scholarly journals Identification of Resistance to Powdery Mildew in Chile Pepper

HortScience ◽  
2019 ◽  
Vol 54 (1) ◽  
pp. 4-7 ◽  
Author(s):  
Jack E. McCoy ◽  
Paul W. Bosland
Keyword(s):  
Powdery Mildew ◽  
Severe Infection ◽  
Capsicum Frutescens ◽  
Capsicum Chinense ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Chile Pepper ◽  
Commercially Important ◽  
Chile Peppers ◽  
Capsicum Chacoense

Powdery mildew [Leveillula taurica (Lév.) Arn] is a fungus causing epidemics on chile peppers (Capsicum sp.) worldwide. It was first observed in New Mexico in the late 1990s and has been a reoccurring issue. During the 2017 growing season, environmental conditions were highly favorable for powdery mildew development and severe infection was observed. This provided a unique opportunity to identify novel sources of resistance in Capsicum to powdery mildew. In the present study, the incidence and severity of powdery mildew was evaluated for 152 chile pepper accessions comprising different cultivars and species. Major differences in disease severity and incidence were observed among the accessions. Of the 152 accessions, 53 were resistant, i.e., received a disease index (DI) score of ≤1. When examining across Capsicum species, 16 Capsicum annuum accessions, all 8 Capsicum baccatum, all 21 Capsicum chinense, 5 of 6 Capsicum frutescens, the Capsicum chacoense accession, and the Capsicum rhomboideum accession were resistant. These results provide several accessions with resistance that can be used in breeding programs. Especially important are the C. annuum resistant accessions, as this resistance can be more quickly incorporated into commercially important C. annuum cultivars as compared with interspecific hybridizations.

Identification of Resistance to Powdery Mildew in Publicly Available Male Hop Germplasm

2018 ◽  
Vol 19 (3) ◽  
pp. 258-264
Author(s):  
David H. Gent ◽  
Briana J. Claassen ◽  
Megan C. Twomey ◽  
Sierra N. Wolfenbarger
Keyword(s):  
United States ◽  
Powdery Mildew ◽  
Pacific Northwest ◽  
Western United States ◽  
R Genes ◽  
Sources Of Resistance ◽  
Department Of Agriculture ◽  
Breeding Programs ◽  
The Pacific ◽  
The U.S

Powdery mildew (caused by Podosphaera macularis) is one of the most important diseases of hop in the western United States. Strains of the fungus virulent on cultivars possessing the resistance factor termed R6 and the cultivar Cascade have become widespread in the Pacific Northwestern United States, the primary hop producing region in the country, rendering most cultivars grown susceptible to the disease at some level. In an effort to identify potential sources of resistance in extant germplasm, 136 male accessions of hop contained in the U.S. Department of Agriculture collection were screened under controlled conditions. Iterative inoculations with three isolates of P. macularis with varying race identified 23 (16.9%) accessions with apparent resistance to all known races of the pathogen present in the Pacific Northwest. Of the 23 accessions, 12 were resistant when inoculated with three additional isolates obtained from Europe that possess novel virulences. The nature of resistance in these individuals is unclear but does not appear to be based on known R genes. Identification of possible novel sources of resistance to powdery mildew will be useful to hop breeding programs in the western United States and elsewhere.

Pathogenic variation in Australian isolates of Mycosphaerella graminicola

1995 ◽  
Vol 46 (5) ◽  
pp. 921 ◽  
Author(s):  
B Ballantyne ◽  
F Thomson
Keyword(s):  
New South ◽  
Severe Infection ◽  
Mycosphaerella Graminicola ◽  
Limited Disease ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Host Pathogen Interaction ◽  
South Wales ◽  
Pathogenic Variation ◽  
Linear Modelling

Seven isolates of Mycosphaerella graminicola gave a range of infection patterns when inoculated onto 20 wheat testers in glasshouse tests. Linear modelling and the biplot technique indicated host-pathogen interaction, hence evidence for physiologic specialization. Two isolates from Western Australia (WA) gave only limited disease on the cultivar Egret which is field resistant in WA. The cvv. Heron and Robin which are related to each other and to Egret also showed limited disease with the WA isolates and with certain NSW cultures. Five New South Wales (NSW) isolates produced moderate to severe infection on this cultivar which is field susceptible in NSW. Among the bread wheats used as sources of resistance in southern NSW only one, M1696, remained healthy with all isolates; nine other lines developed little disease with most isolates but more infection with other isolates, especially two isolates isolated from the field in severe epidemics. There was agreement between replicates within and between experiments. The relevance of these findings to breeding programs is discussed.

