journals Ketahanan padi (Oryza sativa L.) varietas IPB 3S terhadap wereng batang cokelat (Nilaparvata lugens (Stål) (Hemiptera: Delphacidae)

2020 ◽  
Vol 17 (2) ◽  
pp. 97
Author(s):  
Andi Nurdaaniyah ◽  
Dadang Dadang ◽  
I Wayan Winasa
Keyword(s):  
Sex Ratio ◽  
Insect Pests ◽  
Oryza Sativa L ◽  
Feeding Activity ◽  
Brown Planthopper ◽  
Nilaparvata Lugens ◽  
Population Increase ◽  
Rice Varieties ◽  
High Loss ◽  
Rice Plants

<p>Brown planthopper (<em>Nilaparvata lugens</em> (Stål)) is one of the major rice insect pests that is known to cause high loss of rice production. One of the strategies to control this pest is by using resistant rice varieties. The aim of this research was to study the resistance of IPB 3S variety to BPH by measuring BPH fecundity, sex ratio, feeding activity as well as population increase compared to Ciherang variety against brown planthopper (<em>N. lugens</em>). Fecundity test used a pair of BPH adult infested on 21 days after planting (DAP) of rice plants. Eggs laid in rice stalks and the rest of eggs in the ovary were counted. In order to know the change of sex ratio, a pair of BPH adults was infested on 30 DAP rice plants and allowed to lay eggs. The calculation of sex ratio was conducted at adult stage of BPH by segregation between male and female adults. Feeding activity of BPH was evaluated using ninhydrin and analyzed qualitatively using spectrophotometer. Ten fourth instar nymphs of BPH was infested on 30 DAP old of rice seedlings. Honeydew secreted by BPH was collected to filter paper sprayed with ninhydrin. Population increased test was conducted by infesting five pairs of BPH adults on 35 DAP old rice plants. Observations was conducted on nymph and adult stages. Each test was replicated 10 times. In general, IPB 3S is slightly resistant to BPH, compared to Ciherang variety. The feeding activity of BPH is higher in Ciherang compared to IPB3S. However, the fecundity and population increased of BPH in Ciherang is similar to IPB3S.</p>

scholarly journals Possible Relationship between Long-Term Adverse Health Effects of Gonad-Removing Surgical Sterilization and Luteinizing Hormone in Dogs

Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 599
Author(s):  
Michelle A. Kutzler
Keyword(s):  
Luteinizing Hormone ◽  
Cruciate Ligament ◽  
Transitional Cell ◽  
Reproductive Function ◽  
Receptor Activation ◽  
Main Role ◽  
Nitric Oxide Release ◽  
Neoplastic Tissues

Spaying and neutering dogs is commonly used to prevent the birth of unwanted animals and eliminate the risk of reproductive diseases. However, removal of the gonads prevents the feedback of estrogen and testosterone on the pituitary and hypothalamus. As a result, luteinizing hormone (LH) is continuously elevated at supraphysiologic concentrations. Although the main role of LH is for reproductive function (e.g., ovulation), there are LH receptors present in several normal tissues including the thyroid and adrenal glands, gastrointestinal tract, cranial cruciate ligament and round ligament, and lymphocytes. In addition, there are LH receptors present in several neoplastic tissues (e.g., lymphoma, hemangiosarcoma, mastocytoma, transitional cell carcinoma, and osteosarcoma). The role of LH receptors in non-reproductive normal and neoplastic tissues is not known but may stimulate nitric oxide release and induce cell division. The precise etiology of the increased incidence of several non-reproductive long-term health complications following spaying and neutering is not known but may be related to LH receptor activation in these non-reproductive target tissues. How these effects may be mediated is described in this review.

Development and Investigation of High-Strength Neutron-Absorbing Composite Coatings Based on Borides of Metals

2019 ◽  
Vol 945 ◽  
pp. 660-664 ◽  
Author(s):  
A.S. Larionov ◽  
L.V. Chekushina ◽  
E.E. Suslov
Keyword(s):  
Boron Concentration ◽  
Spent Nuclear Fuel ◽  
Composite Coatings ◽  
High Strength ◽  
Nuclear Materials ◽  
Main Role ◽  
Fission Reaction ◽  
Model Calculations ◽  
Program Show

At present, structural materials capable of absorbing thermal neutrons are used for long-term, compacted storage of spent nuclear fuel. This is necessary to prevent the occurrence of a fission reaction in clusters of nuclear materials. A promising direction in this area is the use of neutron-absorbing coatings. In this paper, it is proposed to use coatings of the B-Ti system for this purpose. The model calculations carried out using the MCU-REA program show the sufficient effectiveness of such coatings. The average path length of the neutron in the coating is ~ 90 μm. The dependence of the degree of attenuation of the neutron flux on the thickness of the coating is shown. Calculations show that the main role is played not by the thickness of the coating, but by the boron concentration in the material. For the synthesis of coatings, the method of magnetron sputtering is considered. Аn experimental magnetron boron-containing target for a four-channel magnetron installation VUP-5M was fabricated.

Sensitivity of Pyricularia oryzae Populations to Fungicides Over a 26-Year Time Frame in Brazil

Plant Disease ◽  
2020 ◽  
Author(s):  
Leilane Silveira D' Ávila ◽  
Marta Cristina Corsi Filippi ◽  
Adalberto Corrêa Café-Filho
Keyword(s):  
Time Frame ◽  
Pyricularia Oryzae ◽  
Active Ingredients ◽  
Melanin Biosynthesis ◽  
Gradual Rise ◽  
Dmi Fungicides ◽  
Term Basis ◽  
Collection Period

The long-term dynamics of fungicide resistance of the rice blast fungus Pyricularia oryzae was monitored by examining the reaction of the fungal field isolates, collected over a period of 26 years, to the active ingredients of commercially relevant fungicides. The in vitro sensitivity of all isolates was measured against Quinone outside inhibitors (QoI), Melanin biosynthesis inhibitors (MBI) and Sterol demethylation inhibitor (DMI) fungicides, namely azoxystrobin (QoI), tricyclazole (MBI), tebuconazole (DMI), and trifloxystrobin + tebuconazole (QoI + DMI). Over the 26-year collection period, a gradual rise in the EC50 estimates for mycelial growth sensitivity was observed for all fungicides, but most strikingly for azoxystrobin. A rise in conidial germination and appressorium formation was also noted, most markedly for azoxystrobin. Consistently, the earlier isolates were much more sensitive to the active ingredients than the more contemporary isolates. The sequencing of the amplified cyt b fragment distinguished two haplotypes, H1 and H2. Haplotype H1 (six isolates) contained the G to C transversion at codon 143 (resulting in change G143A), linked to the resistant phenotype QoI-R. Haplotype H2 (40 isolates), gathered the isolates sensitive to QoI. This work documents the gradual rise in the frequency of fungicide resistant isolates in Pyricularia oryzae rice populations on a long-term basis.

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