scholarly journals Genetic Resistance of Lactuca spp. against Fusarium oxysporum f. sp. lactucae Race 1

HortScience ◽  
2021 ◽  
pp. 1-13
Author(s):  
Jesse J. Murray ◽  
Gulnoz Hisamutdinova ◽  
Germán V. Sandoya ◽  
Richard N. Raid ◽  
Stephanie Slinski
Keyword(s):  
Fusarium Oxysporum ◽  
Durable Resistance ◽  
Management Strategies ◽  
Genetic Resistance ◽  
Segregation Ratio ◽  
Sources Of Resistance ◽  
Breeding Lines ◽  
Plant Introductions ◽  
Soil Pathogen ◽  
Race 1

Fusarium wilt of lettuce is caused by the pathogen Fusarium oxysporum f. sp. lactucae (Fol) and is a growing threat to global lettuce production. Fol was first detected in Florida in 2017 and was subsequently confirmed as race 1. Management strategies for this long-persisting soil pathogen are limited, time-consuming and expensive, and they may lack efficacy. Identifying diverse sources of genetic resistance is imperative for breeding adapted cultivars with durable resistance. The objectives of this study were to identify sources of resistance against a race 1 isolate of Fol in Florida, delineate the relationship between foliar and taproot symptoms, and investigate the inheritance of resistance and partial resistance in two F2 populations. Thirteen experiments were conducted in greenhouse and field locations to characterize the diversity of genetic resistance in the genus Lactuca. Leaf cultivars Dark Lollo Rossa and Galactic; romaine breeding lines 43007, 60182, and C1145; and iceberg breeding line 47083 consistently exhibited low foliar and taproot disease symptoms. Resistance was not identified among the wildtype Lactuca or primitive plant introductions (PI) in this study based on taproot symptoms. An additional test was conducted to study the segregation pattern of Fol resistance between one resistant and one susceptible accession (R × S) and one partial resistant and one susceptible accession (PR × S). The F2 population from ‘60182 × PI 358001-1’ fit the expected segregation ratio for a single recessive locus model, whereas the ratio for ‘Dark Lollo Rossa × PI 358001-1’ did not fit either recessive or dominant single locus models. These sources of resistance are potential candidates for developing commercial cultivars with multiple resistance loci against Fol race 1, especially for the Florida lettuce production system.

scholarly journals Resistance in Peanut Cultivars and Breeding Lines to Three Root-Knot Nematode Species

Plant Disease ◽  
2008 ◽  
Vol 92 (4) ◽  
pp. 631-638 ◽  
Author(s):  
W. B. Dong ◽  
C. C. Holbrook ◽  
P. Timper ◽  
T. B. Brenneman ◽  
Y. Chu ◽  
...  
Keyword(s):  
Durable Resistance ◽  
Nematode Species ◽  
Nematode Resistance ◽  
Root Knot Nematode ◽  
Sources Of Resistance ◽  
Breeding Lines ◽  
Sequence Characterized Amplified Region ◽  
Race 1 ◽  
Meloidogyne Spp ◽  
Peanut Cultivars

Three major species of root-knot nematode infect peanut: Meloidogyne arenaria race 1, M. hapla, and M. javanica race 3. Sources of resistance to all three nematodes are needed for developing novel peanut cultivars with broad resistance to Meloidogyne spp. Cultivars and breeding lines of peanut were evaluated for resistance to M. arenaria, M. hapla, and M. javanica in the greenhouse and in the laboratory. Twenty-six genotypes with some resistance to M. arenaria, M. javanica, or M. hapla were identified from 60 accessions based on average eggs per gram of root and gall index relative to a susceptible control. Among these, 14 genotypes were moderately to highly resistant to all three species, 5 genotypes were resistant to M. arenaria and M. javanica, 2 genotypes were resistant to M. javanica and M. hapla, 1 genotype was resistant M. arenaria alone, and 4 genotypes were resistant to M. hapla alone. Reproduction of M. arenaria on lines NR 0817, C724-19-11, and D108 was highly variable, indicating that these genotypes likely were heterogeneous for resistance. COAN, NemaTAM, C724-25-8, and the M. arenaria-resistant plants of C724-19-11 contained the dominant sequence-characterized amplified region marker (197/909) for nematode resistance. Results with the molecular markers indicate that the high resistance to M. arenaria in GP-NC WS 6 may be different from the resistance in COAN, NemaTAM, and C724-25-8. Resistance to M. arenaria was correlated with resistance to M. javanica in peanut, whereas resistance to M. hapla was not correlated with the resistance to either M. arenaria or M. javanica. The resistant selections should be valuable sources for pyramiding resistance genes to develop new cultivars with broad and durable resistance to Meloidogyne spp.

