Durability of Resistance in Tomato and Pepper to Xanthomonads Causing Bacterial Spot

Bacterial disease management is a challenge for modern agriculture due to rapid changes in pathogen populations. Genome sequences for hosts and pathogens provide detailed information that facilitates effector-based breeding strategies. Tomato genotypes have gene-for-gene resistance to the bacterial spot pathogen Xanthomonas perforans. The bacterial spot populations in Florida shifted from tomato race 3 to 4, such that the corresponding tomato resistance gene no longer recognizes the effector protein AvrXv3. Genome sequencing showed variation in effector profiles among race 4 strains collected in 2006 and 2012 and compared with a race 3 strain collected in 1991. We examined variation in putative targets of resistance among Florida strains of X. perforans collected from 1991 to 2006. Consistent with race change, avrXv3 was present in race 3 strains but nonfunctional in race 4 strains due to multiple independent mutations. Effectors xopJ4 and avrBs2 were unchanged in all strains. The effector avrBsT was absent in race 3 strains collected in the 1990s but present in race 3 strains collected in 2006 and nearly all race 4 strains. These changes in effector profiles suggest that xopJ4 and avrBsT are currently the best targets for resistance breeding against bacterial spot in tomato.

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Development of Bacterial Spot on Near-Isogenic Lines of Bell Pepper Carrying Gene Pyramids Composed of Defeated Major Resistance Genes

Phytopathology ◽

10.1094/phyto.1999.89.11.1066 ◽

1999 ◽

Vol 89 (11) ◽

pp. 1066-1072 ◽

Cited By ~ 18

Author(s):

C. S. Kousik ◽

D. F. Ritchie

Keyword(s):

Disease Severity ◽

Resistance Genes ◽

Field Studies ◽

Residual Effects ◽

Specific Gene ◽

Near Isogenic Lines ◽

Bacterial Spot ◽

Isogenic Lines ◽

Major Resistance Genes ◽

Race 4

Disease severity caused by races 1 through 6 of Xanthomonas campestris pv. vesicatoria on eight near-isogenic lines (isolines) of Early Calwonder (ECW) with three major resistance genes (Bs1, Bs2, and Bs3) in different combinations was evaluated in the greenhouse and field. Strains representing races 1, 3, 4, and 6 caused similar high levels of disease severity, followed by races 2 and 5 on susceptible ECW. Race 3 caused severe disease on all isolines lacking resistance gene Bs2. Race 4, which defeats Bs1 and Bs2, caused less disease on isoline ECW-12R (carries Bs1 + Bs2), than on isolines ECW, ECW-10R (carries Bs1), and ECW-20R (carries Bs2). Similar results were obtained with race 4 strains in field studies conducted during 1997 and 1998. In greenhouse studies, race 6, which defeats all three major genes, caused less disease on isoline ECW-13R (carries Bs1 + Bs3) and ECW-123R (carries Bs1 + Bs2 + Bs3) than on isolines ECW, ECW-10R, ECW-20R, and ECW-30R (carries Bs3), but not on ECW-23R (carries Bs2 + Bs3). In greenhouse studies with commercial hybrids, strains of races 4 and 6 caused less disease on Boynton Bell (carries Bs1 + Bs2) than on Camelot (carries no known resistance genes), King Arthur (carries Bs1), and X3R Camelot (carries Bs2). Race 6 caused less disease on hybrid R6015 (carries Bs1 + Bs2 + Bs3) and Sentinel (carries Bs1 + Bs3) than on Camelot. Residual effects were not as evident in field studies with race 6 strains. Defeated major resistance genes deployed in specific gene combinations (i.e., gene pyramids) were associated with less area under the disease progress curve than when genes were deployed individually in isolines of ECW or commercial hybrids. Successful management of bacterial spot of pepper is achieved incrementally by integrating multiple tactics. Although there is evidence of residual effects from defeated genes, these effects alone likely will not provide acceptable bacterial spot control in commercial production fields. However, when combined with sanitation practices and a judicious spray program, pyramids of defeated resistance genes may aid in reducing the risk of major losses due to bacterial spot.

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Effect of Compost Amendments on Disease Severity and Yield of Tomato in Conventional and Organic Production Systems

Plant Disease ◽

10.1094/pdis.2002.86.2.156 ◽

2002 ◽

Vol 86 (2) ◽

pp. 156-161 ◽

Cited By ~ 83

Author(s):

P. A. Abbasi ◽

J. Al-Dahmani ◽

F. Sahin ◽

H. A. J. Hoitink ◽

S. A. Miller

Keyword(s):

Disease Severity ◽

Production Systems ◽

Disease Incidence ◽

Organic Production ◽

Fruit Rot ◽

High Rate ◽

Bacterial Spot ◽

Marketable Yield ◽

Tomato Production ◽

Compost Amendments

Field trials were conducted over 2 years to assess the effects of compost amendments on disease development in organic and conventional processing tomato (Lycopersicon esculentum L.) production systems. The incidence of anthracnose fruit rot was reduced in organic tomato plots amended with a high rate of composted cannery wastes compared with the incidence in nonamended control plots in 1998 when disease incidence was high. Marketable yield was increased by 33% in compost-amended organic plots. Plots amended with a high compost rate had more ripe fruit than the nonamended control. The incidence of anthracnose and of total disease on fruit was less on the cultivar OH 8245 than on Peto 696. Total fruit yield of OH 8245 but not Peto 696 in organic plots was increased by amendment with composted cannery wastes. In conventional tomato production, composted yard wastes increased disease severity on foliage both years but reduced bacterial spot incidence on fruit in 1997, when disease pressure was high. The incidence of anthracnose was not affected by composted yard wastes. Marketable and total fruit yields of Peto 696 were not increased in compost-amended conventional plots. The plant activator Actigard reduced foliar disease severity and the incidence of bacterial spot and anthracnose on fruit, while increasing yield of marketable fruit.

