Brown Leaf Rust Research Articles

Characteristics of brown leaf rust virulence on winter durum wheat varieties in the Rostov region

The purpose of this work was to characterize the virulence of the P. triticina population on durum wheat in the Rostov region and to assess the leaf rust resistance in the promising winter durum wheat varieties selected by the “ARC “Donskoy”. The joint studies were conducted in the laboratories of FSBSI “Agricultural Research Center “Donskoy” and FSBSI All-Russian Research Institute of Plant Protection. The samples of pathogen populations were collected on durum wheat varieties “Donchanka”, “Lazurit”, “Donskoy Yantar” and “Prikumskaya 142” and propagated on the susceptible soft and durum wheat varieties in the laboratory. There were studied 64 mono pustular isolate. The studied isolates were avirulent to the Thatcher lines with the genes Lr2a, Lr2b, Lr2c, Lr9, Lr15, Lr16, Lr19, Lr20 and Lr24 and were virulent to Lr3a, Lr3bg, Lr3ka, Lr10, Lr11, Lr14a, Lr14b, Lr18, Lr26, Lr30 и Lr44. All samples of populations propagated on durum wheat were characterized by avirulence to the TcLr17 line, and those propagated on soft wheat were mainly characterized by virulence. In general, the conducted analysis revealed significant differences in the composition of pathogen populations on durum and soft wheat. The isolates from durum wheat had a significantly smaller number of virulence alleles, compared with the isolates from soft wheat. In addition, there were observed differences in the latent period of isolates developing on soft and durum wheat (it was less on soft wheat). In 2015-2017 there were studied 17 varieties of winter durum wheat in the laboratory and field conditions. The variety “Arena” and line KS-586/13 were characterized with a high level of resistance in the field (0-5% of infestation) and laboratory conditions (score 0-2). There were identified the weakly susceptible varieties “Yubilyarka”, “Lazurit”, “Kurant”, “Aksinit”. A moderate infestation throughout all years of study was established on the varieties “Yakhont”, “Terra”, “Diona”, “Kristella”, “Agat Donskoy” (10-20%). The variety “Donchanka” (50-60% in 2015-2016; 40-50% in 2017) belongs to the susceptible group. The varieties “Donskoy Yantar”, “Gelios”, “Yantarina” and “Amazonka” were of medium susceptibility (20-40%).

Physiologic specialization and shift in Puccinia triticina pathotypes on wheat in Indian subcontinent during 2013–2016

Brown (leaf) rust of wheat (Puccinia triticina) was widely prevalent in all the wheat growing areas of India and neighbouring countries during 2013–16. To have an effective rust management strategy, monitoring of virulence patterns of P. triticina on wheat were undertaken. Brown rust samples were analyzed from the wheat growing areas in India, Bangladesh, Bhutan and Nepal using standard differential Indian System and named as per the binomial system of nomenclature. A new pathotype 77-12 was also identified during this period. Thirty seven pathotypes of P. triticina were identified in 1427 samples. Five predominant pathotypes 121R63-1(77-5 = THTTM), 121R60-1(77-9 = MHTKL), 21R55 (104-2 = PHTTL), 21R63 (104-3 = PHTTL) and 77-11(125R28 = MGTTL) accounted for 75.1% of the population. All of the prevalent pathotypes are virulent to Lr1, Lr3, Lr10, Lr11,Lr12 Lr13, Lr14a, Lr16, Lr17, Lr23, Lr26. Virulences for Lr9 and Lr19 though recorded from India long back, however, were not observed during present surveys whereas virulence on Lr28 was identified in 0.4% samples only. The proportion of pathotype 121R60-1 (77-9 = MHTKL) has increased during these years and was recorded in 23.7% samples against 12% in the previous report. Brown rust of wheat was not observed on Lr9, Lr24, Lr25, Lr32, Lr39 and Lr45 in the field population of Indian subcontinent during 2013–16. Diversity of pathotypes detected during this period could, to some extent, be related to cultivation of different varieties but was also appeared to be affected by different weather patterns in different agro-ecological areas.

