scholarly journals CmPMRl and CmPMrs Were Responsible for Resistance to Powdery Mildew Caused by Podosphaera Xanthii Race 1 in Melon

2021 ◽  
Author(s):  
Haonan Cui ◽  
Chao Fan ◽  
Zhuo Ding ◽  
Xuezheng Wang ◽  
Lili Tang ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Candidate Gene ◽  
Cucumis Melo ◽  
Dominant Gene ◽  
Recessive Gene ◽  
Cellular Membrane ◽  
Epistatic Effect ◽  
Marker Assisted Breeding ◽  
Stem Resistance ◽  
Race 1

Abstract Cucumis melo L. is an economically important crop, the production of which is threatened by the prevalence of melon powdery mildew (PM) infections. We herein utilized the MR-1 (P1; resistant to PM) and M4-7 (P2; susceptible to PM) accessions to assess the heritability of PM (race 1) resistance in these melon plants. PM resistance in MR-1 leaves was linked to a dominant gene (CmPMRl), whereas stem resistance was under the control of a recessive gene (CmPMrs), with the dominant gene having an epistatic effect on the recessive gene. The CmPMRl gene was mapped to a 50 Kb interval on chromosome 12, while CmPMrs was mapped to an 89 Kb interval on chromosome 10. The CmPMRl candidate gene MELO3C002441 and the CmPMrs candidate gene MELO3C012438 were identified through sequence alignment, functional annotation, and expression pattern analyses of all genes within these respective intervals. MELO3C002441 and MELO3C012438 were both localized to the cellular membrane and were contained conserved NPR gene-like and MLO domains, respectively, which were linked to PM resistance. In summary, we identified patterns of PM resistance in the disease-resistant MR-1 melon cultivar, and conducted finally-mapping to identify two putative genes linked to resistance. Our results offer new genetic resources and markers guide the future molecular marker-assisted breeding of PM-resistant melon.

scholarly journals Genes for Resistance to Powdery Mildew Races 1 and 2U.S. in Melon PI 313970

HortScience ◽  
2003 ◽  
Vol 38 (4) ◽  
pp. 591-594 ◽  
Author(s):  
James D. McCreight
Keyword(s):  
Powdery Mildew ◽  
Cucumis Melo ◽  
Powdery Mildew Resistance ◽  
Dominant Gene ◽  
Recessive Gene ◽  
Sphaerotheca Fuliginea ◽  
Limited Data ◽  
Race 1 ◽  
Resistance Reaction ◽  
Greenhouse Tests

Powdery mildew is a major problem in melon (Cucumis melo L.) production worldwide. Three genes for resistance to Sphaerotheca fuliginea (Schlecht. ex Fr.) Poll. race 1 and race 2U.S. were identified in growth chamber and greenhouse tests in the cross of PI 313970 × `Top Mark'. A recessive gene conditioned resistance of true leaves to race 1. A recessive gene appeared to condition resistance of cotyledons to race 2U.S., although a second recessive gene may be involved. A semi-dominant gene conditioned resistance of true leaves to race 2U.S. Limited data suggested linkage of the recessive gene for resistance to race 1 and the semi-dominant gene for resistance to race 2U.S. The resistance reaction of PI 313970 to infection of true leaves by race 2U.S. included water-soaked spots and resistant blisters, but segregation data for the resistant blister reaction were inconclusive. Allelic relationships of these genes with previously reported melon powdery mildew resistance genes remain to be determined.

scholarly journals Genetic Mapping and Nucleotide Diversity of Two Powdery Mildew Resistance Loci in Melon (Cucumis melo)

2020 ◽  
Vol 110 (12) ◽  
pp. 1970-1979
Author(s):  
Cui Haonan ◽  
Ding Zhuo ◽  
Fan Chao ◽  
Zhu Zicheng ◽  
Zhang Hao ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Cucumis Melo ◽  
Nucleotide Diversity ◽  
Bulked Segregant Analysis ◽  
Durable Resistance ◽  
Recessive Gene ◽  
Segregation Ratio ◽  
Epistatic Effect ◽  
Fixation Index ◽  
Mendelian Segregation

