scholarly journals Variation for Resistance to Verticillium Wilt in Lettuce (Lactuca sativa L.)

Plant Disease ◽  
2007 ◽  
Vol 91 (4) ◽  
pp. 439-445 ◽  
Author(s):  
Ryan J. Hayes ◽  
Gary E. Vallad ◽  
Qing-Ming Qin ◽  
Rebecca C. Grube ◽  
Krishna V. Subbarao
Keyword(s):  
Verticillium Wilt ◽  
Lactuca Sativa ◽  
Field Experiments ◽  
Cost Effective ◽  
Resistant Cultivars ◽  
Lactuca Sativa L ◽  
Cost Effective Method ◽  
Constant Resistance ◽  
Race 1 ◽  
Race 2

Host resistance offers the most cost-effective method of Verticillium wilt control in lettuce (Lactuca sativa). In 2004 and 2005, 107 and 22 lettuce cultivars, respectively, were screened for resistance in a field infested with Verticillium dahliae, and disease progress on resistant and susceptible cultivars was determined. Greenhouse experiments were conducted to evaluate 16 cultivars for resistance to a race 1 and a race 2 isolate. Significant differences for resistance were observed within cultivated lettuce. In susceptible cultivars, disease levels increased through the season, whereas disease in resistant cultivars remained constant. Resistance in greenhouse tests was dependant upon the race used. Seven cultivars were resistant to race 1, whereas all were susceptible to race 2. Cultivar reactions to race 1 in greenhouse and field experiments were correlated, indicating the utility of greenhouse evaluations. The identification of resistance in diverse lettuce types is beneficial to the breeding process. However, because of the existence of resistance-breaking race 2 isolates, this resistance may not be durable. Alternatively, targeted releases of race-1-resistant cultivars to fields with only race 1 pathogen genotypes may extend the life of these cultivars.

scholarly journals Development of PCR-Based Marker for Resistance to Fusarium wilt Race 2 in Lettuce (Lactuca Sativa L.)

2021 ◽  
Author(s):  
kousuke seki ◽  
kenji komatsu ◽  
masahiro hiraga ◽  
keisuke tanaka ◽  
yuichi uno ◽  
...  
Keyword(s):  
Fusarium Wilt ◽  
Fine Mapping ◽  
Lactuca Sativa ◽  
Resistance Phenotype ◽  
Resistant Cultivars ◽  
Breeding Technique ◽  
Lactuca Sativa L ◽  
Race 2 ◽  
Selection Of

Abstract Resistance to multiple races of Fusarium wilt is considered a critical trait for lettuce (Lactuca sativa L.) cultivars, as it is directly related to grower profitability in Japan. We analyzed F2 individuals obtained from a cross between ‘VI185’ (resistance to race 2) and ‘ShinanoGreen’ (susceptible to race 2), and applied a bioassay to the F3 population using the race 2 pathogen. ddRAD-seq analysis showed that a single semi-dominant locus on LG1 (qFOL1.2) controls resistance, and that the genotype of a RAD-marker designated as LG1_v8_117.181Mbp showed complete co-segregation with the resistance phenotype based on the F2 population. Fine mapping by PCR-based markers further revealed that qFOL1.2 were located in the position of 116.468-117.974Mbp. The 42 cultivars were evaluated for the genotypes and phenotypes using the PCR-based makers designed at this region. As a result of genotyping, all of the susceptible cultivars had the same genotype in this region, but the resistant cultivars had the diversity in the genotype. Notably, the genotype of the PCR-based marker designated as LG1_v8_116.506Mbp was consistent across the 25 resistant cultivars. Thus, we reasoned that LG1_v8_116.506Mbp was a broadly useful marker for selection of race 2-resistance. Our results provide additional breeding technique for resistance to race 2, and can accelerate pyramiding of resistance loci to multiple races of fusarium wilt.

scholarly journals Host Range of Verticillium isaacii and Verticillium klebahnii from Artichoke, Spinach, and Lettuce