ПЕРСПЕКТИВЫ УЛУЧШЕНИЯ И СОХРАНЕНИЯ КУЛЬТУРЫ TRITICUM SPHAEROCOCCUM PERC.

Attempts to create commercial variety Triticum sphaerococcum Perc. were realized only on the basis of the recombinant mutant KH 4333, created by Krasnodar Scientific and Research University of Agriculture, but the sphericity of obtained varieties is not associated with the sphericity of the Hindustan indices. The disadvantages of T. sphaerococcum samples in the Republic of Tatarstan are (in the study of 2012-2017): low productivity, which varies considerably in the years of the study, in some years the productivity of the best samples did not exceed 0.57 tons per hectare (the Simbirtsit standard did not fall below 2 , 15 tons per hectare); late ripeness; strong defeat of powdery mildew up to 90% in the epiphytotinous year 2017; strong susceptibility to stem rust. The degree of damage to brown leaf rust, in all years, was at the level of the susceptible standard of the Simbirzit variety. We made an attempt to improve the index samples by incorporating T. polonicum L. into the hybridization in order to increase the mass of the grains while maintaining the spherical shape, since hybridization with T. aestivum does not make significant progress. And the inclusion in the hybridization of Triticale 6x, in order to increase resistance to disease. Progress is shown in increasing productivity and resistance to powdery mildew in hybridization with T. aestivum. The constant lines of T. sphaerococcum have been preserved which retained the positive features inherent in this species with a significant increase in yield from 1.34 tons perhectare in the original form to -45738 to 3.77 tons per hectare near the line Ksh-359-11-5, this line is characterized by a high resistant to powdery mildew, but this line has a yield of 23% lower than the best zoned variety Yoldyz.

Распространение болезней пшеницы озимой в Украине

Industrialization of agriculture is accompanied with increase of anthropogenic load on the environment and agriculture product degeneration. That leads to search of alternative, innovation and natural management principles connected with organic farm. The transition to new principles of crop production is a responsible step requiring consideration of all factors affecting the development of crops. One of these factors is the phytosanitary state of crops, including the destruction of their crops by diseases. For timely and effectively counteract the infection of the crops, it is also necessary to constantly monitor the condition of the crops and analyze its results both in a separate section of the field and in regions across the country. The purpose of the work was to assess infection of winter crops based on an analysis of annual reports of the State Service of Ukraine on Food Safety and Consumer Protection from 2012 to 2017. As a result, the following conclusions were obtained: winter wheat leaf blotch (43.69%) and powdery mildew (44.32) are the most widespread; root rot (29.83%) and brown leaf rust (22.65%) have mean value of prevalence and Helminthosporium leaf blight (9.76%) is not widespread in most regions. The mean values of the disease development were distributed as follows: powdery mildew - 3,71%, septoriosis - 3,21%, root rot - 2,92%, brown leaf rust - 2,57%, Helminthosporium leaf blight - 0,85%. Based on arithmetic mean values of the five examined diseases, it was found that the most damage by diseases was in Donetska region - 75.8%, Vinnytska, Sumska regions - 51%, Khmelnytska region - 49.7%, Chernivetska region - 41.6%, Kyivska region - 40.6 %, Volynska region - 36.5% and Ternopilska region - 34.4%. Since organic farming supposes the refusal from synthetic pesticides application, the introduction of organic methods is reasonable in farms located in regions that are the most subjected to disease, namely Luganska, Odeska, Khersonska, Mykolaivska, Dnipropetrovska, Cherkaska, Zhytomyrska, Zakarpatska, Chernigovska and Kharkivska regions Keywords: crop, disease, winter wheat, infection, organic farm

Сравнительное изучение устойчивости Brachypodium distachyon и казахстанских сортов мягкой пшеницы к Puccinia recondita A. I. Zhussupova