scholarly journals Evaluation and Pre-selection of New Grapevine Genotypes Resistant to Downy and Powdery Mildew, Obtained by Cross-Breeding Programs in Spain

2021 ◽  
Vol 12 ◽  
Author(s):  
Leonor Ruiz-García ◽  
Pilar Gago ◽  
Celia Martínez-Mora ◽  
José Luis Santiago ◽  
Diego J. Fernádez-López ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Powdery Mildew ◽  
Simple Sequence Repeat ◽  
Selection Process ◽  
Sequence Repeat ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Phenotypic Resistance ◽  
Simple Sequence ◽  
Selection Of

The need to develop an environmentally friendly, sustainable viticulture model has led to numerous grapevine improvement programmes aiming to increase resistance to downy and powdery mildew. The success of such programmes relies on the availability of protocols that can quantify the resistance/susceptibility of new genotypes, and on the existence of molecular markers of resistance loci that can aid in the selection process. The present work assesses the degree of phenotypic resistance/susceptibility to downy and powdery mildew of 28 new genotypes obtained from crosses between “Monastrell” and “Regent.” Three genotypes showed strong combined resistance, making them good candidates for future crosses with other sources of resistance to these diseases (pyramiding). In general, laboratory and glasshouse assessments of resistance at the phenotype level agreed with the resistance expected from the presence of resistance-associated alleles of simple sequence repeat (SSR) markers for the loci Rpv3 and Ren3 (inherited from “Regent”), confirming their usefulness as indicators of likely resistance to downy and powdery mildew, respectively, particularly so for downy mildew.

scholarly journals ‘Bhut Jolokia’—The World's Hottest Known Chile Pepper is a Putative Naturally Occurring Interspecific Hybrid

HortScience ◽  
2007 ◽  
Vol 42 (2) ◽  
pp. 222-224 ◽  
Author(s):  
Paul W. Bosland ◽  
Jit B. Baral
Keyword(s):  
Species Identification ◽  
Dna Markers ◽  
Interspecific Hybrid ◽  
Genetic Introgression ◽  
Capsicum Frutescens ◽  
Randomly Amplified Polymorphic Dna ◽  
Capsicum Chinense ◽  
Chile Pepper ◽  
Naturally Occurring ◽  
Bhut Jolokia

In replicated trials at Las Cruces, N.M., the Scoville heat units (SHUs) of ‘Bhut Jolokia’, a chile pepper from Assam, India, reached one million SHUs. Morphologic characters revealed that ‘Bhut Jolokia’ is a Capsicum chinense Jacq. cultivar. Molecular analysis with randomly amplified polymorphic DNA markers confirmed the species identification and, interestingly, revealed that there may have been genetic introgression from Capsicum frutescens L. into ‘Bhut Jolokia’.

scholarly journals Potential Sources of Resistance to Cucurbit Powdery Mildew in U.S. Plant Introductions of Bottle Gourd

HortScience ◽  
2008 ◽  
Vol 43 (5) ◽  
pp. 1359-1364 ◽  
Author(s):  
Chandrasekar S. Kousik ◽  
Amnon Levi ◽  
Kai-Shu Ling ◽  
W. Patrick Wechter
Keyword(s):  
Powdery Mildew ◽  
The United States ◽  
Bottle Gourd ◽  
Severe Damage ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Plant Introductions ◽  
Race 1 ◽  
Moderate Resistance ◽  
Greenhouse Tests

Powdery mildew (Podosphaera xanthii) can cause severe damage to cucurbit crops grown in open fields and greenhouses. In recent years, there has been an increased interest in the United States in grafting watermelon plants onto various cucurbit rootstocks. Bottle gourd plants (Lagenaria siceraria) are being used throughout the world as rootstocks for grafting watermelon. Although gourd plants are beneficial, they may still be susceptible hosts to various soilborne and foliar diseases. Bottle gourd plant introductions (PI) resistant to diseases and pests can be a valuable source of germplasm in rootstock breeding programs. We evaluated 234 U.S. PIs of L. siceraria for tolerance to powdery mildew in two greenhouse tests. Young seedlings were inoculated by dusting powdery mildew spores of melon race 1 on the cotyledons. Plants were rated 2 weeks after inoculation using a 1 to 9 scale of increasing disease severity. Although none of the L. siceraria PIs were immune to powdery mildew, several PIs had significantly lower levels of powdery mildew severity compared with susceptible watermelon cultivar Mickey Lee. The experiment was repeated with 26 select PIs on whole seedlings and cotyledon disks. Significant variability in the level of resistance to powdery mildew on plants within PI was observed. Moderate resistance in several PIs to powdery mildew was confirmed. PI 271353 had consistently lower ratings in the various tests and can be considered the most resistant to P. xanthii race 1 among the L. siceraria accessions evaluated in this study. A few other PIs with moderate resistance to powdery mildew included PI 271357, PI 381840, and PI 273663. These results suggest that novel sources of resistance could be developed by careful selection and screening of several of the PIs with moderate resistance described in our study.