Plant Disease ◽  
2015 ◽  
Vol 99 (7) ◽  
pp. 933-938 ◽  
Author(s):  
Suraj Gurung ◽  
Dylan P. G. Short ◽  
Xiaoping Hu ◽  
German V. Sandoya ◽  
Ryan J. Hayes ◽  
...  
Keyword(s):  
New Species ◽  
Host Range ◽  
Disease Severity ◽  
Verticillium Wilt ◽  
Agricultural Soils ◽  
Phylogenetic Analyses ◽  
Greenhouse Experiment ◽  
Vascular Wilt ◽  
Race 1 ◽  
Race 2

Verticillium is a genus that includes major vascular wilt pathogens. Recently, multilocus phylogenetic analyses of the genus identified five new species, including Verticillium isaacii and V. klebahnii, both of which occur in agricultural soils in coastal California and have been isolated from asymptomatic and diseased spinach and lettuce plants. Little data are available regarding their pathogenicity and virulence on a broader range of crops important to the region. Four isolates each of V. isaacii and V. klebahnii along with two reference isolates of V. dahliae races 1 and 2 were inoculated on eight crops (artichoke, cauliflower, eggplant, lettuce, pepper, tomato, spinach, and strawberry) in a greenhouse experiment. After 8 weeks, plants were assessed for disease severity to determine the relative host ranges of Verticillium isolates. Additionally, 13 lettuce lines resistant to race 1 and partially resistant to race 2 of V. dahliae were screened against V. isaacii and V. klebahnii to evaluate their responses. Three of four V. isaacii and four of four V. klebahnii isolates tested were nonpathogenic on all crops tested except those indicated below. One V. isaacii isolate caused wilt on artichoke and ‘Salinas’ lettuce and most isolates of both species caused varying degrees of Verticillium wilt on strawberry. Lettuce lines resistant to V. dahliae race 1 and partially resistant to V. dahliae race 2 also exhibited resistance to all of the isolates of V. isaacii and V. klebahnii. Thus, at least some isolates in the populations of V. isaacii and V. klebahnii have the potential to become significant pathogens of coastal California crops. However, resistance developed against V. dahliae also offers resistance to the pathogenic isolates of both species, at least in lettuce.

scholarly journals Genetic Control of Resistance to Tan Necrosis Induced by Pyrenophora tritici-repentis, Races 1 and 2, in Spring and Winter Wheat Genotypes

2005 ◽  
Vol 95 (2) ◽  
pp. 172-177 ◽  
Author(s):  
P. K. Singh ◽  
G. R. Hughes
Keyword(s):  
Winter Wheat ◽  
Genetic Control ◽  
Recessive Gene ◽  
Tan Spot ◽  
Wheat Genotypes ◽  
Resistant Cultivars ◽  
Pyrenophora Tritici Repentis ◽  
Lesion Type ◽  
Race 1 ◽  
Race 2

The symptoms of tan spot of wheat, caused by Pyrenophora triticirepentis, include a tan necrosis component and an extensive chlorosis component. Since tan spot has become the major component of the leafspotting disease complex of wheat in western Canada, the need for resistant cultivars has increased. This study was conducted to determine whether the resistance to tan spot found in a diverse set of spring and winter wheat genotypes was due to resistance genes not previously reported. The genetic control of resistance to necrosis induced by P. triticirepentis race 1 and race 2 was determined, under controlled environmental conditions, for spring wheat genotypes Erik and 86ISMN 2137 and winter wheat genotypes Hadden, Red Chief, and 6B-365. Plants were inoculated at the two-leaf stage and disease reaction was assessed based on lesion type. Tests of the F1 and F2 generations, and of F2:3 and F2:8 families, indicated that one recessive gene controlled resistance to the necrosis component of tan spot caused by both race 1 and race 2 in each cross studied. Lack of segregation in crosses between the resistant cultivars indicated that the resistance gene was the same in all of the cultivars.