scholarly journals Resistance to Phytophthora nicotianae in Tobacco Breeding Lines Derived from Variety Beinhart 1000

Plant Disease ◽  
2013 ◽  
Vol 97 (2) ◽  
pp. 252-258 ◽  
Author(s):  
Kestrel McCorkle ◽  
Ramsey Lewis ◽  
David Shew
Keyword(s):  
Partial Resistance ◽  
Phytophthora Nicotianae ◽  
Sources Of Resistance ◽  
Black Shank ◽  
Breeding Lines ◽  
Stem Resistance ◽  
Race 1 ◽  
Low Levels ◽  
Dh Lines ◽  
Rapid Emergence

Black shank, caused by Phytophthora nicotianae, is managed primarily by host resistance. The rapid emergence of race 1 eliminated the usefulness of available complete resistance, leading breeders to search for new sources of resistance. Cigar tobacco ‘Beinhart 1000’ (BH) is highly resistant to all races of P. nicotianae. Doubled-haploid (DH) lines from a cross of BH and the susceptible ‘Hicks’ were evaluated for black shank resistance, and quantitative trait loci (QTL) on linkage groups (LGs) 4 and 8 accounted for >43% of the phenotypic variation in resistance. Forty-three DH lines and parents were evaluated, and genotypes with one or both QTL from BH on LGs 4 and 8 had increased incubation periods and decreased root rot but higher final inoculum levels than genotypes with neither QTL. A low level of stem resistance was observed in BH and DH lines with the QTL from BH on LG 4 but not LG 8. Low levels of leaf resistance were seen for Hicks, BH, and DH lines with both QTL from BH on LG 4 and 8. The partial resistance from BH has not been used commercially and may provide an increase in level of partial resistance in future tobacco varieties.

Allelic studies of new sources of scald (Rhynchosporium secalis Davis) resistance in barley

2003 ◽  
Vol 83 (4) ◽  
pp. 709-713 ◽  
Author(s):  
A. K. Singh ◽  
G. J. Scoles ◽  
R. A. Pickering ◽  
B. G. Rossnagel
Keyword(s):  
New Zealand ◽  
Genetic Resistance ◽  
Rhynchosporium Secalis ◽  
Sources Of Resistance ◽  
Hordeum Vulgare L ◽  
Breeding Programs ◽  
Breeding Lines ◽  
Disease Management Strategy ◽  
Key Words Barley ◽  
Resistant Lines

The use of genetic resistance is a desirable disease management strategy for controlling scald (Rhynchosporium secalis Davis) in barley (Hordeum vulgare L.); thus, it is essential to screen for new sources of resistance. The objectives of this study were to test the novelty of scald resistance in two barley lines from New Zealand, 145L2 and 4176/10/n/3/2/6, relative to a number of resistance sources available to western Canadian breeding programs, and to determine the source of this resistance. 145L2 and 4176/10/n/3/2/6 were resistant in New Zealand and in scald screening nurseries in Alberta, Canada, in 1998. 145L2 was crossed with 4176/10/n/3/2/6 and with four local resistant lines to determine allelic relationships between 145L2 resistance, 4176/10/n/3/2/6 resistance and the resistance(s) in the local lines. To determine the source of the resistance, all H. vulgare L. lines in the pedigree of the New Zealand lines were evaluated in the same nurseries. The resistance gene in 145L2 was not allelic to that in 4176/10/n/3/2/6 or the other barley lines tested. All lines in the pedigree of the two New Zealand lines were susceptible, suggesting that their resistance is derived from unknown parents in their pedigrees. These New Zealand lines provide new sources of scald resistance that can be incorporated into western Canadian breeding lines. Key words: Barley, scald, resistance

scholarly journals Resistance to Belly Rot in Cucumber Identified through Field and Detached-fruit Evaluations