Powdery mildew (PM) significantly and negatively affects the yield and quality of melon (Cucumis melo) worldwide. Race 2F is the predominant physiological race of the pathogen Podosphaera xanthii in many regions. We used accessions PMR 6 (P1; resistant to PM) and M1-7 (P2; susceptible to PM) to analyze the inheritance of resistance to PM (race 2F). The ratio between resistant and susceptible individuals fits a Mendelian segregation ratio of 13:3 in a total of 256 F2 individuals and 1:1 in BC1P2. The resistance to PM in PMR 6 was governed by two genes: a dominant (AA) gene with an epistatic effect and a recessive gene (bb). Only individuals with aaBB or aaBb genotypes were susceptible to PM. Two PM resistance loci, Pm2.1 and pm12.1, were mapped on chromosomes 2 and 12 by bulked segregant analysis and secondary mapping by quantitative trait loci analysis with 18 markers. A new marker-assisted selection system to identify melon genotypes resistant or susceptible to PM was developed and tested in 93 melon accessions. Nucleotide diversity (π) and fixation index (Fst) for the two PM resistance loci were estimated using resequencing data of 336 melons from three groups: C. melo subsp. agrestis, Cucumis melo subsp. melo, and the intermediate type. The lowest π was observed in C. melo ssp. agrestis, and the highest Fst value was between C. melo ssp. agrestis and C. melo ssp. melo. The findings provide a promising tool that can be used to accelerate breeding for durable resistance to PM.

scholarly journals Evidence for a Second RKN Resistance Gene in Peanut

2016 ◽  
Vol 43 (1) ◽  
pp. 49-51 ◽  
Author(s):  
W.D. Branch ◽  
T.B. Brenneman ◽  
J.P. Noe
Keyword(s):  
Genetic Model ◽  
Dominant Gene ◽  
Recessive Gene ◽  
Nematode Resistance ◽  
Root Knot Nematode ◽  
Vicia Villosa ◽  
Arachis Hypogaea L ◽  
Race 1 ◽  
Significant Yield ◽  
Very High

ABSTRACT Root-knot nematode (RKN), [Meloidogyne arenaria (Neal) Chitwood race 1] can result in highly significant yield losses in peanut (Arachis hypogaea L.) production. Fortunately, very high levels of RKN nematode resistance have been identified and incorporated from wild species into newly developed peanut cultivars. In 2011-12 at Tifton, GA, a field site was artificially inoculated with M. arenaria race 1. A susceptible cultivar was used to uniformly increase the peanut-specific race 1 nematode population during the summer and fall; whereas, hairy vetch (Vicia villosa Roth) was used for the same purpose each winter as a susceptible cover crop. During 2013 and 2014, space-planted F2 and F3 populations from cross combinations involving A. hypogaea susceptible × resistant parental lines derived from ‘COAN’ were evaluated, respectively. Several past inheritance studies had suggested a single dominant gene, Rma, controlled the resistance. However in this study, the occurrence of a second recessive gene (rma2) was also found to be involved in very high peanut RKN resistance. Inheritance data fit a 13:3 genetic model and confirmed an earlier report for two RKN-resistance genes (Rma1 and rma2) found in TxAG-6 and now COAN.

scholarly journals Inheritance of Resistance to Powdery Mildew Race 2 in Citrullus lanatus var. lanatus

HortScience ◽  
2013 ◽  
Vol 48 (10) ◽  
pp. 1227-1230 ◽  
Author(s):  
Antonia Y. Tetteh ◽  
Todd C. Wehner ◽  
Angela R. Davis
Keyword(s):  
Powdery Mildew ◽  
Citrullus Lanatus ◽  
Dominant Gene ◽  
Breeding Strategy ◽  
Dominance Model ◽  
Narrow Sense Heritability ◽  
Stem Resistance ◽  
Nonallelic Interactions ◽  
Race 2 ◽  
Moderate Resistance