scholarly journals New sources of powdery mildew resistance among winter bread wheat for adjusting the breeding immunological programs in the Agricultural Research Center “Donskoy”

2021 ◽  
pp. 82-87
Author(s):  
Т. G. Derova ◽  
N. V. Shishkin ◽  
О. S. Kononenko
Keyword(s):  
Powdery Mildew ◽  
Winter Wheat ◽  
Agricultural Research ◽  
Research Center ◽  
Artificial Infection ◽  
Sources Of Resistance ◽  
Wheat Varieties ◽  
Breeding Programs ◽  
Winter Bread Wheat ◽  
Resistant Varieties

Systematic work on the development of winter wheat varieties possessing resistance to a complex of the most harmful diseases has been carried out in the Agricultural Research Center “Donskoy” since the early 1970s. During this period, there has been created a large number of varieties that possess resistance to 3–4 diseases in conditions of infectious backgrounds of pathogens. Due to the analysis of varieties, there was identified a small number of varieties resistant to powdery mildew. Powdery mildew, caused by the fungus Blumeria graminis (DC) Speer, annually occurs on wheat, affecting all aboveground plant organs. Earlier the FSBSI “ARC “Donskoy” developed and widely cultivated the medium-resistant varieties ‘Tanais’ (2006), ‘Nakhodka’ (2015), ‘Etyud’, ‘Shef’, ‘Lilit’ (2016), ‘Volnitsa’ (2017), ‘Polina’, Yubiley Dona’ , ‘Podarok Krymu’ (2018), ‘Niva Dona’ (2019). In recent years, breeders have developed such varieties with high resistance to the pathogen as ‘Donskaya Step’ (2016), ‘Premiera’, ‘Univer’ (2018), ‘Priazovye’, ‘Zolotoy Kolos’ (2020). But the breeding process of varieties for resistance to powdery mildew is difficult, since it is explained by the small number of effective resistance genes and their sources. Therefore, the purpose of the current study was to identify new sources of resistance to the pathogen. Under the conditions of artificial infection, during last 10 years there was conducted a testing of 302 varieties and samples of winter wheat of domestic and foreign breeding. There have not been identified immune varieties. There was identified a small percentage (15.2) of varieties that were resistant to the pathogen. Among the Russian varieties they were ‘L 3191 k-5-8’, ‘Akhmat’, ‘Alievich’, ‘Barier’, ‘Ulyasha’, ‘Knyaginya Olga’, which were not attacked by the disease over the years of testing. Among foreign varieties, the varieties ‘Bombus’, ‘Sailor’ (France), ‘Etana’, ‘Rotax’, ‘KVS-Emil’ (Germany), ‘Fidelius’ (Austria), ‘MV 09-04’ (Hungary) were identified as the best ones in their resistance to powdery mildew. All identified sources of resistance have been recommended in breeding programs for immunity.

scholarly journals Sources of Resistance to Powdery Mildew in Barley Landraces from Turkey

Agriculture ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1017
Author(s):  
Jerzy H. Czembor ◽  
Elżbieta Czembor
Keyword(s):  
Powdery Mildew ◽  
Resistance Genes ◽  
Sources Of Resistance ◽  
Seedling Resistance ◽  
Breeding Programs ◽  
Breeding Lines ◽  
Resistant Lines ◽  
Highly Effective ◽  
Barley Landraces

Powdery mildew on barley, caused by the pathogen Blumeria graminis f. sp. hordei, occurs worldwide and can result in severe yield loss. Germplasm of barley, including landraces, commercial cultivars, wild relatives and breeding lines are stored in more than 200 institutions. There is a need for characterization of this germplasm in terms of resistance to biotic and abiotic stresses. This is necessary in order to use specific accessions in breeding programs. In the present study, 129 barley landraces originated from Turkey and provided by the ICARDA genebank were tested for resistance to powdery mildew. Seedling resistance tests after inoculation with 19 differentiated isolates of B. graminis f. sp. hordei were used to postulate the presence of resistance genes. From the 129 landraces studied, plants of 19 (14.7%) of them showed resistance to infection with powdery mildew. Based on preliminary tests from these 19 landraces, 25 resistant single plant lines were selected for testing with differential powdery mildew isolates. Seven lines were resistant to all 19 isolates used. However, only one line (5583-1-4) showed resistance scores of zero against all isolates used. It is likely that this line possesses unknown, but highly effective genes for resistance. In five resistant lines it was not possible to postulate the presence of specific resistance genes. In 19 lines the presence of the genes Mlp, Mlk, Mlh, Mlg, Ml(CP), Mlat, Mla3, Mla6, Mla7 and Mla22 were postulated. These new sources of highly effective powdery mildew resistance in barley landraces from Turkey could be successfully used in breeding programs.