1998 ◽  
Vol 123 (1) ◽  
pp. 78-84 ◽  
Author(s):  
Michael S. Uchneat ◽  
Todd C. Wehner
Keyword(s):  
Rhizoctonia Solani ◽  
Severe Disease ◽  
Genetic Resistance ◽  
Plant Introduction ◽  
Screening Methods ◽  
Sources Of Resistance ◽  
Partial Control ◽  
Breeding Lines ◽  
Horticultural Traits ◽  
Pickling Cucumbers

Belly rot, caused by the fungal pathogen Rhizoctonia solani Kühn., is a severe disease in many regions that produce cucumber (Cucumis sativus L.). Annual crop loss to belly rot is commonly 5% to 10%, but losses as high as 80% can occur in individual fields. There are no resistant cultivars, so fungicides are used to provide partial control. Genetic resistance in an acceptable cultivar would be more desirable and economical. Studies were conducted in Summers 1991 and 1992 to screen promising germplasm for belly rot resistance using field and detached-fruit screening methods. In 1991, 105 cultigens (cultivars, breeding lines, and plant introduction accessions) were evaluated for belly rot resistance. The tests were repeated in 1992 with 63 cultigens, including the most resistant cultigens identified in 1991 and appropriate controls. Several cultigens were identified as potential sources of resistance genes. Pickling cucumbers showing resistance included PI 197085, PI 271328, and an F4 selection of PI 197087 × PI 280096. Slicing cucumbers with resistance included `Marketmore 76' and the F1 of Gy 14 × PI 197087. Belly rot resistance was not correlated with other horticultural traits measured, including fruit type, skin type, spine color, and firmness. The resistant cultigens identified should be useful for developing cucumber cultivars with enhanced resistance to Rhizoctonia solani.

Characterization of universally avirulent strains of Phytophthora sojae

1992 ◽  
Vol 70 (6) ◽  
pp. 1175-1185 ◽  
Author(s):  
Ravindra G. Bhat ◽  
Arthur F. Olah ◽  
August F. Schmitthenner
Keyword(s):  
Hypersensitive Response ◽  
Segregation Ratio ◽  
Phytophthora Sojae ◽  
Avirulent Strain ◽  
Plant Introductions ◽  
Seedling Rot ◽  
Race 1 ◽  
Glycine Max L ◽  
Microbe Interactions ◽  
Or Gene

During the process of selfing race 1 of Phytophthora sojae M. J. Kaufmann & J. W. Gerdemann, a pathogen of soybean (Glycine max (L.) Merr.), a 3:1 segregation ratio of race 1 to avirulence was obtained. Avirulent strains were identical in appearance to races 1, 3, and 4 but induced the hypersensitive response when inoculated on the universally susceptible soybean cultivar Williams. A representative avirulent strain did not cause disease on cultivars with known Rps (resistance to P. sojae) genes or gene combinations, or on 33 plant introductions that were susceptible to race 1. The avirulent strain rotted apples in a manner similar to races 1 and 4 and did not rot soybean pods similar to avirulent races. It induced the hypersensitive response in soybean cotyledons, which then rotted after being placed in flooded conditions. Seventy-eight typical avirulent single-oospore strains of P. sojae and Phytophthora and Pythium spp. induced the hypersensitive response and elicited as much glyceollin in 'Williams' and 'Williams 79' as races 1, 3, and 4 elicited in 'Williams'. Four Phytophthora spp., which caused some seedling rot of soybean, elicited levels of glyceollin as high as races 1 and 3 in 'Williams 79'. It is concluded that the avirulent strains obtained from race 1 are either pathogenic and have host-specificity for soybean or universally avirulent strains that have lost all race-specific virulence genes. Key words: Phytophthora sojae, soybean, pathogens, races, hypersensitivity, plant – microbe interactions.

