The inheritance of resistance to Verticillium wilt caused by race 1 isolates of Verticillium dahliae in the lettuce cultivar La Brillante

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.

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First Report of Verticillium Wilt Caused by Verticillium dahliae on Mango Trees (Mangifera indica) in Southern Spain

Plant Disease ◽

10.1094/pdis-94-3-0380c ◽

2010 ◽

Vol 94 (3) ◽

pp. 380-380 ◽

Cited By ~ 3

Author(s):

L. Baeza-Montañez ◽

R. Gómez-Cabrera ◽

M. D. García-Pedrajas

Keyword(s):

Verticillium Wilt ◽

Verticillium Dahliae ◽

Mangifera Indica ◽

Southern Spain ◽

Reference Sequence ◽

Universal Primers ◽

First Report ◽

Wide Range ◽

Race 1 ◽

Disease Rating

Verticillium wilt, primarily caused by Verticillium dahliae Klebahn and V. albo-atrum Reinke & Berthold, affects a wide range of economically important crops. This disease is an increasing problem in areas where young mango trees are planted on land previously planted in vegetable crops. In 2008, symptoms of Verticillium wilt were observed in mango cvs. Kent and Osteen in the subtropical fruit-producing area of Málaga in southern Spain. In a new mango grove of cv. Kent, previously planted in potatoes and tomatoes, ~20% of 200 1-year-old trees had one-sided branch dieback. In many of these trees the symptoms expanded, leading to decline and eventual death. Cross sections of affected branches revealed brown vascular discoloration. Verticillium was isolated from surface-sterilized segments of symptomatic branches placed on acidic potato dextrose agar (PDA). Plates were incubated at 24°C. After 3 days, slow-growing colonies were transferred to PDA. Verticillium was similarly isolated from symptomatic potato plants grown in a nearby field. Identification of V. dahliae was initially based on morphology and further confirmed by molecular methods. All isolates tested produced microsclerotia, a defining feature that distinguishes V. dahliae from V. albo-atrum. For molecular characterization, V. dahliae specific primers 19 and 22 (1) and universal primers ITS1 and ITS4, which amplify the rRNA internal transcribed spacer (ITS) region (4), were used. Bands of expected size were amplified with both primer combinations. ITS fragments were sequenced and identical to the V. dahliae reference sequence (GenBank AY555948) (3). Pathogenicity assays were conducted with a selected isolate from mango using tomato plants from the susceptible line ‘Moneymaker’ and the near isogenic ‘Motabo’ line carrying the Ve gene conferring resistance to race 1 isolates. Five 1-month-old plants (four-leaf stage) were inoculated by root immersion in a suspension of 107 conidia/ml. Five control plants were mock inoculated with distilled water. As a positive control, five plants were inoculated with the previously described race 1 strain Dvd-T5 (2), which induces severe symptoms in susceptible tomato cultivars. Symptoms were scored visually at various time points up to 40 days by a 0 to 5 scale in which 0 = negligible chlorosis or wilting, 1 = chlorosis and wilting and/or curling in individual leaves, 2 = necrosis in leaves, 3 = at least one branch dead, 4 = wilt and/or chlorosis in upper leaves and/or two or more branches dead, and 5 = plant dead or all leaves and most of stem necrotic. The isolate from mango caused typical Verticillium wilt symptoms with a mean disease rating of 3.6 at 40 days postinoculation in both lines. The mean disease rating for Dvd-T5 in Moneymaker 40 days postinoculation was 4.0. V. dahliae was reisolated from symptomatic plants but not from noninoculated controls. To our knowledge, this is the first report of Verticillium wilt on mango in Spain. More problems with Verticillium wilt are expected because of the increasing planting of mango in fields previously dedicated to horticultural crops. References: (1) J. H. Carder et al. Modern Assays for Plant Pathogenic Fungi: Identification, Detection and Quantification. CAB International, Oxford, 1994. (2) K. F. Dobinson et al. Can. J. Plant. Pathol. 18:55, 1996. (3) M. P. Pantou et al. Mycol. Res. 109:889, 2005. (4) T. J. White et al. PCR Protocols: A Guide to Methods and Amplification. Academic Press, San Diego, 1990.

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Iceberg Lettuce Breeding Lines with Resistance to Verticillium Wilt Caused by Race 1 Isolates of Verticillium dahliae

HortScience ◽

10.21273/hortsci.46.3.501 ◽

2011 ◽

Vol 46 (3) ◽

pp. 501-504 ◽

Cited By ~ 9

Author(s):

Ryan J. Hayes ◽

Karunakaran Maruthachalam ◽

Gary E. Vallad ◽

Steven J. Klosterman ◽

Ivan Simko ◽

...

