Screening of Wild and Cultivated Capsicum Germplasm Reveals New Sources of Verticillium Wilt Resistance

Verticillium wilt caused by Verticillium dahliae is an important soilborne disease of pepper (Capsicum species) worldwide. Most commercial pepper cultivars lack resistance to this pathogen. Our objective was to identify resistance to two V. dahliae isolates in wild and cultivated Capsicum accessions from the core collection of the National Plant Germplasm System of the USDA. Screening of 397 Capsicum accessions against two V. dahliae isolates (Vdca59 and VdCf45) was performed in a greenhouse. Seventy-eight accessions selected from this screen were further evaluated in a follow-up experiment. In total, 21 (26.9%) and 13 (16.6%) Capsicum accessions tested were resistant to Verticillium wilt when inoculated with V. dahliae isolates VdCa59 and VdCf45, respectively. Eight accessions (Grif 9073, PI 281396, PI 281397, PI 438666, PI 439292, PI 439297, PI 555616, and PI 594125) were resistant to Verticillium wilt against both V. dahliae isolates. On the basis of Germplasm Resources Information Network data, two of the Capsicum annuum accessions (Grif 9073 and PI 439297) were also resistant to Phytophthora root rot disease. These sources of multiple disease resistance will be useful to pepper breeding programs.

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The proportion of individual lucerne plants resistant to Phytophthora medicaginis and Colletotrichum trifolii in Australian cultivars

Australian Journal of Experimental Agriculture ◽

10.1071/ea97089 ◽

1998 ◽

Vol 38 (1) ◽

pp. 41 ◽

Cited By ~ 4

Author(s):

J. M. Mackie ◽

J. A. G. Irwin

Keyword(s):

Root Rot ◽

Crown Rot ◽

Sources Of Resistance ◽

Breeding Programs ◽

Phytophthora Root Rot ◽

Colletotrichum Trifolii ◽

Eastern Australia

Summary. Phytophthora root rot (Phytophthora medicaginis) and colletotrichum crown rot (Colletotrichum trifolii) are the 2 most serious pathogens of lucerne in eastern Australia. Work reported in this paper shows that in glasshouse tests of the 11 most commonly grown Australian lucerne cultivars, the proportion of individual plants with resistance to both pathogens ranges from 0 (Hunter River and Aurora) through to a maximum of 19.8% (Sequel HR). Within 9 of the cultivars, the proportion of individual plants resistant to the 2 pathogens was <7%. Since these 2 diseases are known to cause serious losses in eastern Australia, the results indicate further improvement in lucerne production can be obtained by increasing the proportion of individual plants in a cultivar resistant to both pathogens. This would be best achieved by identifying dominant sources of resistance and incorporating this into on-going lucerne breeding programs.

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Assessment of the control of Phytophthora root rot disease spread by Spin Out®-treated fabrics in container-grown hardy nursery-stock

Crop Protection ◽

10.1016/j.cropro.2007.05.007 ◽

2008 ◽

Vol 27 (2) ◽

pp. 198-207 ◽

Cited By ~ 1

Author(s):

T.R. Pettitt ◽

J.M. Monaghan ◽

M.A. Crawford

Keyword(s):

Root Rot ◽

Disease Spread ◽

Phytophthora Root Rot ◽

Root Rot Disease ◽

Nursery Stock ◽

Rot Disease

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Biological Control of Fungal Strawberry Diseases by Serratia plymuthica HRO-C48

Plant Disease ◽

10.1094/pdis.2001.85.5.529 ◽

2001 ◽

Vol 85 (5) ◽

pp. 529-534 ◽

Cited By ~ 73

Author(s):

Stefan Kurze ◽

Hubert Bahl ◽

Robert Dahl ◽

Gabriele Berg

Keyword(s):