One of the important issues of the modern world economics is ensuring the quality of food, relevant for Kazakhstan, where the possibility of cultivating soft and hard wheat varieties and high technological quality grain production are among the strategically important tasks of its national security. Biotic and abiotic environmental stress factors may lead to decrease in cereals productivity, and annual loss in the global yield of crops from diseases, according to FAO, is estimated at more than $25 billion, equivalent to 35% of the potential harvest.  At the same time, creation of pathogen-resistant varieties of cultivated plants by means of traditional breeding is long-term, and the evolution of pathogens is ahead of the possibilities of practical breeding, resulting in creation of pathogen resistant varieties being late with their introduction into production; for a deeper understanding of the basics and in terms of accelerating processes in the leading countries of the world, model organisms are involved into the process.  The aim of this work is to estimate the influence of brown leaf rust on the elements of productivity and protein content in grain of local varieties of soft wheat Kazakhstanskaya 19, Kazakhstanskaya early and new model object Brachypodium distachyon along with their correlation. The results of the comparative study of the impact of biotic stress on the elements of productivity have shown that Puccinia recondita statistically significantly reduces the productivity of all parameters in wheat varieties Kazakhstanskaya 19, Kazakhstanskaya early and model object Brachypodium distachyon. The protein content in the grain of wheat of local breeding varieties Kazakhstanskaya 19, Kazakhstanskaya early and wild cereal Brachypodium distachyon is not changed when infected with brown leaf rust. Key words: Brachypodium distachyon, Kazakhstani soft wheat varieties, brown leaf rust, resistance, study.

Diseases of leaves in triticale and spelt in Ukrainian Polissia

There were studied the peculiarities of fungal diseases of triticale and spelt in the conditions of Ukrainian Polissia. It was found that Septoria leaf blotch and powdery mildew have a dominant role in the pathogenic complex of both cultures as their relative shares are 34.0 and 23.0% respectively in the complex of triticale leaf mycoses, and 52.0 and 36.0% respectively in the complex of spelt leaf mycoses. It was noted that such diseases as tan spot, brown leaf rust and snow mold rarely occurred on winter triticale plants, and such diseases as ascochyta leaf blight, spot blotch and Fusarium disease were episodic in nature. Development of tan spot and spot blotch on spelt plants had non-systematic character. It was established that on spelt wheat level of disease severity is lower and number of pathogens is less

Patterns of physiologic diversity of Puccinia triticina on wheat in Indian subcontinent during 2008-2013

Brown (leaf) rust of wheat, caused by Puccinia triticina was widely distributed in all the wheat growing areas. To identify new pathotypes and determine the virulence pattern of Puccinia triticina, rust samples were analyzed from the wheat growing areas in India, Bangladesh, Bhutan and Nepal. A new pathotype 93R57 (104-4=NHKSP) was identified from Arki area of Solan district in Himachal Pradesh. Among the 37 pathotypes identified in 2124 samples analyzed during 2008-2013, four predominant pathotypes 121R63-1(77-5=THTTS), 21R55 (104-2=PHTTL), 121R60-1(77-9=MHTTS) and 21R63 (104-3=PHTKL) accounted for 68% of the population. These four pathotypes have virulence to Lr1, Lr3, Lr10, Lr11, Lr12, Lr13, Lr14a, Lr16, Lr17, Lr23, Lr26. Virulence on Lr19 was found in 7 samples only whereas the proportion of pathotype 121R60-1 (77-9=MHTTS) has increased recently in Tamil Nadu and was identified in about 40% of the samples from that area. Virulent pathotypes on Lr9, Lr24, Lr25, Lr32, Lr39 and Lr45 were not observed in the field population of brown rust in the Indian subcontinent during the last five cropping seasons.