Keyword(s):

Verticillium Wilt ◽

Verticillium Dahliae ◽

Breeding Lines ◽

Iceberg Lettuce ◽

Lettuce Breeding ◽

Race 1

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Selection for Resistance to Verticillium Wilt Caused by Race 2 Isolates of Verticillium dahliae in Accessions of Lettuce (Lactuca sativa L.)

HortScience ◽

10.21273/hortsci.46.2.201 ◽

2011 ◽

Vol 46 (2) ◽

pp. 201-206 ◽

Cited By ~ 12

Author(s):

Ryan J. Hayes ◽

Karunakaran Maruthachalam ◽

Gary E. Vallad ◽

Steven J. Klosterman ◽

Krishna V. Subbarao

Keyword(s):

Genetic Variation ◽

Verticillium Wilt ◽

Verticillium Dahliae ◽

Partial Resistance ◽

Disease Incidence ◽

Greenhouse Experiments ◽

Complete Resistance ◽

Race 1 ◽

Selection For ◽

Race 2

Verticillium wilt of lettuce caused by Verticillium dahliae can cause severe economic damage to lettuce producers. The pathogen exists as two races (Races 1 and 2) in lettuce, and complete resistance to Race 1 is known. Resistance to Race 2 isolates has not been reported, and production of Race 1-resistant cultivars will likely increase the frequency of Race 2 strains. The objective of this research was to select lettuce accessions for resistance to Race 2 isolates of V. dahliae. Two independent populations totaling 314 randomly sampled PIs were evaluated for Verticillium wilt disease incidence (DI) caused by V. dahliae isolate VdLs17 in one unreplicated and two replicated greenhouse experiments. Selection for PIs with reduced DI was conducted between each experiment and plant stems were plated on semiselective media to identify colonized plants that remained non-symptomatic. No accession with complete resistance was identified, although accessions with partial resistance were selected. Genetic variation for the frequency of V. dahliae-colonized plants that remain symptomless was detected. Four PIs (169511, 171674, 204707, and 226641) were selected for further testing in three replicated greenhouse experiments and demonstrated significantly lower disease incidence than the susceptible control cultivars. The results indicate that lettuce has genetic variation for partial resistance to a Race 2 isolate of V. dahliae. The resistant PIs selected in this research are morphologically diverse, and no dependence between rate of bolting and resistance was found. PIs with partial resistance may be useful for breeding lettuce cultivars with resistance to Race 2 isolates of V. dahliae.

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Inheritance of resistance to Verticillium wilt (Verticillium dahliae) in cotton (Gossypium hirsutum L.)

Plant Breeding ◽

10.1111/j.1439-0523.2004.01040.x ◽

2005 ◽

Vol 124 (1) ◽

pp. 102-104 ◽

Cited By ~ 22

Author(s):

M. Mert ◽

S. Kurt ◽

O. Gencer ◽

Y. Akiscan ◽

K. Boyaci ◽

...

Keyword(s):

Gossypium Hirsutum ◽

Verticillium Wilt ◽

Verticillium Dahliae ◽

Inheritance Of Resistance ◽

Gossypium Hirsutum L

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GhKWL1 Upregulates GhERF105 but Its Function Is Impaired by Binding with VdISC1, a Pathogenic Effector of Verticillium dahliae

International Journal of Molecular Sciences ◽

10.3390/ijms22147328 ◽

2021 ◽

Vol 22 (14) ◽

pp. 7328

Author(s):

Yang Chen ◽

Mi Zhang ◽

Lei Wang ◽

Xiaohan Yu ◽

Xianbi Li ◽

...

Keyword(s):

Gene Expression ◽

Transgenic Plants ◽

Gossypium Hirsutum ◽

Verticillium Wilt ◽

Verticillium Dahliae ◽

Defense Response ◽

Upland Cotton ◽

Effector Protein ◽

Positive Regulator ◽

Its Gene

Verticillium wilt, caused by Verticillium dahliae, is a devastating disease for many important crops, including cotton. Kiwellins (KWLs), a group of cysteine-rich proteins synthesized in many plants, have been shown to be involved in response to various phytopathogens. To evaluate genes for their function in resistance to Verticillium wilt, we investigated KWL homologs in cotton. Thirty-five KWL genes (GhKWLs) were identified from the genome of upland cotton (Gossypium hirsutum). Among them, GhKWL1 was shown to be localized in nucleus and cytosol, and its gene expression is induced by the infection of V. dahliae. We revealed that GhKWL1 was a positive regulator of GhERF105. Silencing of GhKWL1 resulted in a decrease, whereas overexpression led to an increase in resistance of transgenic plants to Verticillium wilt. Interestingly, through binding to GhKWL1, the pathogenic effector protein VdISC1 produced by V. dahliae could impair the defense response mediated by GhKWL1. Therefore, our study suggests there is a GhKWL1-mediated defense response in cotton, which can be hijacked by V. dahliae through the interaction of VdISC1 with GhKWL1.

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