scholarly journals Characterization of Race-Specific Interactions Among Isolates of Verticillium dahliae Pathogenic on Lettuce

2006 ◽  
Vol 96 (12) ◽  
pp. 1380-1387 ◽  
Author(s):  
Gary E. Vallad ◽  
Qing-Ming Qin ◽  
Rebecca Grube ◽  
Ryan J. Hayes ◽  
Krishna V. Subbarao
Keyword(s):  
Verticillium Dahliae ◽  
Field Experiments ◽  
Sequence Data ◽  
Intergenic Spacer ◽  
Distinct Subgroup ◽  
Race 1 ◽  
Race 2 ◽  
The 1960S ◽  
Significant Disease

Verticillium wilt, caused by Verticillium dahliae, poses a major threat to lettuce (Lactuca sativa) production in California. Incorporation of resistance into commercial lettuce cultivars offers the least expensive technique of sustaining production in infested areas. To test the breadth of the resistance identified in field experiments, a pair of susceptible (‘Salinas’ and ‘Sniper’) and resistant (‘La Brillante’ and ‘Little Gem’) lettuce cultivars were used as differentials and individually inoculated with 29 isolates of V. dahliae and two isolates of V. albo-atrum from several hosts, including lettuce, in replicated greenhouse experiments. The reactions of the four cultivars were determined based on the disease severity at maturity. None of the V. albo-atrum isolates or V. dahliae isolates from cruciferous hosts caused significant disease on lettuce. Both Salinas and Sniper were susceptible to many isolates of V. dahliae (21 of 23) from noncruciferous hosts, and the isolates varied in their overall virulence. However, of these, only three isolates caused significant disease on the resistant cvs. La Brillante and Little Gem. These three isolates also were distinct from the other V. dahliae isolates based on sequence data from the intergenic spacer (IGS) region of the nuclear ribosomal RNA gene, suggesting that they form a phylogenetically distinct subgroup that differs in virulence toward specific lettuce genotypes. Accordingly, isolates of V. dahliae virulent on all tested cultivars, including the resistant La Brillante and Little Gem, were designated as race 2, whereas those virulent only on the susceptible Salinas and Sniper were designated as race 1. Although a range of virulence among isolates has been described in other hosts, this is the first description of distinct virulence phenotypes in V. dahliae since a similar race structure was described in tomato in the 1960s.

scholarly journals Analysis of RAPD and AFLP markers linked to resistance to Fusarium oxysporum f. sp. lactucae race 2 in lettuce (Lactuca sativa L.)

Euphytica ◽  
2012 ◽  
Vol 187 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Daisuke Aruga ◽  
Nobuaki Tsuchiya ◽  
Hideo Matsumura ◽  
Etsuo Matsumoto ◽  
Nobuaki Hayashida
Keyword(s):  
Fusarium Oxysporum ◽  
Lactuca Sativa ◽  
Aflp Markers ◽  
Lactuca Sativa L ◽  
Race 2

scholarly journals Nondefoliating and Defoliating Strains from Cotton Correlate with Races 1 and 2 of Verticillium dahliae

Plant Disease ◽  
2015 ◽  
Vol 99 (12) ◽  
pp. 1713-1720 ◽  
Author(s):  
Xiao-Ping Hu ◽  
Suraj Gurung ◽  
Dylan P. G. Short ◽  
German V. Sandoya ◽  
Wen-Jing Shang ◽  
...  
Keyword(s):  
Verticillium Wilt ◽  
Verticillium Dahliae ◽  
Reference Strain ◽  
The United States ◽  
Specific Primers ◽  
Differential Cultivars ◽  
Race 1 ◽  
Polymerase Chain ◽  
Race 2 ◽  
Important Disease