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Resistance of Xanthomonas campestris pv. vesicatoria isolates from Tanzania to copper and implications for bacterial spot management

African Journal of Microbiology Research ◽

10.5897/ajmr2013.5836 ◽

2014 ◽

Vol 8 (30) ◽

pp. 2881-2885 ◽

Cited By ~ 4

Author(s):

C. Shenge Kenneth ◽

B. Mabagala Robert ◽

N. Mortensen Carmen ◽

Wydra Kerstin

Keyword(s):

Xanthomonas Campestris ◽

Bacterial Spot

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First Report of Bacterial Spot of Tomato Caused by Xanthomonas perforans in Mississippi

Plant Disease ◽

10.1094/pdis-04-18-0708-pdn ◽

2019 ◽

Vol 103 (1) ◽

pp. 147-147

Author(s):

P. Abrahamian ◽

J. M. Klein ◽

J. B. Jones ◽

G. E. Vallad ◽

R. A. Melanson

Keyword(s):

Bacterial Spot ◽

First Report ◽

Xanthomonas Perforans

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Bacterial spot of tomato: Biology and management

Crops & Soils ◽

10.2134/cs2015-48-3-9 ◽

2015 ◽

Vol 48 (3) ◽

pp. 32-34

Author(s):

Beth K. Gugino

Keyword(s):

Bacterial Spot

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Development of a Model to Predict the Primary Infection Date of Bacterial Spot (Xanthomonas campestris pv. vesicatoria) on Hot Pepper

The Plant Pathology Journal ◽

10.5423/ppj.oa.09.2013.0090 ◽

2014 ◽

Vol 30 (2) ◽

pp. 125-135 ◽

Cited By ~ 3

Author(s):

Ji-Hoon Kim ◽

Wee-Soo Kang ◽

Sung-Chul Yun

Keyword(s):

Primary Infection ◽

Xanthomonas Campestris ◽

Hot Pepper ◽

Bacterial Spot

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Protecting vegetable cultivars in Brazil: a chili pepper case-study research

Horticultura Brasileira ◽

10.1590/s0102-053620160000200003 ◽

2016 ◽

Vol 34 (2) ◽

pp. 161-167 ◽

Cited By ~ 1

Author(s):

Samy Pimenta ◽

Rosana Rodrigues ◽

Cláudia P Sudré ◽

João GT Moraes ◽

Cíntia S Bento ◽

...

Keyword(s):

Recombinant Inbred Lines ◽

Block Design ◽

Case Study Research ◽

Fruit Shape ◽

Bacterial Spot ◽

Randomized Block Design ◽

Dus Testing ◽

Bacterial Spot Resistance ◽

Test Requirements ◽

L1 And L2

ABSTRACT: In all countries, members of the UPOV (Union Internationale pour la Protection des Obtentions Végétales), of which Brazil is a signatory, to protect a new plant variety is necessary to carry out DUS (Distinctness, Uniformity and Stability) tests. DUS testing forCapsicum spp. is based on 48 descriptors, which involve qualitative and quantitative traits, observed from germination to fruit harvest. This paper describes the performance of DUS tests on lines of chili peppers, which are candidates for protection; we discuss the main aspects related to operational difficulties, the relevance of some descriptors for the protection process and highlight the importance of protecting new plant varieties as national intellectual property. Four C. annuum var.annuum recombinant inbred lines were tested. The Capsicum Breeding Program of the Universidade Estadual do Norte Fluminense Darcy Ribeiro developed the lines, which are resistant to bacterial spot. They were tested under greenhouse conditions from June to November 2013; and from January to July 2014 in Campos dos Goytacazes, Rio de Janeiro State, Brazil. The 'Jalapeño M' commercial genotype was used as control and treatments were arranged in a randomized block design with seven plants per plot with five replications. Besides the 48 descriptors, stipulated by legislation for Capsicum DUS testing, we included a descriptor for bacterial spot resistance. The descriptors that enabled distinction varied with each line. Although being distinctive for some descriptors, L1 and L2 lines were neither homogeneous nor stable. L6 and L8 recombined lines were characterized by homogeneity and stability. Fruit shape, capsaicin presence, number of days for flowering and bacterial spot resistance were descriptors that allowed for differentiation between treatments. In conclusion, the L6 and L8 recombined lines met the DUS test requirements; therefore, they may be subjected to the protection process with the Brazilian Ministry of Agriculture, Livestock and Food Supply.

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