Cercosporidium Personatum Research Articles

Yield performance and pest resistance among peanut genotypes when grown without fungicides or insecticides

Yield trials without fungicides or insecticides were conducted four consecutive years (2007–10) at the University of Georgia, Coastal Plain Experiment Station, Tifton Campus to evaluate for peanut (Arachis hypogaea L.) pest resistance. The most endemic diseases in the southeast U.S. are tomato spotted wilt (TSW) caused by Tomato spotted wilt virus, white mold (WM) caused by Sclerotium rolfsii Sacc, and both early and late leaf spot caused by Cercospora arachidicola Hori and Cercosporidium personatum (Berk & Curt.) Deighton, respectively. The most endemic insects are tobacco thrips (Frankliniella fusca Hinds) and potato leafhopper (Empoasca fabae Harris). Results from these replicated field tests showed significant differences (P ≤ 0.05) among advanced Georgia breeding lines and cultivars. Three Georgia cultivars ‘Georgia-01R’, ‘Georgia-05E’, and ‘Georgia-10T’ consistently produced among the best yields with high levels of resistance to TSW, white mold, leafhoppers, and leaf spot each year. Georgia-01R is a multiple-pest-resistant, runner-type cultivar with late maturity; whereas, Georgia-05E is a multiple-pest-resistant, virginia-type cultivar with medium-late maturity. Georgia-10T is a new runner-type cultivar with high level of TSWV and white mold resistance and late-maturity, similar to Georgia-01R, one of its parents. However, Georgia-10T does not appear to have the high level of leaf spot and leafhopper resistance as Georgia-01R, but it still had high yields in the absence of fungicides or insecticides.

Management of Late Leaf Spot of Groundnut by Different Fungicides and Their Impact on Yield

In vitro experiments were carried out with Phaeoisariopsis personata isolate to determine its sensitivity/tolerance to different fungicides viz., Tebuconazole (0.05%), Tebuconazole (0.10%), Tebuconazole (0.15%), Tebuconazole (0.20%), Tebuconazole (0.40%), Folicur (0.10%) and Mancozeb (0.30%) using poisoned food technique both in solid and liquid medium. In the solid medium method, visual observation was taken 20 days after inoculation of the pathogen. There was no significant difference among the different fungicides in their efficacy against P. personata, compared to control. In case of liquid medium the observations were taken after 25 days of inoculation and the results are presented. There was significant difference between the fungicides in per cent inhibition against the mycelial growth of the pathogen, P. personata. Among all the fungicides, Tebuconazole 0.4% (87.97%t) showed maximum inhibition followed by Tebuconazole 0.2% (85.24%) and Tebuconazole 0.15% (83.50%), among these Tebuconazole 0.15% was found to be optimum. Application of fungicidal sprays influenced the development of Cercospora leaf spot and reduced its intensity. Among these applications of different fungicides, Tebuconazole (0.15%) gave best result and reduced the disease intensity to 52.42%. Area under disease progress curve (AUDPC) greatly varied among different fungicidal treatments and showed significant difference in yield data. Impact of fungicides used for disease control was apparent on yield per plot. Tebuconazole (0.15%) gave best result and increased yield up to 67% as compared to 39% increase by Tebuconazole (0.10 %).

Genetic analysis of resistance to late leaf spot in interspecific groundnuts

Late leaf spot (LLS), caused by Phaeoisariopsis personata, is an important foliar fungal disease of groundnut (Arachis hypogaea L.), which causes significant economic losses globally to the crop. Inheritance of resistance to LLS disease was studied in three crosses and their reciprocals involving two resistant interspecific derivatives and a susceptible cultivar to refine strategy for LLS resistance breeding. The traits associated with LLS resistance, measured both in the field and under controlled conditions were studied following generation mean analysis. Results suggested that resistance to LLS is controlled by a combination of both, nuclear and maternal gene effects. Among nuclear gene effects, additive effect controlled majority of the variation. In JL 24 × ICG 11337 cross and its reciprocal only additive effects were important, while in JL 24 × ICG 13919 cross and its reciprocal, both additive and dominance effects contributed to the variation. Among digenic epistatic effects, additive × dominance interactions were significant. Additive–maternal effects were significant in both the crosses, while dominance–maternal effects also contributed to the variation in the crosses between the parents, JL 24 and ICG 13919. Due to significant contribution of additive effects of both nuclear and maternal inheritance to resistance to LLS, the parent, ICG 11337 would be a good donor in breeding programs. It would be worthwhile to use the resistance donor as female parent to tap maternal effects of resistance to LLS. Disease score is the best selection criterion in the field for use in breeding programs because of its high heritability and ease in measurement.

