Sclerotinia Blight Resistance in Virginia-Type Peanut Transformed with a Barley Oxalate Oxidase Gene

Transgenic peanut lines expressing oxalate oxidase, a novel enzyme to peanut, were evaluated for resistance to Sclerotinia blight in naturally infested fields over a 5-year period. Area under the disease progress curve (AUDPC) for transgenic lines in single rows planted with seed from single-plant selections averaged 78, 83, and 90% lower than nontransgenic parents in 2004, 2005, and 2006, respectively. In addition, AUDPC in 14 transgenic lines planted with bulked seed in two-row plots averaged 81% lower compared with nontransgenic parents in 2005 and 86% lower in 16 transgenic lines in 2006. Six transgenic lines yielded 488 to 1,260 kg/ha greater than nontransgenic parents in 2005, and 10 lines yielded 537 to 2,490 kg/ha greater in 2006. Fluazinam (0.58 kg a.i./ha) fungicide sprays in 2008 and 2009 reduced AUDPC in transgenic and nontransgenic lines but AUDPC was lowest in transgenic lines. Without fluazinam, yields of transgenic lines averaged 1,133 to 1,578 kg/ha greater than nontransgenic lines in 2008 and 1,670 to 2,755 kg/ha greater in 2009. These results demonstrated that the insertion of barley oxalate oxidase in peanut conveyed a high level of resistance to Sclerotinia blight, and negated the need for costly fungicide sprays.

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Greenhouse Testing of Transgenic Peanut for Resistance to Sclerotinia minor

Peanut Science ◽

10.3146/pnut.30.2.0011 ◽

2003 ◽

Vol 30 (2) ◽

pp. 116-120 ◽

Cited By ~ 7

Author(s):

K. D. Chenault ◽

M. E. Payton ◽

H. A. Melouk

Keyword(s):

Fungal Pathogens ◽

Production Costs ◽

Lesion Length ◽

Susceptible Cultivar ◽

Sclerotinia Minor ◽

Sclerotinia Blight ◽

Mycelial Plug ◽

Transgenic Lines ◽

Fungal Genes ◽

Transgenic Peanut

Abstract Fungal diseases of peanut, such as Sclerotinia blight caused by Sclerotinia minor Jagger, are responsible for increased production costs and yield losses of up to 50% for peanut producers in the Southwest, North Carolina, and Virginia. A few cultivars with moderate disease resistance, such as Southwest Runner, have been developed through traditional breeding practices. An urgent need exists for developing peanut cultivars that are resistant to the broad spectrum of fungal pathogens that pose a recurring threat to peanut health. Transgenic peanut plant lines containing anti-fungal genes have been produced from somatic embryos of the susceptible cultivar Okrun and tested under greenhouse conditions for resistance to S. minor by inoculation with a mycelial plug. Disease symptoms of lesion length and vascular collapse were recorded for 30 transgenic peanut lines, non-transgenic Okrun, and Southwest Runner. The reaction of the majority of transgenic peanut lines to S. minor infection was indistinguishable from that of the susceptible cultivar Okrun. However, three transgenic lines had a significant increase in resistance to S. minor as compared to Okrun, and one line demonstrated levels of resistance comparable to the moderately resistant cultivar Southwest Runner.

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Comparison of Three Transgenic Peanut Lines with Their Parents for Agronomic and Physiological Characteristics

Peanut Science ◽

10.3146/0095-3679-42.2.74 ◽

2015 ◽

Vol 42 (2) ◽

pp. 74-82 ◽

Cited By ~ 1

Author(s):

Maria Balota ◽

D.E. Partridge-Telenko ◽

P.M. Phipps ◽

E.A. Grabau

Keyword(s):