Information on the mode of inheritance of powdery mildew resistance in watermelon is important for designing a breeding strategy for the development of new cultivars. Resistance in the watermelon accession PI 270545 was investigated by generation means analysis by crossing it with susceptible PI 267677. The analyses showed involvement of two genes, a recessive resistance gene, pmr-1, and a dominant gene for moderate resistance, Pmr-2. Resistance to powdery mildew in the leaf had a large dominance effect and a heritability of 71%. The additive-dominance model was inadequate in explaining variation in leaf resistance as revealed by the joint scaling test. However, nonallelic interactions could not be detected by the nonweighted six-parameter scaling test. For stem resistance, the additive-dominance model was adequate, and inheritance was controlled mainly by additive effects. A high narrow-sense heritability of 79% suggested that selection for stem resistance in early generations would be effective.

scholarly journals Genetic mapping and candidate gene analysis for melon resistance to Phytophthora capsici

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Pingyong Wang ◽  
Xiaojun Xu ◽  
Guangwei Zhao ◽  
Yuhua He ◽  
Chong Hou ◽  
...  
Keyword(s):  
Candidate Gene ◽  
Cucumis Melo ◽  
Bulked Segregant Analysis ◽  
Phytophthora Capsici ◽  
Expression Patterns ◽  
Dominant Gene ◽  
Resistance Mechanism ◽  
Receptor Kinase ◽  
Caps Marker ◽  
Mutation Site

AbstractPhytophthora blight is one of the most serious diseases affecting melon (Cucumis melo) production. Due to the lack of highly resistant germplasms, the progress on disease-resistant research is slow. To understand the genetics of melon resistance to Phytophthora capsici, an F2 population containing 498 individuals was developed by crossing susceptible line E31 to highly resistant line ZQK9. Genetic analysis indicated that the resistance in ZQK9 was controlled by a dominant gene, tentatively named MePhyto. Through bulked-segregant analysis (BSA-Seq) and chromosome walking techniques, the MePhyto gene was mapped to a 52.44 kb interval on chromosome 12. In this region, there were eight genes and their expression patterns were validated by qRT-PCR. Among them, one wall-associated receptor kinase (WAK) gene MELO3C002430 was significantly induced in ZQK9 after P. capsici inoculation, but not in E31. Based on the non-synonymous mutation site in MELO3C002430, a cleaved amplified polymorphic sequence (CAPS) marker, CAPS2430, was developed and this maker was co-segregated with MePhyto in both F2 population and a collection of 36 melon accessions. Thus MELO3C002430 was considered as the candidate gene and CAPS2430 was a promising marker for marker-assisted selection (MAS) in breeding. These results lay a foundation for revealing the resistance mechanism of melon to P. capsici.

scholarly journals Inheritance of Resistance to Bacterial Blight in 21 Cultivars of Rice

2003 ◽  
Vol 93 (2) ◽  
pp. 147-152 ◽  
Author(s):  
K. S. Lee ◽  
S. Rasabandith ◽  
E. R. Angeles ◽  
G. S. Khush
Keyword(s):  
Bacterial Blight ◽  
Oryza Sativa L ◽  
Dominant Gene ◽  
Recessive Gene ◽  
Inheritance Of Resistance ◽  
Race 1 ◽  
Group 2 ◽  
Race 2 ◽  
Moderate Resistance ◽  
Group 1