Evaluation of Peanut Agrochemical Efficacy in Situations where Spray Solution Application is Delayed

ABSTRACT The effect of delayed application of spray solutions is poorly understood with respect to efficacy of fungicides, insecticides, inoculants, and plant growth regulators commonly used in peanut (Arachis hypogaea L.). Research was conducted in North Carolina during 2009 and 2010 to determine if tobacco thrips (Frankliniella fusca Hinds) control by acephate; early leaf spot (caused by Cercospora arachidicola Hori) and late leaf spot (caused by Cercosporidium personatum Berk. and Curt.) control by chlorothalonil, prothioconazole plus tebuconazole, pyraclostrobin, and tebuconazole; Sclerotinia blight (caused by Sclerotinia minor Jagger) control by boscalid and fluazinam; and improvement in row visibility by prohexadione calcium were affected by the time interval between solution preparation and application. Performance of the inoculant Bradyrhizobium was also compared when prepared in 25 different sources of water when application was delayed after preparation of solutions. Agrochemicals and prohexadione calcium solutions were prepared the d of application or 3, 6, and 9 d prior to application with all solutions applied on the same d. Similarly, inoculant solutions were prepared the d of application or 4 and 8 d prior to application and applied on the same d. Performance of fungicides, insecticides, inoculant, and prohexadione calcium was not reduced in most instances when left in spray solution up to 8 or 9 d. The magnitude of difference in efficacy was minor when differences were observed.

Increased resistance to late leaf spot disease in transgenic peanut using a combination of PR genes

Peanut (Arachis hypogaea L.) is the sixth most important oil seed crop in the world. Yield loss due to Cercospora leaf spot (early and late leaf spots) is a serious problem in cultivating this crop. Non-availability of resistant genes within crossable germplasms of peanut necessitates the use of a genetic engineering strategy to develop genetic resistance against various biotic stresses. The pathogenesis-related (PR) proteins are a group of plant proteins that are toxic to invading fungal pathogens, but are present in trace amounts in plants. The PR proteins, PR-5 and defensins, are potent antifungal proteins. A double gene construct with SniOLP (Solanum nigrum osmotin-like protein) and Rs-AFP2 (Raphanus sativus antifungal protein-2) genes under separate constitutive 35S promoters was used to transform peanut plants. Transgenic peanut plants expressing the SniOLP and Rs-AFP2 genes showed enhanced disease resistance to late leaf spot based on a reduction in number and size of lesions on leaves and delay in the onset of Phaeoisariopsis personata leaf spot disease. PCR, RT-PCR, and Southern hybridization analyses confirmed stable integration and expression of these genes in peanut transgenics. The results demonstrate the potential of SniOLP and Rs-AFP2 genes in developing late leaf spot disease resistance in transgenic peanut.

Global transcriptome analysis of two wild relatives of peanut under drought and fungi infection