Verticillium wilt, caused by Verticillium dahliae, is an important disease of cotton worldwide. Isolates of V. dahliae can be characterized as race 1 or race 2 based on the responses of differential cultivars of tomato and lettuce, or as defoliating or nondefoliating based on symptom expression in cotton. To investigate the frequency and distribution of races and defoliation phenotypes of cotton-associated V. dahliae, 317 isolates from China, Israel, Turkey, and the United States were tested by polymerase chain reaction (PCR) using defoliating, nondefoliating, and race 1- and race 2-specific primers DF/DR, NDF/NDR, VdAve1F/VdAve1R, and VdR2F/VdR2R, respectively. Of the total, 97.2% of isolates genotyped as defoliating were also characterized as race 2, while 90.8% of isolates genotyped as nondefoliating were also genotyped as race 1. To verify these results, three cotton cultivars—‘FM 2484B2F’ (highly resistant), ‘98M-2983’ (highly susceptible), and ‘CA4002’ (partially resistant)—used as differentials were each inoculated with 10 isolates characterized by PCR: six defoliating/race 2 strains (GH1005, GH1021, HN, XJ2008, XJ592, and reference strain Ls17) and four nondefoliating/race 1 strains (GH1015, GH1016, GH1020, and reference strain Ls16). All defoliating/race 2 isolates except for Ls17 caused defoliation on 98M-2983 and CA4002. Isolate Ls17 caused defoliation on 98M-2983 only. The nondefoliating/race 1 isolates caused Verticillium wilt symptoms devoid of defoliation on 98M-2983. The greenhouse assays confirmed the molecular identification of race and defoliation phenotype. Although the existence of races has not been previously established among V. dahliae isolates from cotton, the long-established nondefoliating and defoliating population structure corresponded with V. dahliae races 1 and 2, respectively.

scholarly journals Introgression of Big Vein Tolerance from Lactuca virosa L. into Cultivated Lettuce (Lactuca sativa L.)

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 881C-881 ◽  
Author(s):  
Ryan J. Hayes* ◽  
Ed Ryder ◽  
Bert Robinson
Keyword(s):  
Great Lakes ◽  
Lactuca Sativa ◽  
Infested Soil ◽  
Hybrid Progeny ◽  
Developmental Processes ◽  
Resistant Cultivars ◽  
Lactuca Virosa ◽  
Lactuca Sativa L ◽  
Congruity Backcrossing ◽  
Linkage Of Genes

Big vein (BV) disease of lettuce is caused by soil borne fungal vectored viruses, and reduces marketability through head deformation. Tolerant cultivars reduce BV frequency, but no resistant cultivars exist. L. virosa L. is highly resistance. The objectives were to 1) determine if L. virosa P.I.s exhibit variation for resistance, and 2) determine if resistance is transferable to lettuce. Seedlings were inoculated with root macerate of BV infected plants, transplanted to BV infested soil, and greenhouse grown for 3 months. Twelve plants in each of 1,2, or 3 reps of Great Lakes 65 (GL65-susceptible), Pavane (Pav-tolerant), L. virosa (11 accessions), and BC1 F2 through F5 families of lettuce cultivars x L. virosa accession IVT280 were tested. The percentage of BV afflicted plants was recorded. In hybrid families, BV free plants from tolerant families were selected and advanced. No BV was found in L. virosa. Variation for tolerance was observed in BC1 F2 and F3 families; 33% had greater tolerance than Pav (17% afflicted). Additional tests identified 11 BC1 F3 families (14%) with greater tolerance than Pav (42% afflicted). Subsequent BC1 F4 and F5 generations however, were more susceptible than Pav. Lactuca virosa is highly resistant, but resistance did not transfer to hybrid progeny. Variation for tolerance was observed in BC1 F2 and F3 families, but later generations were susceptible. Interactions or linkage of genes for developmental processes and BV resistance may hinder introgression. Introgression will continue using congruity backcrossing and a greater diversity of L. virosa.

Identification of two QTLs for resistance to Fusarium wilt race 1 in lettuce (Lactuca sativa L.)