Oxalate Oxidase ◽

The Other ◽

Physiological Characteristics ◽

Yield Potential ◽

Arachis Hypogea ◽

Sclerotinia Blight ◽

Transgenic Lines ◽

Significant Yield ◽

Large Kernel ◽

Similar Yield

ABSTRACT Peanut (Arachis hypogea L.) is an important crop in the Virginia-Carolina (VC) region, but cool and wet falls may result in significant yield reductions due to Sclerotinia blight, caused by Sclerotinia minor (Jagger), a major disease in the region. Transgenic lines expressing a barley oxalate oxidase were previously shown to confer improved resistance to the disease. This research compared three blight resistant transgenic lines for oxalate oxidase, N70, P39, and W73 with their non-transgenic parents, NC 7, Perry, and Wilson, and high yielding check cultivars Bailey and CHAMPS. The objective was to ensure that the agronomic and physiological characteristics of the transformed lines were not negatively impacted by the transformation with oxalate oxidase before making recommendations for production. In 2009 and 2010, experimental plots were grown in two distinct fields for soil type and available water capacity for a total of four environments. The transgenic lines were statistically comparable with their parents, Bailey, and CHAMPS for maturity, pod yield, gross value, and pod brightness. P39 consistently showed less extra-large kernel (ELK) and jumbo pod content than Perry and the other genotypes. N70 and NC 7, on the other hand, had the highest ELK and jumbo pod content. Overall, the transgenic lines exhibited similar yield potential and returns with their parents, Bailey, and CHAMPS when grown in the VC region.

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Progress in Breeding Sclerotinia Blight-Resistant Runner-Type Peanut1

Peanut Science ◽

10.3146/i0095-3679-22-2-7 ◽

1995 ◽

Vol 22 (2) ◽

pp. 109-113 ◽

Cited By ~ 20

Author(s):

J. J. Goldman ◽

O. D. Smith ◽

C. E. Simpson ◽

H. A. Melouk

Keyword(s):

Field Performance ◽

Screening Tests ◽

Chi Square ◽

Field Screening ◽

Disease Reaction ◽

Disease Progress Curve ◽

Disease Progress ◽

Sclerotinia Blight ◽

Progress Curve ◽

Single Cross

Abstract Field screening tests were conducted in 1991, 1992, and 1993 to identify Sclerotinia blight-resistant runner-type peanuts. Selections were made from three populations, “backcross to runner,” “backcross to Tamspan 90,” and “single cross.” Runner parents were chosen for agronomic qualities and resistance to other pathogens. Resistant (Spanish) parents used were cultivar Tamspan 90 and TxAG-5 germplasm. Families within populations were planted as single row 3 × 0.9-m plots. Repeated plant-by-plant inspections (PBPI) were made for assessment of sequence of infection and subsequent calculation of an area under the disease progress curve (AUDPC). Most families in the backcross to Tamspan 90 population consistently had a disease reaction close to or lower than Tamspan 90 but also retained undesirable plant forms (i.e., upright). By 1993, the F2:5 backcross to runner population had the highest percentage of runner-type families (88%) and a mean disease reaction close to Tamspan 90. Whole plot evaluation of Sclerotinia blight severity was compared with PBPI for effectiveness on a segregating population containing a total of 298 F4:7 single cross and F2:5 backcross entries. The whole plot system used a scale of 0 = no visible plot infection to 5 ≥80% infection in the plot. Correlation between area under disease progress curve values of both methods was high (>.85). Remnant seed of selections screened for resistance in the greenhouse were planted in the field and evaluated for resistance. Chi-square test for independence indicated a significant (α = .012) relationship between greenhouse and field performance. Field screening and limited greenhouse screening appears to be an effective way to develop resistant runner-type peanut lines.