BackgroundCultivated peanut (Arachis hypogaea) is one of the most widely grown grain legumes in the world, being valued for its high protein and unsaturated oil contents. Worldwide, the major constraints to peanut production are drought and fungal diseases. Wild Arachis species, which are exclusively South American in origin, have high genetic diversity and have been selected during evolution in a range of environments and biotic stresses, constituting a rich source of allele diversity. Arachis stenosperma harbors resistances to a number of pests, including fungal diseases, whilst A. duranensis has shown improved tolerance to water limited stress. In this study, these species were used for the creation of an extensive databank of wild Arachis transcripts under stress which will constitute a rich source for gene discovery and molecular markers development.ResultsTranscriptome analysis of cDNA collections from A. stenosperma challenged with Cercosporidium personatum (Berk. and M.A. Curtis) Deighton, and A. duranensis submitted to gradual water limited stress was conducted using 454 GS FLX Titanium generating a total of 7.4 x 105 raw sequence reads covering 211 Mbp of both genomes. High quality reads were assembled to 7,723 contigs for A. stenosperma and 12,792 for A. duranensis and functional annotation indicated that 95% of the contigs in both species could be appointed to GO annotation categories. A number of transcription factors families and defense related genes were identified in both species. Additionally, the expression of five A. stenosperma Resistance Gene Analogs (RGAs) and four retrotransposon (FIDEL-related) sequences were analyzed by qRT-PCR. This data set was used to design a total of 2,325 EST-SSRs, of which a subset of 584 amplified in both species and 214 were shown to be polymorphic using ePCR.ConclusionsThis study comprises one of the largest unigene dataset for wild Arachis species and will help to elucidate genes involved in responses to biological processes such as fungal diseases and water limited stress. Moreover, it will also facilitate basic and applied research on the genetics of peanut through the development of new molecular markers and the study of adaptive variation across the genus.

SSR markers associated for late leaf spot disease resistance by bulked segregant analysis in groundnut (Arachis hypogaea L.)

Late leaf spot (LLS) caused by Phaeoisariopsis personata is the major foliar disease that reduces the pod yield and severely affects the fodder and seed quality in groundnut. Molecular markers linked with LLS can improve the process of identification of resistant genotypes. In the present study, a LLS susceptible genotype (TMV 2) and the LLS resistant genotype (COG 0437) were crossed and their F2 population was used for marker analysis. The phenotypic mean data on F2:3 progenies were used as phenotype. Parents were surveyed with 77 SSR (Simple Sequence Repeat) primers to identify polymorphic markers. Among SSR markers, nine primers were found polymorphic between the parents TMV 2 and COG 0437. These markers were utilized for bulked segregant analysis (BSA). Among the polymorphic SSR markers, three primers viz., PM 375162, pPGPseq5D5220 and PM 384100 were able to distinguish the resistant and susceptible bulks and individuals for LLS. In single marker analysis, the markers PM 375, PM 384, pPGPseq5D5, PM 137, PM 3, PMc 588 and Ah 4-26 were linked with LLS severity score. The phenotypic variation explained by these markers ranged from 32 to 59 %. The markers identified through BSA were also confirmed with single marker analysis. While validating the three primers over a set of resistant and susceptible genotypes, the primer PM 384100 allele had association with resistance. Hence PM 384 could be utilized in the marker assisted breeding programme over a wide range of genetic background.

Reduced fungicide use on a new Australian peanut cultivar, highly resistant to the late leaf spot and rust pathogens

Rust (caused by Puccinia arachidis) and late leaf spot (LLS, caused by Mycosphaerella berkeleyi) can cause significant yield losses in Australian peanut crops. Until recently, all commercial peanut varieties were highly susceptible to these pathogens, but the new Australian cultivar Sutherland has significantly higher levels of resistance than the older cultivars. Field trials were conducted at two sites in Queensland to (a) confirm the improved resistance of cv. Sutherland over another commercial cultivar, Menzies, (b) study the effects of timing of first spray, spray interval and cultivar on disease severity and yield, and (c) develop a suitable fungicide management program for cv. Sutherland. In the 2006 and 2007 trials, rust and LLS developed slower and had lower final disease ratings and AUDPC values on unsprayed plots of cv. Sutherland than on cv. Menzies. The timing of the first spray is critical in managing both rust and late leaf spot, with the results demonstrating that the first fungicide spray on cv. Sutherland should be applied as soon as rust and LLS are first seen on cv. Menzies. In most trials spray intervals of 14 days or 21 days were suitable to effectively control rust and LLS. In years with low disease pressure, few, if any, fungicide applications will be needed to manage the diseases, but in other years up to four sprays may be necessary.