Immunological reactions of winter soft wheat collection samples for resistance to brown rust

Introduction. One of the central issues in the selection this creating varieties that combine high productivity potential, grain quality with its genetic protection against diseases. The factors that reduce yields and gross harvests of staple food crops of winter wheat, should include numerous diseases, among which a special place is occupied by different types of rust. One of the most economically important and dangerous leaf diseases of winter wheat is brown leaf rust. The aim and tasks of the study. The aim of our research was to determine the resistance to leaf rust collection samples of soft winter wheat on artificial infectious background. The objectives study was to assess the collection and selection of samples of material with a high resistance for use in breeding. Materials and methods . Evaluation of 78 collection samples of winter wheat for resistance to leaf rust was conducted on an artificial infectious background in the field during 2013 - 2014. Results and discussion . Meteorological conditions during years of the study were characterized by fever and unstable air moisture. So, in 2013 during the growing season HTC was 1.3, and in 2014 was 1.6. From the collection of winter wheat, which we studied in 2013-2014 years, 60 samples (76.9%) were high resistant. 12 samples were immune (15.4%), they were originating mainly from the United States and Hungary. Conclusions. Within two years of research to determine the stability of the collection material of winter wheat against leaf rust in the conditions of artificial infection background. Among the 78 samples there were 12 immune, 48 highly resistant, 11 resistant, 5 moderately susceptible, 2 susceptible. Emphasis immune samples Beres, Lurda 81, Lindon, Co 7250-49, Co 7250-50, HBE 384, Mc Nair 2203, Century, TAM-200, Arthur 71, Rochy and Polovchanka, You need to attract crossover and used in breeding work towards the creation of varieties with increased resistance to leaf rust.

Устойчивость сортов Triticum Aestivum разного происхождения к биотическим стрессорам в условиях лесостепи и степи Оренбургского Предуралья

The article summarizes the results of surveys on the development of the spring wheat disease. The composition of the pathogenic complex in the Orenburg region was analyzed. The paper cites an assessment of the stability of varieties of different origin in the forest steppe and steppe zones of Orenburg Urals. The most common and harmful diseases of spring wheat were: brown leaf rust (Puccinia triticina), stem rust (Puccinia graminis), oidium (Erysiphe graminis, Blumeria graminis Speer.), helminthiasis and fusariose root rot (Bipolaris sorokiniana and Fusarium spp.). Among the samples of local breeding Orenburgskaya 13 variety was the strongly susceptible to the disease of wheat. Logachevka and Uchitel variety were mildly susceptible. Varyag variety was characterized by susceptibility to leaf rust, oidium and dust-brand. According to the complex resistance to diseases of the local races of wheat, we can allocate the following varieties: in the forest-steppe zone: Kinelskaya 59, Kinelskaya 60, Saratovskaya 55, Tulaykovskaya 5, steppe Tulaykovskaya, YuV 4 and in the steppe zone - Belyanka, Saratovskaya 70, Tulaykovskaya 10 and steppe Tulaykovskaya. The inclusion of these varieties in the hybridization will provide a more disease-resistant hybrids and new varieties of spring wheat.

Stan fitosanitarny pszenicy ozimej a nawożenie mikroelementami

The Boomer variety of winter wheat was cultivated in a strict plot experiment, in a system of random blocks, and in three repetitions. Seven treatments of fertilization were included in the experiment. The objective of the research was to determine the effect of a foliar application of microelements and Nano-Gro vaccine on infection of pathogens of winter wheat leaves, ears and the stem base. In both vegetation seasons, the symptoms of Septoria tritici infection were the most frequently observed on winter wheat leaves, with dominance of 50% in 2012. In that season the significant differences in Septoria disease severity were observed within fertilized treatments. Similar phenomena was recorded for brown leaf rust (Puccinia triticina) intensity – with the highest infection level at 25%. A minor intensity of powdery mildew (Blumeria graminis) and brown leaf rust symptoms were observed in 2013. Fusarium head blight (FHB) showing minor intensity occurred in both analysed years, with significant differences between fertilizing options. In 2013, a high intensity of symptoms of Septoria disease and Cladosporium spp. and Alternaria sp. disease was observed for ears, and the effect of applied fertilization was ambiguous. On the stem base, in both years of the study, the most frequently observed symptoms were those caused by infection of Fusarium spp. and Tapesia spp., more rarely by Rhizoctonia cerealis, and occasionally by Gaeumannomyces graminis that appeared only in 2012. The applied treatments of mineral and microelement fertilization and the vaccine did not differentiate the intensity of the diseases (exceptions: infection by G. graminis in 2012, and by Tapesia spp. in 2013).