Genetic analysis for resistance to bacterial blight (Xanthomonas oryzae pv. oryzae) of 21 rice (Oryza sativa L.) cultivars was carried out. These cultivars were divided into two groups based on their reactions to Philippine races of bacterial blight. Cultivars of group 1 were resistant to race 1 and those of group 2 were susceptible to race 1 but resistant to race 2. All the cultivars were crossed with TN1, which is susceptible to all the Philippine races of X. oryzae pv. oryzae. F1 and F2 populations of hybrids of group 1 cultivars were evaluated using race 1 and F1 and F2 populations of hybrids of group 2 cultivars were evaluated using race 2. All the cultivars showed monogenic inheritance of resistance. Allelic relationships of the genes were investigated by crossing these cultivars with different testers having single genes for resistance. Three cultivars have Xa4, another three have xa5, one has xa8, two have Xa3, eight have Xa10, and one has Xa4 as well as Xa10. Three cultivars have new, as yet undescribed, genes. Nep Bha Bong To has a new recessive gene for moderate resistance to races 1, 2, and 3 and resistance to race 5. This gene is designated xa26(t). Arai Raj has a dominant gene for resistance to race 2 which segregates independently of Xa10. This gene is designated as Xa27(t). Lota Sail has a recessive gene for resistance to race 2 which segregates independently of Xa10. This gene is designated as xa28(t).

scholarly journals Genetic and Cytogenetic Studies of Stem Rust, Leaf Rust, and Powdery Mildew Resistances in Hope and Related Wheat Cultivars

1967 ◽  
Vol 20 (6) ◽  
pp. 1181 ◽  
Author(s):  
RA Mcintosh ◽  
NH Luig ◽  
EP Baker
Keyword(s):  
Powdery Mildew ◽  
Leaf Rust ◽  
Stem Rust ◽  
Dominant Gene ◽  
Recessive Gene ◽  
Stem Rust Resistance ◽  
Gene Interactions ◽  
Adult Plant ◽  
Wheat Cultivars ◽  
Cytogenetic Studies

Three linked genes responsible for resistance respectively to stem rust, to leaf rust, and to powdery mildew are located on chromosome 7B of Hope wheat. The gene for stem rust resistance, operative in seedling and adult plant stages, is recessive and is designated Br17. The incompletely dominant gene for resistance to leaf rust, designated Lr14, showed 18% recombination with sr17, whilst in two different crosses recombination estimates of 6�0 and 2�5%, respectively, were obtained for the recessive gene for mildew resistance and Br17. All three genes were found to be present in a high proportion of Hope and H�44 derivatives. The gene Br 1'7 is apparently ineffective in conferring resistance to North American and pre.1954 Australian stem rust strains. Its incorporation into several cultivars selected for resistance to these strains presumably resulted from gene interactions or linkage with genes for resistance to other diseases.

scholarly journals Development of Sweet Melon (Cucumis melo) Genotypes Combining High Sucrose and Organic Acid Content

2003 ◽  
Vol 128 (4) ◽  
pp. 537-540 ◽  
Author(s):  
Yosef Burger ◽  
Uzi Sa'ar ◽  
Asaph Distelfeld ◽  
Nurit Katzir ◽  
Yelena Yeselson ◽  
...  
Keyword(s):  
Acid Content ◽  
Cucumis Melo ◽  
Dominant Gene ◽  
Recessive Gene ◽  
Low Ph ◽  
Sugar Accumulation ◽  
Genetic Traits ◽  
High Acid ◽  
High Sugar ◽  
High Sucrose

The sweet cultivars of Cucumis melo are characterized by high sucrose levels, together with low acid levels in the mature fruit flesh. The trait of high sugar accumulation in C. melo fruit is determined by a single recessive gene, suc. High acid content, conferred by a single dominant gene, So, is found only in C. melo varieties that do not accumulate high levels of sugar and are used for nondessert purposes. We combined the genetic traits of high acid content (low pH) and high sugar levels by crossing the nonsweet, high acid C. melo var. flexuosus, `Faqqous' (So/So, Suc/Suc), with high sugar, low acid C. melo genotypes (so/so, suc/suc) and generating the recombinant genotype So/—, suc/suc. Segregating F2 populations derived from the cross between `Faqqous' and a standard high sugar, low acid line showed that the traits of high sugar and low pH were inherited independently of each other. The accumulation of acid and sugar in the developing fruit of a recombinant high acid, high sugar breeding line, A6, were also temporally independent, with acid accumulation preceding the rise in sucrose levels. The low pH of A6 was correlated with the developmental increase in titratable acidity and particularly of citric acid levels. The combination of increased acidity and high sugar provides the melons with a unique taste due to a sugar to acid ratio not present in sweet C. melo cultivars. These results are discussed in terms of the evolution under domestication of C. melo.