Epidemiology of the Groundnut (<i>Arachis hypogaea</i> L.) Leaf Spot Disease: Genetic Analysis and Developmental Cycles

Groundnut leaf spot is one of the important factors limiting groundnut productivity in Africa particularly in the Democratic Republic of Congo (DR Congo). Early and late leaf spot disease of groundnut caused by Cercospora arachidicola Hori and Cercosporidium personatum (Berk & Curt.) Deighton, respectively, can cause considerable yield losses without fungicide management. The main objectives of this research were to analyze plant and disease developmental cycles. Significant differences were observed among the groundnut varieties evaluated for resistance to the leaf spot disease. The results show that plant development cycle can be divided into three developmental stages. A first stage characterized by a low production of leaves, a second stage with a significant leaf development and finally a third stage with a reduction of leaves. Interestingly, the leaf spot disease cycle was also divided in three stages. The disease stage characterized by the highest level of symptom expression was not associated with the plant phase with the highest emerged leaves. Disease symptoms reached the highest pick only after the phase of intense leaf development. The molecular analysis revealed that all the groundnut varieties analyzed were genetically closely related even though they showed different reactions to the leaf spot disease.

Photosynthetic Consequences of Late Leaf Spot Differ between Two Peanut Cultivars with Variable Levels of Resistance

ABSTRACTLate leaf spot (LLS) caused by Cercosporidium personatum (Berk. & Curt.) Deighton reduces leaf CO2 assimilation rate (Asat) and accelerates leaf defoliation, which together lead to major reductions in peanut (Arachis hypogaea L.) yield worldwide. This study was conducted to determine whether differences in photosynthetic response to LLS severity exist among peanut cultivars of differing resistance. Field experiments were conducted in 2008 and 2009 to study the effects of LLS on Asat of tagged leaf cohorts, and photosynthetic response of similar age leaves to LLS in peanut cultivars with more (York) and less (Carver) quantitative resistance. A nonlinear model, y = (1 − x)β was used to analyze Asat data, where y is relative Asat, x is measured visual lesion area, and β represents the relationship between virtual and visual lesion area. Progression of LLS severity on leaf cohorts was slower in York than in Carver. However, the reduction in Asat with leaf cohort age was similar across the cultivars. This paradox could be explained by a higher β value in York (4.6) than in Carver (3.6), indicating a greater relative reduction in Asat beyond the necrotic lesion area in York. This greater reduction in Asat in York compared to Carver was most closely related to a reduction in maximum carboxylation velocity. Results indicated that future efforts to improve LLS resistance should include sustaining Asat in response to LLS infection along with slower disease progress.

Resistência à mancha preta em populações F4 selecionadas de cruzamentos entre o amendoim cultivado e um anfidiplóide de Arachis

Neste trabalho avaliou-se, em condições de campo, o potencial de resistência à mancha preta (Cercosporidium personatum) em plantas F4, selecionadas de cruzamentos entre genótipos de Arachis hypogaea (acessos VGaRoSv 12549 e VGaRoSv 12548 e a cultivar IAC Caiapó) e um anfidiplóide sintético (Arachis ipäensis x Arachis duranensis)4x. O experimento foi desenvolvido no ano agrícola de 2007/2008, em Pindorama (SP). Avaliaram-se noventa e três famílias de plantas em F4, em parcelas com dez plantas distribuídas em linhas de três metros de comprimento, espaçadas de dois metros, bem como os controles, as cultivares IAC Caiapó e Runner IAC 886, a espécie A. ipäensis e o anfidiplóide. Foram realizadas três avaliações da doença durante o ciclo, utilizando uma escala diagramática de notas visuais de sintomas de lesões e desfolha. Avaliaram-se também alguns caracteres morfoagronômicos, como indicativos da proximidade do material silvestre com o cultivado. A variabilidade da resistência à doença foi estudada através das médias de ASCPD (Área sob a Curva de Progresso da Doença). Pelos resultados constata-se que o anfidiplóide utilizado é interessante fonte de resistência. A seleção pelo método genealógico propiciou obter indivíduos com resistência ao nível do parental silvestre, mas as chances de se obter indivíduos resistentes e com caracteres agronômicos desejáveis é pequena, sugerindo a necessidade de retrocruzamentos.