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Susceptibility of Strawberry Cultivars and Advanced Selections to Leaf Spot Caused by Mycosphaerella fragariae

HortScience ◽

10.21273/hortsci.30.3.592 ◽

1995 ◽

Vol 30 (3) ◽

pp. 592-595 ◽

Cited By ~ 17

Author(s):

Nathalie Delhomez ◽

Odile Carisse ◽

Michel Lareau ◽

Shahrokh Khanizadeh

Keyword(s):

Cluster Analysis ◽

Disease Severity ◽

Leaf Spot ◽

High Susceptibility ◽

Disease Progress Curve ◽

Progress Curve ◽

High Level ◽

Mycosphaerella Fragariae ◽

Very High ◽

Strawberry Cultivars

Seventeen strawberry (Fragaria ×ananassa Duchesne) cultivars and six selections were tested under greenhouse conditions for susceptibility to leaf spot induced by Mycosphaerella fragariae (Tul.) Lindau. The level of susceptibility was evaluated based on maximum disease severity and area under the disease progress curve (AUDPC). The 23 genotypes were ranked based on AUDPC and grouped according to their susceptibility. Cluster analysis for AUDPC gave four groups corresponding to low, moderate, high, and very high susceptibility to leaf spot. `Annapolis', `Chambly', `Glooscap', `Redcoat', and `Veestar' consistently showed a low level of susceptibility. The selections SJ89700-1 and SJ8518-11 and `Tribute' showed a very high level of susceptibility, and the remaining cultivars were grouped as either moderately or highly susceptible.

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Effect of Crop Pruning on Sclerotinia Blight of Peanut

Plant Disease ◽

10.1094/pdis.1997.81.9.990 ◽

1997 ◽

Vol 81 (9) ◽

pp. 990-995 ◽

Cited By ~ 13

Author(s):

J. E. Bailey ◽

P. D. Brune

Keyword(s):

Disease Incidence ◽

Canopy Structure ◽

Plant Canopy ◽

Sclerotinia Minor ◽

Fungicide Treatment ◽

Disease Progress Curve ◽

Disease Progress ◽

Sclerotinia Blight ◽

Progress Curve ◽

Field Plots

Sclerotinia blight of peanut, incited by Sclerotinia minor, causes serious losses when cool, moist conditions prevail in the plant canopy. The effects of altering canopy structure by pruning were investigated in this study. Disease incidence was used to calculate area under the disease progress curve (AUDPC) for field plots receiving various shoot-pruning treatments. In 1990, pruned plots and iprodione-sprayed plots did not differ in AUDPC, but pruned plots produced higher yields. Disease levels and yield of July top-pruned plants did not differ from those of August top-pruned plants. Pruning tops and sides in August reduced yields compared to pruning tops and sides in July, even though August pruning produced lower AUDPC. Without fungicide treatment, the 1991 pruned plots had less disease than nonpruned plots, although yields did not differ significantly. Pruned plots treated with fungicides for control of Sclerotinia blight had less disease than nonpruned plots treated with these fungicides, but there were no differences in yield. Pruning peanut canopies to alter microclimate or enhance fungicide penetration may reduce disease and increase yield when S. minor damage is yield limiting.

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Correlation Between Transcript Abundance of the RB Gene and the Level of the RB-Mediated Late Blight Resistance in Potato

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-22-4-0447 ◽

2009 ◽

Vol 22 (4) ◽

pp. 447-455 ◽

Cited By ~ 49

Author(s):

Lara C. Kramer ◽

Mallory J. Choudoir ◽

Susan M. Wielgus ◽

Pudota B. Bhaskar ◽

Jiming Jiang

Keyword(s):

Late Blight ◽

Late Blight Resistance ◽

Transcript Abundance ◽

Blight Resistance ◽

Solanum Bulbocastanum ◽

Pathogen Infection ◽

Wild Potato Species ◽

Transgenic Lines ◽

Rb Gene ◽

High Level

Numerous disease-resistance genes have been cloned and characterized in various plant species. Only a few of these reported genes were transcriptionally induced or had enhanced transcription upon pathogen infection. Here, we report that transcription of the RB gene, which was cloned from the wild potato species Solanum bulbocastanum and confers resistance to potato late blight, was significantly increased after inoculation with the late blight pathogen Phytophthora infestans. Different RB transgenic lines showed different levels of resistance, which were correlated with the amounts of RB transcript in the transgenic plants. Different transgenic lines also showed different patterns of RB transcription 1, 3, and 5 days after P. infestans inoculation. Interestingly, the RB gene showed a higher basal level of transcription and a more dramatic transcriptional increase upon inoculation in S. bulbocastanum than in all potato transgenic lines. Our results revealed a predictive correlation between transcript abundance of the RB gene and the level of the RB-mediated late blight resistance. High level of resistance was associated with a combination of rapid RB transcript induction immediately after pathogen infection followed by the steady production of RB transcript. Thus, the transcription level of the RB gene provides a valuable marker for selecting and deploying RB-containing potato lines for late blight control.