RESISTANCE TO MILDEW OF SELECTION FAMILY OF RED CURRANT THE BELAYA POTAPENKO × № 1426-21-80

1970 ◽  
pp. 38-40
Author(s):  
O. O. Kalinina ◽  
O. D. Golyaeva ◽  
O. V. Panfilova ◽  
А. V. Pikunova
Keyword(s):  
Powdery Mildew ◽  
Field Resistance ◽  
Disease Development ◽  
Artificial Infection ◽  
Sources Of Resistance ◽  
Climate Conditions ◽  
High Productivity ◽  
Local Soil ◽  
The Family ◽  
Red Currant

Powdery mildew is one of the most harmful fungal diseases that causes economically significant damage to berry plantations. The disease is common in all areas of currant cultivation in the Russian Federation. In this regard, in modern conditions of intensive berry growing, the problem of breeding cultivars that are highly resistant to diseases and pests becomes urgent. Breeders have a difficult task to combine the adaptive potential of the cultivar with its annual high productivity and resistance to biotic environmental factors. When studying the adaptability of introduced cultivars of red currant and selected forms of the Institute to local soil and climate conditions, the following cultivars were identified as sources of economic and useful characteristics and involved in selection: ‘Belaya Potapenko’ as a complex source of resistance powdery mildew and high marketable and taste qualities of berries; SS 1426-21-80 as a source of high productivity and long racemes (raceme length 11-13 cm; up to 20 berries in the raceme). On their base the selection family of red currant has been developed: Belaya Potapenko × ♂SS 1426-21-80. The study of data on the destruction of hybrid seedlings of the selection family by powdery mildew showed that in epiphytotic conditions, the percentage of intensity of the disease development varies over the periods of screening from 0.2% in May to 20.4% in June. Such indicators served as a prerequisite for conducting a comparative test of breeding material in the field under artificial infection with powdery mildew. After artificial infection on the background of epiphytosis, the rate of intensity of the disease development increased slightly and amounted to 35.6% for the family. There were 30 highly resistant seedlings in the family, 10 of which have remained stable and highly resistant since 2018. In these plants we can assume the presence of the so-called field resistance, controlled by polygens, each of which does not give a visible effect of stability, but with different combinations determines one or another of its degree. Highly resistant seedlings will be used in further breeding studies to identify new sources of resistance to powdery mildew.

Achievements in breeding and main directions for improving black currant adssortment in Federal Horticultural Research Center for Breeding, Agrotechnology and Nursery

2021 ◽  
Vol 67 ◽  
pp. 18-28
Author(s):  
F. F. Sazonov
Keyword(s):  
Powdery Mildew ◽  
Base Station ◽  
Research Center ◽  
Sources Of Resistance ◽  
Black Currant ◽  
Genetic Origin ◽  
State Register ◽  
Leaf Spots ◽  
Breeding Research ◽  
Horticultural Research

The article presents the main results of twenty years of research carried out at the Federal Horticultural Research Center for Breeding, Agrotechnology and Nursery (Kokino Base Station) on the search and creation of various genetic origin genotypes and the possibility of their use in further breeding work on black currants. The created genetic sources of resistance to American powdery mildew, leaf spots (canker, septoria, cercosporosis), large-fruited, berries’ high vitamin С content, fruit strength, plant productivity are presented: 7-37-2 (Litvinovskaya × Dar Smolyaninovoy), 37-27-4/05 (Debryansk, free pollination), 63-35-1 (Lentyay × Debryansk), 68-03-1 (Charodey × Yadryonaya), 5-66-5 (Dobrynya, free pollination), 13-51-1 (Shalunya, free pollination), 33-27-1 (Strelets × Selechenskaya 2) etc. As a result of breeding research, 12 black currant varieties have been created, eight of which (Bryanskiy Agate, Debryansk, Mif, Vera, Gamayun, Strelets, Charodey, Barmaley) are included in the State Register of Breeding Achievements, approved for using.

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