Screening new Arachis amphidiploids, and autotetraploids for resistance to late leaf spot by detached leaf technique

Cultivated groundnut is susceptible to late leaf spot (LLS) caused by Phaeoisariopsis personata [(Berk. & M.A. Curtis) Aex] and resistance is low to moderate in the primary gene pool of groundnut. Closely related wild species in the secondary gene pool are highly resistant to the disease. All the closely related Arachis species are diploid and cultivated groundnut is a tetraploid. Utilization of diploid Arachis species to transfer LLS resistance is time consuming and cumbersome. New sources of Arachis hypogaea (also called synthetic groundnut) were developed at ICRISAT. These are tetraploids and the present investigation has shown that they are resistant to LLS.

Registration of ‘York’ Peanut

‘York’ (Reg. No. CV‐114, PI 653717) peanut (Arachis hypogaea L. subsp. hypogaea var. hypogaea) cultivar was developed at the University of Florida, Florida Agricultural Experiment Station, North Florida Research and Education Center near Marianna, FL, and was approved for release in 2006. York was tested as UF04321 and has runner market‐type pods and seed with a prostrate runner growth habit. Under irrigated production in Florida, York matures in approximately 150 d, making it a late‐maturing cultivar. York has good‐to‐excellent multiple disease resistance, namely to late leaf spot [caused by Cercosporidium personatum (Berk. & M.A. Curtis) Deighton], Tomato spotted wilt virus, and white mold/stem rot (caused by Sclerotium rolfsii Sacc.). York has shown good‐to‐excellent pod yields and disease resistance in Florida tests. Seed of York have a high‐oleic oil chemistry (approximately 80% oleic fatty acid), which greatly enhances shelf life and quality characteristics. York should provide southeastern U.S. growers with a cultivar having excellent disease resistance and quality characteristics.

HarpinPss-mediated enhancement in growth and biological control of late leaf spot in groundnut by a chlorothalonil-tolerant Bacillus thuringiensis SFC24

Chemical and biological approaches have been adopted to increase the growth and yield of crops and reduce loss due to diseases. We have adopted an integrated approach, where both direct antagonism and induced resistance were combined to reduce the incidence of late leaf spot (LLS) disease in groundnut caused by Phaeoisariopsis personata. Chitinolytic chlorothalonil-tolerant soil bacterium Bacillus thuringiensis SFC24 (Bt SFC24) was manipulated in vitro to express secretable form of elicitor protein harpinPss of Pseudomonas syringae pv. syringae. Severity of the LLS decreased by 65% when the leaves were sprayed with B. thuringiensis expressing harpinPss (Bt-pss). As seed treatment, there was an increase in growth of groundnut. Bt and Bt-pss accounted to 13% and 36% increase in shoot length. Expression of a secretable form of harpinPss thus improved the ability of B. thuringiensis SFC24 to promote growth and control LLS in groundnut. In this new approach a chlorothalonil-tolerant chitinolytic bacterium was genetically engineered to secrete elicitor harpinPss for dual benefit of growth promotion and disease control.

EFFECT OF APPLICATION METHODS OF PSEUDOMONAS JBIOPEST 5(1): 1-6 FLUORESCENS FOR THE LATE LEAF SPOT OF GROUNDNUT MANAGEMENT

ABSTRACT Late leaf spot incited by Cercosporidium personatum is the serious disease in groundnut. The effect of different methods of application of Pseudomonas fluorescens (Pf1) in managing late leaf spot of groundnut was assessed under greenhouse condition. Among the different methods tested, seed treatment coupled with foliar application of Pf1 formulation was found to be the most effective in managing late leaf spot disease. The boosting effect of Pf1 formulation on plant growth was evidenced by the fact that the plant height, leaf area index, root length, nodules per plant and dry matter production were the maximum in P. fluorescens treated plants. Pod yield was also found to be increased by using Pf1. Seed treatment followed by foliar application of Pf1 formulation gave the maximum pod yield.