Euphytica ◽  
2020 ◽  
Vol 216 (11) ◽  
Author(s):  
Kousuke Seki ◽  
Kenji Komatsu ◽  
Masahiro Hiraga ◽  
Keisuke Tanaka ◽  
Yuichi Uno ◽  
...  
Keyword(s):  
Fusarium Wilt ◽  
Lactuca Sativa ◽  
Lactuca Sativa L ◽  
Race 1

scholarly journals Delayed Foliar Symptoms Caused by Verticillium dahliae as an Alternative Resistance Trait in Iceberg Lettuce

HortScience ◽  
2017 ◽  
Vol 52 (4) ◽  
pp. 513-519
Author(s):  
Germán V. Sandoya ◽  
Krishna Subbarao ◽  
Ryan Hayes
Keyword(s):  
Verticillium Dahliae ◽  
Field Experiments ◽  
Economic Losses ◽  
Central Coast ◽  
Delayed Onset ◽  
Iceberg Lettuce ◽  
Foliar Symptoms ◽  
Race 1 ◽  
Resistance Trait ◽  
Race 2

Verticillium wilt caused by Verticillium dahliae Kleb. is an economically damaging disease of iceberg lettuce on the Central Coast of California. Foliar wilting symptoms that manifest near or at peak market maturity (MM) lead to collapse of the head, making it unmarketable. Complete resistance to race 1 of the pathogen is known, but adequate levels of resistance are not available against race 2. Additional mechanisms or traits that reduce foliar symptoms (FS) are needed to lessen economic losses from this disease. Since the disease affects leaves, the harvested product, identification of iceberg cultivars that delay the onset of FS past peak MM could reduce yield loss from the disease. The goal of this research was to identify iceberg lettuce germplasm with delayed onset of FS. Diverse iceberg cultivars were evaluated in replicated field experiments for MM, FS severity, and adaptation. A few winter-adapted cultivars showed fewer FS past MM and seem to be promising candidates for breeding. These cultivars are not adapted to the California Central Coast where the disease currently predominates. Further studies will determine the usefulness of this trait for breeding improved cultivars for use in V. dahliae–infested fields. Developing new cultivars that combine currently available sources of partial resistance against race 2 with delayed onset of FS could lead to reduced crop losses should race 2 of V. dahliae become widespread.

scholarly journals A Soilless Verticillium Wilt Assay Using an Early Flowering Lettuce Line

Plant Disease ◽  
2009 ◽  
Vol 93 (7) ◽  
pp. 691-698 ◽  
Author(s):  
Steven J. Klosterman ◽  
Ryan J. Hayes
Keyword(s):  
Verticillium Wilt ◽  
Rapid Assessment ◽  
Plant Introduction ◽  
Early Flowering ◽  
Flowering Plant ◽  
Growth Chamber ◽  
Race 1 ◽  
Race 2 ◽  
Greenhouse Assay ◽  
Time Required

A soilless growth chamber assay was evaluated for rapid assessment of Verticillium wilt on lettuce (Lactuca sativa). Seedlings of the early flowering Plant Introduction (PI) 251246 were inoculated in tubes with conidial suspensions of isolates of Verticillium dahliae from lettuce or cauliflower. PI 251246 developed significant leaf and root symptoms by 21 days following inoculation with isolates of race 1 and race 2 from lettuce, but not following inoculation with an isolate from cauliflower. In contrast, leaf symptoms on the cultivar La Brillante and root symptoms on the cultivar Salinas were not easily differentiated from the symptoms observed on the noninoculated control treatments in the soilless assay, even at the highest inoculum concentration of 1 × 107 conidia/ml. Comparison of the soilless growth chamber assay and a soil-based greenhouse assay revealed a significantly higher proportion of PI 251246 with root vascular discoloration in the soilless assay compared with the soil-based greenhouse assay (χ2, 1 df = 8.9; P = 0.003). There is thus an advantage to using the soilless growth chamber assay with PI 251246. Compared with the soil-based greenhouse assay, the soilless assay reduced the time required for evaluation of Verticillium wilt symptoms on lettuce from about 90 days to 42 days.

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