Molecular Phylogenetic Relationships of the Brown Leaf Rust Fungi on Wheat, Rye, and Other Grasses.

The classification of brown leaf rust fungi (Puccinia recondita complex and allied species) on wheat (Triticum aestivum), rye (Secale cereale), and other grasses in the family Poaceae has experienced a long history of controversy and uncertainty due to the reduced morphological characteristics available for taxonomy and difficulty of conducting interfertility experiments. However, because these are pathogens on important crops, it is important to clarify the species delimitations reflecting the natural lineages. In this study, phylogenetic analyses were conducted with DNA sequence data from the ribosomal DNA internal transcribed spacer region and elongation factor 1-α to elucidate this species complex. Three phylogenetic lineages were recovered within the complex of rye leaf rust fungi, P. recondita sensu stricto, which is congruent with existing classifications based on DNA content, sexual compatibility, and morphological studies. The brown leaf rust fungus on wheat (P. triticina) grouped with the related species P. persistens on Elymus repens and E. intermedia as a strongly supported clade. Collections on other Elymus spp. were separated into six clades. Based on the phylogenetic affinities of nine type specimens and aecial host associations, potential taxonomic names were evaluated for selected lineages.

Analysis of wheat (Triticum aestivum L.) brown rust (Puccinia triticina) disease factor and identification of resistance genes in wheat germ plasms in Iran

The brown (leaf) rust disease of wheat, which is caused by Puccinia triticina¸ is one of the most important diseases in Iran. Investigation of the virulence factors and physiologic races is necessary to produce resistance cultivar in order to study 32 different brown rust isolates for pathogenic factors with the 55 differential genotypes of brown rust studied. Also, 20 elite lines/cultivars of wheat reactions with respect to recognise probable presence of the resistant genes were evaluated. On the base of the resulted, none of them showed pathogenicity for the plants containing genes Lr2a, Lr19, Lr25, Lr28, Lr23 and Lr10+. In Islamabad1 isolate and sari2, each with 80% of pathogenic abundance was located in most occurrence ratio. In the procedure of traverse testing on elite lines and cultivars, Dena, Darab 2, Karkheh, CB227, CB338 and EBWYT-14 were resistant to all isolates in which there is probable presence of resistant genes in the seedling stage. Genes reported in all the regions can be used effectively for synthesis with the responsible and resistant genes in the completing plant stage.

Use of RAPD markers to characterize commercially grown rust resistant cultivars of sugarcane

The brown leaf rust caused by Puccinia melanaocephala (Syd. & P. Syd.) is a major cause of reduction in sugar production and withdrawal of sugarcane cultivars from growing fields. In The present study, the eight commercially grown sugarcane cultivar was characterized under natural inoculation and divided into two discrete groups i.e. four rust resistant and four rust susceptible. The extracted genomic DNA was subjected against RAPD (Random Amplified Polymorphic DNA) markers. After screening of decamers, 7 were picked for further analysis on the basis of polymorphism, which is the most important application of DNA markers. These decamers generated 21 trackable loci with the range of 400-2500 bp and 100% polymorphic loci were recorded genomic DNA of eight sugarcane cultivars. From 7 primers, 3 generated 5 specific loci in 4 sugarcane cultivars, which is a potential use of RAPD-PCR for identifying Saccharum spp. hybrids and clones. Primer G-06 generated only one locus 1200 bp in the rust susceptible cultivar NSG-59 while J-05 had produced two loci i.e. 400 bp and 1100 bp in rust resistant cultivars NSG-555 and CP-77-400 respectively. Primer L-18 generated 700 bp and 1400 bp loci in rust susceptible cultivar CoJS-84. The homology tree was constructed using DNAMAN software based on binary data set. During cluster analysis, we found two major groups of cultivars with different minor groups. This study will be useful to characterize rust resistance in sugarcane and could be extended for the development of SCAR (Sequence Characterized Amplified Region) marker, which is specific, reliable and reproducible marker.