INHERITANCE OF VIRULENCE IN WHEAT LEAF RUST ON THE STANDARD DIFFERENTIAL WHEAT VARIETIES

1968 ◽  
Vol 10 (1) ◽  
pp. 24-32 ◽  
Author(s):  
D. J. Samborski ◽  
P. L. Dyck
Keyword(s):  
Leaf Rust ◽  
Dominant Gene ◽  
Recessive Gene ◽  
The Other ◽  
Wheat Leaf Rust ◽  
Single Recessive Gene ◽  
Wheat Varieties ◽  
Wheat Leaf ◽  
Recessive Genes ◽  
Race 1

Populations of self-fertilized cultures from races 1, 9, 15 and 161 of wheat leaf rust were studied for inheritance of virulence on the eight standard differential wheat varieties. Race 9 was homozygous at all loci tested while the other races segregated at a number of loci. Recessive genes controlled virulence on the varieties Malalkof (gene Lr1) and Hussar (gene Lr11) respectively. Virulence to Mediterranean and Democrat was governed by a single recessive gene in race 1 and a single dominant gene in race 161. One recessive gene in races 1 and 15 governed virulence to the various alleles of the Lr2 locus, while in race 161 a second dominant gene altered the expression of avirulence of this gene on Loros (Lr24). An additional recessive gene for virulence interacted with gene LrB in Carina and Brevit. It is not known whether the gene for virulence, which corresponds to a particular host gene for resistance, is the same in each race of leaf rust that was studied. All genes for virulence segregated independently.

Inheritance of resistance to a necrosis- and chlorosis-inducing isolate from Race 1 of Pyrenophora tritici-repentis in spring wheat

2001 ◽  
Vol 81 (3) ◽  
pp. 519-525 ◽  
Author(s):  
S. D. Duguid ◽  
A. L. Brûlé-Babel
Keyword(s):  
Triticum Aestivum ◽  
Conservation Tillage ◽  
Dominant Gene ◽  
Recessive Gene ◽  
Tan Spot ◽  
Inheritance Of Resistance ◽  
Pyrenophora Tritici Repentis ◽  
Ptr Toxa ◽  
Race 1 ◽  
Resistant Genotypes

Tan spot is a stubble-borne foliar disease of wheat (Triticum aestivum L.) caused by Pyrenophora tritici-repentis (Died.) Drechs. The potential for yield losses due to tan spot has increased with the adoption of conservation tillage practices. The main objective of this study was to determine the inheritance of resistance among seven wheat genotypes to the tan necrosis- and chlorosis-in ducing, race 1, isolate ASC1 (nec+ chl+), and the necrosis-inducing toxin, Ptr ToxA. Crosses were made between four resistant (Erik, ST6, 6B367, 6B1043) and three susceptible genotypes (Katepwa, BH1146, ST15). Parental, F1 and F2 populations were inoculated with ASC1 and infiltrated with Ptr ToxA under controlled environments. F2-derived F3 families were grown in the field and inoculated with ASC1. No reciprocal differences were observed. Resistance to the tan necrosis-inducing component of ASC1 and insensitivity to Ptr ToxA was controlled by a single recessive gene, whereas resistance to the chlorosis-inducing component of ASC1 was controlled by a single dominant gene. Genetic control of responses to each component (tan necrosis- or chlorosis-inducing) of ASC1 was independent. Lack of segregation among F2 progeny from crosses between resistant genotypes indicated that resistant genotypes carry at least one gene in common for resistance to ASC1. Key words: Triticum aestivum, Pyrenophora tritici-repentis, disease resistance, inheritance, Ptr ToxA, necrosis, chlorosis, toxin, tan spot, leaf spot

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