scholarly journals Germplasm Evaluation of Glycine max for Resistance to Fusarium solani, the Causal Organism of Sudden Death Syndrome

Plant Disease ◽  
1997 ◽  
Vol 81 (5) ◽  
pp. 515-518 ◽  
Author(s):  
G. L. Hartman ◽  
Y. H. Huang ◽  
R. L. Nelson ◽  
G. R. Noel
Keyword(s):  
Sudden Death ◽  
Fusarium Solani ◽  
Soybean Cyst Nematode ◽  
Sudden Death Syndrome ◽  
Growth Chamber ◽  
Soybean Plant ◽  
Sources Of Resistance ◽  
Causal Organism ◽  
Breeding Lines ◽  
Plant Introductions

Sudden death syndrome (SDS) is an important soybean disease that potentially can be controlled by host plant resistance. In this study, over 800 soybean plant introductions (PIs), lines, and cultivars were screened for resistance to Fusarium solani. Of 728 PIs from China, PI 567.374 had mean foliar SDS severities significantly (P = 0.05) lower than PI 520.733 (resistant check) in both growth-chamber and greenhouse tests. In addition, PIs 567.315, 567.441C, 567.650B, and 567.664 had mean SDS severity ratings significantly (P = 0.05) lower than PI 520.733 in a growth-chamber test. Of 16 soybean cyst nematode-resistant entries tested, 5 had values lower than the resistant check, PI 520.733, with cv. Hartwig significantly lower in the first trial. In trial two, no entries were lower than the resistant check, although cvs. Bell and Hartwig were not significantly different from PI 520.733. In another experiment, few soybean cultivars or experimental lines had SDS severity ratings lower than PI 520.733 in any one of three trials. Some of the newly acquired PIs from China that exhibited low foliar SDS severity ratings may provide the sources of resistance needed to develop new SDS-resistant soybean breeding lines and cultivars.

scholarly journals Sources of resistance to races R0 and R1 of Pseudomonas syringae PV. tomato - agent of bacterial speck on tomato

Genetika ◽  
2017 ◽  
Vol 49 (1) ◽  
pp. 139-149 ◽  
Author(s):  
Daniela Ganeva ◽  
Nevena Bogatzevska
Keyword(s):  
Pseudomonas Syringae ◽  
Morphological Characters ◽  
Sources Of Resistance ◽  
Breeding Lines ◽  
Bacterial Speck ◽  
Development Of Resistance ◽  
Gene Carriers ◽  
Race 1 ◽  
Tomato Breeding ◽  
Selection Of

Tomato breeding lines with fruit colour different from the traditional red colour were studied in order to search for sources of resistance to races R0 and R1 of Pseudomonas syringae pv. tomato. As a result of selection of healthy plants with hypersensitive response (HR), the resistance was stabilized and perspective lines gene-carriers of resistance to bacterial speck were chosen. Lines L1078 and L1083 with brown-red (black) coloured fruits and line L1130 with purple-red fruits possess a complex resistance to races R0 and R1. It was established that two of the lines with rose-coloured tomato fruits (L1088 and L584) were resistant to race 1 of P. syringae pv. tomato. These lines possessed valuable economic and morphological characters and they could be used in combinative and heterosis breeding for development of resistance to bacterial speck varieties.