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Morpho-Physiological Testing of NaCl Sensitivity of Tobacco Plants Overexpressing Choline Oxidase Gene

Plants ◽

10.3390/plants10061102 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1102

Author(s):

Galina N. Raldugina ◽

Sergey V. Evsukov ◽

Liliya R. Bogoutdinova ◽

Alexander A. Gulevich ◽

Ekaterina N. Baranova

Keyword(s):

Choline Oxidase ◽

Culture Methods ◽

Gene Encoding ◽

Oxidase Gene ◽

Bacterial Enzyme ◽

Transgenic Lines ◽

High Regeneration ◽

Whole Plants ◽

Implicit Response

In this study the transgenic lines (TLs) of tobacco (Nicotianatabacum L.), which overexpress the heterologous gene encoding the bacterial enzyme choline oxidase were evaluated. The goal of our work is to study the effect of choline oxidase gene expression on the sensitivity of plant tissues to the action of NaCl. The regenerative capacity, rhizogenesis, the amount of photosynthetic pigments and osmotically active compounds (proline and glycine betaine) were assessed by in vitro cell culture methods using biochemical and morphological parameters. Transgenic lines with confirmed expression were characterized by high regeneration capacity from callus in the presence of 200 mmol NaCl, partial retention of viability at 400 mmol NaCl. These data correlated with the implicit response of regenerants and whole plants to the harmful effects of salinity. They turned out to be less sensitive to the presence of 200 mmol NaCl in the cultivation medium, in contrast to the WT plants.

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Management of Daylily Rust With Different Fungicides and Fungicide Combinations

Plant Health Progress ◽

10.1094/php-03-17-0021-rs ◽

2017 ◽

Vol 18 (3) ◽

pp. 162-165 ◽

Cited By ~ 1

Author(s):

Robert S. Emmitt ◽

James W. Buck

Keyword(s):

United States ◽

Disease Management ◽

Disease Severity ◽

Low Cost ◽

Single Application ◽

Southeast United States ◽

Disease Progress Curve ◽

Disease Progress ◽

Progress Curve ◽

Disease Pressure

Production nurseries and daylily hybridizers in the southeast United States rely on the use of fungicides to manage daylily rust, caused by the fungus Puccinia hemerocallidis. Foliar sprays of pyraclostrobin, flutolanil, tebuconazole, myclobutanil, chlorothalonil, mancozeb, pyraclostrobin + boscalid, flutolanil + tebuconazole, flutolanil + myclobutanil, flutolanil + chlorothalonil, and flutolanil + mancozeb applied on 14-day intervals, and a nontreated control, were evaluated under high disease pressure at three locations in Griffin, GA, in 2015. Tebuconazole or the tebuconazole + flutolanil treatment consistently had the lowest area under the disease progress curve (AUDPC) of the treatments. The addition of flutolanil to chlorothalonil or mancozeb did not improve rust control and no difference in disease severity was observed in any treatment containing contact fungicides on all assessment dates. Single application costs ranged from $10.21 to $95.96 with tebuconazole providing excellent disease management at a relatively low cost per application ($13.90).