Response of progeny bred from Bolivian and North American cultivars in integrated management systems for leaf spot of peanut ( Arachis hypogaea)

Early and late leaf spot (caused by Cercospora arachidicola and Cercosporidium personatum, respectively) are major yield-reducing diseases of peanut ( Arachis hypogaea L.) in the southeastern U.S. Effective suppression of both early and late leaf spot, collectively called ‘leaf spot’, can be reached with integrated disease management (IDM) systems utilizing peanut cultivars with moderate levels of resistance to these pathogens. A Bolivian landrace cultivar, Bayo Grande, and a series of progeny breeding lines were evaluated under two IDM systems consisting of various reduced application fungicide regimes and/or tillage treatments in field experiments over two years. In the absence of fungicides or when averaged across fungicide regimes, Bayo Grande and breeding lines had better leaf spot resistance when compared to cultivars Georgia Green, MDR-98 and C-99R in all experiments across years. The addition of three or four fungicide applications to Bayo Grande and several of the breeding lines suppressed leaf spot to levels similar to those genotypes and Georgia Green under the full regime. Conservation tillage reduced the need for fungicides in most genotypes in both years. Yields were higher for Bayo Grande and the breeding lines compared to Georgia Green in three of the four experiments across years. When compared across genotype, yields were greatest for the full season fungicide regime, except in 2002 when yields were similar for all treatments. Leaf spot severity was reduced in conservation tillage compared to conventional tillage in most varieties in the absence of fungicides. However, yields tended to be lower in conservation tillage treatments than in conventional tillage. Under conservation tillage, yields of Bayo Grande and two of the breeding lines were negatively impacted in one year and were overall lower in the other year. Several of these new Bolivian-derived genotypes show promise for use in a reduced fungicide and/or conservation tillage IDM system with the potential to lessen fungicide use compared to standard production practices while maintaining low leaf spot levels and high yields.

Field Evaluations of Leaf Spot Resistance and Yield in Peanut Genotypes in the United States and Bolivia.

Field experiments were conducted in 2002 to 2006 to characterize yield potential and disease resistance in the Bolivian landrace peanut (Arachis hypogaea) cv. Bayo Grande, and breeding lines developed from crosses of Bayo Grande and U.S. cv. Florida MDR-98. Diseases of interest included early leaf spot, caused by the fungus Cercospora arachidicola, and late leaf spot, caused by the fungus Cercosporidium personatum. Bayo Grande, MDR-98, and three breeding lines, along with U.S. cvs. C-99R and Georgia Green, were included in split-plot field experiments in six locations across the United States and Bolivia. Whole-plot treatments consisted of two tebuconazole applications and a nontreated control. Genotypes were the subplot treatments. Area under the disease progress curve (AUDPC) for percent defoliation due to leaf spot was lower for Bayo Grande and all breeding lines than for Georgia Green at all U.S. locations across years. AUDPC for disease incidence from one U.S. location indicated similar results. Severity of leaf spot epidemics and relative effects of the genotypes were less consistent in the Bolivian experiments. In Bolivia, there were no indications of greater levels of disease resistance in any of the breeding lines than in Bayo Grande. In the United States, yields of Bayo Grande and the breeding lines were greater than those of the other genotypes in 1 of 2 years. In Bolivia, low disease intensity resulted in the highest yields in Georgia Green, while high disease intensity resulted in comparable yields among the breeding lines, MDR-98, and C-99R. Leaf spot suppression by tebuconazole was greater in Bolivia than in the United States. This result indicates a possible higher level of fungicide resistance in the U.S. population of leaf spot pathogens. Overall, data from this study suggest that Bayo Grande and the breeding lines may be desirable germplasm for U.S. and Bolivian breeding programs or production.