Biological Control ◽

Plant Growth ◽

Verticillium Wilt ◽

Root Rot ◽

Fungal Pathogens ◽

Growth Promotion ◽

Field Trials ◽

Serratia Plymuthica ◽

Phytophthora Root Rot ◽

Bacterial Treatment

To develop a biological control product for commercial strawberry production, the chitinolytic rhizobacterium Serratia plymuthica strain HRO-C48 was evaluated for plant growth promotion of strawberries and biological control of the fungal pathogens Verticillium dahliae and Phytophthora cactorum. In phytochamber experiments, treatment with S. plymuthica HRO-C48 resulted in a statistically significant enhancement of plant growth dependent on the concentration of the bacterium that was applied. In greenhouse trials, bacterial treatment reduced the percentage of Verticillium wilt (18.5%) and Phytophthora root rot (33.4%). In three consecutive vegetation periods, field trials were carried out in soil naturally infested by both soilborne pathogens on commercial strawberry farms located in various regions of Germany. Dipping plants in a suspension of S. plymuthica prior to planting reduced Verticillium wilt compared with the nontreated control by 0 to 37.7%, with an average of 24.2%, whereas the increase of yield ranged from 156 to 394%, with an average of 296%. Bacterial treatment reduced Phy-tophthora root rot by 1.3 to 17.9%, with an average of 9.6%, and increased strawberry yield by 60% compared with the nontreated control. Under field conditions, strain HRO-C48 survived at approximately log10 3 to 7 CFU/g of root in the strawberry rhizosphere at 14 months after root application. Although results of the field trials were influenced by pathogen inoculum density, cropping history of the field site, and weather conditions, S. plymuthica HRO-C48 successfully controlled wilt and root rot of strawberry.

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Field resistance of crosses of sesame (Sesamum indicum L.) to charcoal root rot caused by Macrophomina phaseolina (Tassi.) Goid.

Plant Protection Science ◽

10.17221/2773-pps ◽

2010 ◽

Vol 42 (No. 2) ◽

pp. 66-72 ◽

Cited By ~ 1

Author(s):

M.A.S. El-Bramawy ◽

O.A. Abdul Wahid

Keyword(s):

Root Rot ◽

Natural Infection ◽

Correlation Coefficients ◽

Macrophomina Phaseolina ◽

Field Resistance ◽

Yield Potential ◽

Breeding Programs ◽

Rot Disease ◽

Positive Correlations ◽

Seed Yields

Two segregating generations (F3 and F4) from 6 × 6 half-diallel crosses, excluding reciprocals, of a sesame breeding program were exposed to natural infection by the root rot pathogen (Macrophomina phaseolina) in two successive seasons (2004 and 2005). There was highly significant variability in the progeny of all investigated crosses which might be a valuable tool for further breeding programs for root rot disease management. The level of infection in 2004 ranged from 2.63% (cross P2 × P5) to 52.42% (P4 × P5) in the F3, and from 1.28% (P1 × P5) to 51.78% (P4 × P5) in the F4. During 2005, infection varied from 1.01% (P2 × P5) to 50.91% (P4 × P5) in the F3, and from 1.00% (P3 × P4) to 48.00% (P4 × P5) in the F4. These crosses were ranked resistant or highly susceptible and gave seed yields per feddan (= 4200 m) of 536.67, 361.67, 641.67, and 408.33, respectively. The F3’s and F4’s of five crosses, i.e. P1 × P2, P1 × P4, P1 × P5, P2 × P6, and P3 × P4, were resistant in both segregating generations and both seasons. Such crosses might be helpful for breeding programs due to their stable resistance. Lines from the crosses P1 × P6, P2 × P4 and P4 × P5 could also be used for improving resistance due to an increase of inherited resistance from one generation to another. The estimated heritability showed high values in all cases and indicated that selection for these traits could be useful for breeding programs for resistance to root rot with seed yield potential. Correlation coefficients showed that there were some positive correlations such as percentage of infection by M. phaseolina between both generations (F3’s and F4’s) as well as within each generation during a season’s evaluation, i.e. 0.742, 0.976, 0.846, 0.732, and 0.987. The highest significant and positive correlations assisted in the selection of some crosses to be used in breeding programs and will aid breeders to achieve sesame cultivars with charcoal root rot resistance.

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Chile Pepper and The Threat of Wilt Diseases

Plant Health Progress ◽

10.1094/php-2003-0430-01-rv ◽

2003 ◽

Vol 4 (1) ◽

pp. 23 ◽

Cited By ~ 9

Author(s):

Soum Sanogo

Keyword(s):

Fusarium Wilt ◽

Verticillium Wilt ◽

Root Rot ◽

Plant Diseases ◽

Chile Pepper ◽

Phytophthora Root Rot ◽

Rhizoctonia Root Rot ◽

Chile Peppers

The popularity of chile peppers is providing a boost to the chile industry, but production is increasingly constrained by chile plant diseases. This article briefly describes four diseases that lead to wilting in chile: Phytophthora root rot, Verticillium wilt, Rhizoctonia root rot, and Fusarium wilt. Accepted for publication 18 April 2003. Published 30 April 2003.

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