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Effects of Application Method and Rate on Control of Sclerotinia Blight of Peanut with Iprodione and Fluazinam1

Peanut Science ◽

10.3146/i0095-3679-28-1-8 ◽

2001 ◽

Vol 28 (1) ◽

pp. 28-33 ◽

Cited By ~ 8

Author(s):

J. P. Damicone ◽

K. E. Jackson

Keyword(s):

Disease Control ◽

Disease Incidence ◽

Maximum Yield ◽

Wide Band ◽

Yield Response ◽

Application Method ◽

Sclerotinia Blight ◽

Progress Curve ◽

Application Methods ◽

Yield Responses

Abstract Two trials with iprodione and three trials with fluazinam were conducted to assess the effects of application method and rate on the control of Sclerotinia blight of peanut with fungicide. In order to concentrate the fungicides near the crown area where the disease causes the most damage, applications were made through a canopy opener with a single nozzle centered over the row to achieve a 30.5-cm-wide band (canopy opener), and through a single nozzle centered over the row to achieve a 46-cm-wide band (band). Broadcast applications were compared to these methods at rates of 0, 0.28, 0.56, and 1.12 kg/ha on the susceptible cultivar Okrun. Sclerotinia blight was severe, with > 70% disease incidence and < 2000 kg/ha yield for the untreated controls in each trial. Linear reductions in area under the disease progress curve (AUDPC), but not final disease incidence, with iprodione rate were significant (P < 0.05) for all methods of application. However, the rate of decrease did not differ among application methods. Linear increases in yield with rate of iprodione were greater for canopy opener compared to the band or broadcast applications. Only a 50% reduction in AUDPC and a maximum yield of < 2700 kg/ha was achieved with iprodione using the best method. At the maximum rate of 1.12 kg/ha, fluazinam provided > 75% disease control and > 4000 kg/ha yield for all application methods. Differences in disease control and yield among application methods only occurred at the 0.28 and 0.56 kg/ha rates of fluazinam. Reductions in AUDPC with fluazinam rate were quadratic for all application methods, but AUDPC values were less for the canopy opener and band methods at 0.28 and 0.56 kg/ha compared to the broadcast methods. The yield response to rate for broadcast applications of fluazinam was linear. However, predicted yield responses to fluazinam rate were quadratic for the band and canopy opener methods and approached the maximum response at 0.84 kg/ha. Targeting fungicide applications using the band and/or canopy opener methods was beneficial for fluazinam at reduced rates. Disease control with iprodione was not adequate regardless of application method.

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Screening of the Argentinean INTA peanut core collection with a molecular marker associated with resistance to Sclerotinia minor Jaggar

Peanut Science ◽

10.3146/ps19-15.1 ◽

2020 ◽

Vol 47 (1) ◽

pp. 9-16

Author(s):

K.D. Chamberlin ◽

J.J. Baldessari ◽

E.M.C. Mamani ◽

M.V. Moreno

Keyword(s):

Molecular Marker ◽

Core Collection ◽

Field Tests ◽

Field Testing ◽

Blight Resistance ◽

Phenotypic Traits ◽

Sources Of Resistance ◽

Sclerotinia Minor ◽

Sclerotinia Blight ◽

Potential Sources

ABSTRACT Cultivated peanut, the third most important oilseed in the world, is consistently threatened by various diseases and pests. Sclerotinia minor Jagger (S. minor), the causal agent of Sclerotinia blight, is a major threat to peanut production in many countries and can reduce yield by up to 50% in severely infested fields. Host plant resistance will provide the most effective solution to managing Sclerotinia blight, but limited sources of resistance to the disease are available for use in breeding programs. Peanut germplasm collections are available for exploration and identification of new sources of resistance, but traditionally the process is lengthy, requiring years of field testing before those potential sources can be identified. Molecular markers associated with phenotypic traits can speed up the screening of germplasm accessions. The objective of this study was to genotype the peanut core collection of the Instituto Nacional de Tecnología Agropecuaria (INTA) Manfredi, Argentina, with a molecular marker associated with Sclerotinia blight resistance. One hundred and fifty-four (154) accessions from the collection were available and genotyped using the Simple Sequence Repeat (SSR) marker. Accessions from each botanical variety type represented in the core collection were identified as new potential sources of resistance and targeted for further evaluation in field tests for Sclerotinia blight resistance.

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