PCR-based molecular markers linked to the leaf rust resistance gene Lr19 in different bread wheat cultivars

61 varieties of wheat collected in the gene fund of the Research Institute of Crop Husbandry were screened using SCAR-markers associated with the gene of resistance to brown leaf rust, Lr19. As a result of PCR analysis using SCS123 marker the 737 bp locus was detected in 48 genotypes. The expected fragment of the 688 bp was detected in 53 genotypes using the SCS253 marker. The results obtained using both markers indicate that the Lr19 gene is present on 7D chromosomes of 45 genotypes. The existence of the Lr19 gene has not been proven only for 5 from the 61 analyzed wheat genotypes.

Identification of the leaf rust resistance genes Lr9, Lr26, Lr28, Lr34, and Lr35 in a collection of Iranian wheat genotypes using STS and SCAR markers

Brown rust or leaf rust is one of the most important diseases of wheat occurring almost in all wheat-producing regions and reduces crop yield. In order to produce resistant cultivars, it is necessary to identify resistance genes in different germplasms and combine them in (a) suitable stock(s). To identify the presence of the leaf rust resistance genes using STS and SCAR markers, 83 Iranian wheat genotypes, Lr near-isogenic lines in Thatcher (positive controls), and the cultivar Thatcher (negative control) were used. After growing plants in the greenhouse, DNA was extracted by SDS method. Following that, polymerse chain reaction was performed for the markers of the resistance genes Lr9, Lr26, Lr28, Lr34, and Lr35 which amplified 1,100, 1,100, 378, 150, and 900 bp bands, respectively. Based on the results, the resistance genes Lr9 and Lr35 were only present in the positive controls. The resistance gene Lr26 was only detected in four cultivars; Arta, Pishtaz, Shiroodi, and Falat, and the gene Lr34 was present in six cultivars (Akbari, Bam, Tajan, Khazar 1, Sistan and Niknezhad). The Lr28 primer amplified a band of the same size in all genotypes even the negative control and therefore the presence/absence of this gene could not be validated. These results indicate the necessity for designing a specific primer for Lr28. In general, only the genes Lr26 and Lr34 were present in some genotypes. The genes Lr9 and Lr35 were not present in this collection and as based on rust surveys, no virulence has been detected for Lr9 and Lr28, so they could be transferred to suitable lines from donor sources.

Epidemiology and prediction of brown leaf rust of mulberry caused by Peridiopsora mori

Brown leaf rust (BLR) caused by Peridiopsora mori is one of the major foliar diseases of mulberry (Morus sp.) in the subtropical hills of eastern India. The disease appeared in first week of August and continued up to September with maximum severity in second and third week of September. The disease symptoms appeared at atmospheric temperature (27.00–20.07°C), relative humidity (92.14–82.43%), rainfall (11.20 cm) and rainy days (7) of the preceding week. Disease severity (>50 PDI) was observed at temperature (26.29–19.29°C), relative humidity (94.14–80.14%), rainfall (4.12 cm) and number of rainy days (2–3 days). Apparent rate of infection was found high at temperature (27.00–19.83°C), relative humidity (94.67–85.00%), rainfall (4.6 cm) and rainy days (2) of the preceding week. The correlation coefficient between disease severity and average meteorological factors of the preceding 7 days revealed that BLR disease severity showed significant negative correlation with minimum temperature. It was also revealed that contribution of maximum and minimum temperature 42.23% and 35.21%, maximum and minimum relative humidity (RH) 11.23% and 10.69% and rainfall and number of rainy days 0.11% and 0.50%, respectively towards development of BLR disease severity. Multiple regression analysis revealed that average of maximum and minimum temperatures and minimum RH of preceding 7 days were found to maximally influence BLR disease severity.