Biplot evaluation of test environments and identification of lentil genotypes with durable resistance to fusarium wilt in India

2017 ◽  
Vol 68 (11) ◽  
pp. 1024 ◽  
Author(s):  
A. K. Parihar ◽  
Ashwani K. Basandrai ◽  
D. R. Saxena ◽  
K. P. S. Kushwaha ◽  
S. Chandra ◽  
...  
Keyword(s):  
Fusarium Wilt ◽  
Disease Incidence ◽  
Durable Resistance ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Breeding Lines ◽  
Disease Occurrence ◽  
Sources Of Variation ◽  
Testing Site ◽  
Natural Incidence

Fusarium wilt (caused by Fusarium oxysporum f. sp. lentis) is the most crucial limiting variable for decreasing yield levels of lentils (Lens culinaris Medik.) around the world. A set of 20 diverse lentil genotypes comprising breeding lines and released varieties was evaluated, along with susceptible controls, for resistance to fusarium wilt through natural incidence for two continuous years (2010–11 and 2011–12) in six diverse lentil-growing environments in India. Analysis of variance showed that the effect of genotype (G) and environment (E) for disease incidence was highly significant. Among the three sources of variation, the biggest contribution in disease occurrence was accounted for by environment (54.68%), followed by G × E interaction (17.32%). The high G × E variation necessitated assessment of the genotypes at different locations (environments). GGE biplot analysis of the studied genotypes revealed that genotype PL 101 and released cultivar L 4076 had low levels of disease incidence. The sources of resistance to fusarium wilt have great potential for use in lentil-breeding programs. Another biplot of relationships among environments demonstrated that, among the test locations, Sehore and Faizabad, were the most effective for differentiation of genotypes. On the basis of discriminating ability and representativeness, the Sehore location appeared an ideal testing site for natural incidence of F. oxysporum f. sp. lentis.

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 Cucurbit Powdery Mildew-resistant Bitter Gourd Breeding Lines Reveal Four Races of Podosphaera xanthii in Asia

HortScience ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 337-341 ◽  
Author(s):  
Narinder P.S. Dhillon ◽  
Supannika Sanguansil ◽  
Supornpun Srimat ◽  
Roland Schafleitner ◽  
B. Manjunath ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Smallholder Farmers ◽  
Bitter Gourd ◽  
Yield Potential ◽  
Podosphaera Xanthii ◽  
Asian Countries ◽  
Sources Of Resistance ◽  
Breeding Lines ◽  
Race 1 ◽  
Cucurbit Powdery Mildew

Bitter gourd (Momordica charantia L.) is a commercially and nutritionally important market vegetable in Asia cultivated mainly by smallholder farmers. Cucurbit powdery mildew (CPM) caused by Podosphaera xanthii (Px) is a nearly ubiquitous and serious fungal disease of bitter gourd. Five bitter gourd breeding lines (THMC 113, THMC 143, THMC 153, THMC 167, and THMC 170) were selected at the World Vegetable Center for resistance to a local isolate of Px in Kamphaeng Saen, Thailand. We evaluated the resistance potential of these five inbred lines against local isolates of Px at 12 locations in five Asian countries. Plants were inoculated with the respective local Px isolate 15 and 30 days after transplanting and additional Px-infected plants of the inoculated control were interplanted throughout each test. Plants were rated 60 days after transplanting for CPM reaction using a 0 (no evidence of infection) to 5 (>75% infection evident on individual leaves) disease severity scale. THMC 153 and THMC 167 were resistant to the local race of Px in all locations, whereas THMC 143 was observed resistant in all test locations except one in China. THMC 113 was resistant in each location except one in India. THMC 170 was susceptible in three locations in India. The multilocation tests revealed four unique Px races on bitter gourd in different Asian countries and sources of resistance for breeding CPM-resistant bitter gourd cultivars. Six strains of Px isolated from other cucurbits (Cucumis and Cucurbita) and representing five melon CPM races were unable to infect the susceptible M. charantia accession THMC 144 and the five resistant breeding lines, indicating pathotype differences between them and an isolate of M. charantia origin typed as race 1 on melon. THMC 143 and THMC 167, which originated from India, exhibited good yield potential in trials conducted in Thailand, Myanmar, Vietnam, and Bangladesh.

Sign in / Sign up

Export Citation Format

Share Document