A study of the storage proteins in the introgression lines of common wheat (Triticum aestivum L. × T. timopheevii Zhuk.) Resistant to brown leaf rust

Storage proteins, prolamins, were studied in ten introgression lines of common wheat bred with involvement of Triticum timopheevii Zhuk. and five commercial hexaploid wheat cultivars. The lines are resistant to leaf rust. A comparative analysis of the storage proteins in the Triticum aestivum L. introgression lines and the parental forms allowed us to (1) detect the active genes of prolamins on the chromosomes homeologous groups 1 and 6 in the introgression lines of T. aestivum and T. timopheevii; (2) clarify their origin; (3) identify the chromosome attribution of the products; (4) estimate the degree of introgression and postulate the introgression mechanisms; and (5) predict the bread-making quality of these introgression lines.

Integration of plant growth-promoting rhizobacteria and chemical elicitors for induction of systemic resistance in mulberry against multiple diseases

In mulberry (Morus alba L.), various individual strains of plant growth-promoting rhizobacteria (PGPR) and synthetic analogs of naturally occurring plant activators have demonstrated their potential to elicit induced systemic resistance (ISR) against either brown leaf spot (Cercospora moricola) or leaf rust (Cerotelium fici) diseases. However, these biological and chemical elicitors have not been evaluated so far against multiple infections of both these diseases which commonly occur during the post-rainy season. The present study was therefore aimed to assess the capability of PGPR strains and chemical plant activators, as individual and in integration, in elicitation of ISR against multiple infections. Three PGPR strains, Azotobacter chroococcum strain Azc-3, Bacillus megaterium strain Bm-1 and Pseudomonas fluorescens strain Psf-4, and plant activators, acetyl-salicylic acid (ASA), sodium salicylate (NaS) and 4-amino-n-butyric acid (ABA) were selected for the study. Under in vitro tests, all the plant activators up to 2000 ppm concentration exhibited their compatibility with the PGPR strains tested. Upon assaying of elicitors with plant-pathosystem, disease suppression was significantly (p = 0.05) high with integrated application of PGPR strains and plant activators when compared to their individual applications. All the elicitors at individual application varied in their response to multiple infections with the plant age. However, integration of Azc-3 + ASA provided greater suppression to multiple infections of brown leaf spot and leaf rust diseases during the entire growth period of mulberry plants. Thus, this combination of biological and chemical elicitors holds great promise to provide an effective ecofriendly alternative to the toxic chemical fungicides presently recommended for the control of brown leaf spot and leaf rust diseases in mulberry.

Influence of alien chromosomes on the resistance of soft wheat to biotrophic fungal pathogens

The resistance of 77 disomic chromosome-addition and chromosome-substitution lines of soft wheat that had been created on the base of the Chinese Spring variety to Belorussian populations of powdery mildew and brown leaf rust is studied. The lines possess a chromosome pair introduced from 13 species of cereals as well as three amphiploids. New genes that express resistance to biotrophic fungal pathogens in chromosomes 2Ss and 5Ss from the Aegilops searsii species and chromosome 6Rm from the Secale montanum species were discovered. We do not exclude the possibility that the new resistance gene against powdery mildew is carried by chromosome 6S1 from the species Aegilops longissima (line No. 4), and that the new resistance gene against brown leaf rust is carried by chromosome 3E from the species Elytrigia elongata.

Management of Brown Leaf Rust, Puccinia recondita of Wheat Using Natural Products and Biocontrol Agents

Management of Brown Leaf Rust, Puccinia recondita of Wheat Using Natural Products and Biocontrol Agents