Differential gene expression in Arachis diogoi upon interaction with peanut late leaf spot pathogen, Phaeoisariopsis personata and characterization of a pathogen induced cyclophilin

The wild relatives of peanut are resistant to various economically important diseases including late leaf spot (LLS) caused by Phaeoisariopsis personata, compared with the susceptible cultivated peanut (Arachis hypogaea L.). The interaction of the late leaf spot pathogen, Phaeoisariopsis personata and the highly resistant, diploid peanut wild species, Arachis diogoi was analyzed at the molecular level by differential gene expression studies. Genes up-regulated with in 48h of pathogen challenge were isolated as partial cDNAs. Some of the isolated genes, which are shown to be involved in the first line of defense in plants, were further characterized with respect to their transcriptional regulation in response to pathogen. Among the isolated clones, two were found to encode cyclophilin like proteins. One of the two isolated partial cDNAs encoding cyclophilin like proteins was extended using 5' RACE. The full length cDNA, designated as AdCyp, was 886bp in length and encodes a polypeptide of 172 amino acids. Southern hybridization suggests that AdCyp is possibly coded by a single gene and at least one more identical gene is present in Arachis diogoi genome. AdCyp exhibits evolutionary conservation across the kingdoms. Phylogenetic analysis showed that AdCyp belongs to the subgroup I of Group I in cyclophilins. A translational fusion of GFP-AdCyp was found to localize to both cytosol and nucleus. AdCyp transcripts were found to accumulate in response to the treatments with pathogen as well as phytohormones. Constitutive heterologous expression of AdCyp resulted in enhanced resistance to Ralstonia solanacearum and reduced susceptibility towards Phytophthora parasitica var. nicotianae in transgenic tobacco and the resistance was associated with higher transcript levels of various defense related genes.

Registration of ‘Bailey’ Peanut

‘Bailey’ (Reg. No. CV‐111, PI 659502) is a large‐seeded virginia‐type peanut (Arachis hypogaea L. subsp. hypogaea var. hypogaea) with partial resistance to five diseases that occur commonly in the Virginia‐Carolina production area: early leaf spot (caused by Cercospora arachidicola Hori), late leaf spot [caused by Cercosporidium personatum (Berk. & M.A. Curtis) Deighton], Cylindrocladium black rot [caused by Cylindrocladium parasiticum Crous, M.J. Wingf. & Alfenas], Sclerotinia blight (caused by Sclerotinia minor Jagger), and tomato spotted wilt (caused by Tomato spotted wilt tospovirus). It also has partial resistance to southern stem rot (caused by Sclerotium rolfsii Sacc.). Bailey was developed as part of a program of selection for multiple‐disease resistance funded by growers, seedsmen, shellers, and processors. Bailey was tested under the experimental designation N03081T and was released by the North Carolina Agricultural Research Service (NCARS) in 2008. Bailey was tested by the NCARS, the Virginia Agricultural Experimental Station, and five other state agricultural experiment stations and the USDA‐ARS units participating in the Uniform Peanut Performance Tests. Bailey has an alternate branching pattern, an intermediate runner growth habit, medium green foliage, and high contents of fancy pods and medium virginia‐type seeds. It has approximately 34% jumbo and 46% fancy pods, seeds with tan testas and an average weight of 823 mg seed−1, and an extra large kernel content of approximately 42%. Bailey is named in honor of the late Dr. Jack E. Bailey, formerly the peanut breeding project's collaborating plant pathologist.

Late Leaf Spot Effects on Growth, Photosynthesis, and Yield in Peanut Cultivars of Differing Resistance

Cercosporidium personatum (Berk. & Curt.) Deighton causes late leaf spot (LLS) in peanut (Arachis hypogaea L.), which leads to necrotic lesions, early leaf senescence and yield losses. Detailed physiological analyses can contribute to an improved understanding of peanut‐disease interactions and cultivar improvement. A study was conducted evaluating two peanut cultivars with more (York) and less (Carver) quantitative resistance to C. personatum grown under fungicide‐sprayed and nonsprayed conditions in the field at Citra, FL over 2 yr. Data were collected on disease severity using the Florida 1 to 10 visual rating scale and by direct measurement of percent canopy lesion area. Leaf lifespan, total canopy photosynthesis (TCP), plant growth, and pod yield were also measured. Disease severity based on canopy lesion area was reduced by 30% in York compared to Carver. No additive effects of combining the resistant cultivar with fungicide were seen, as fungicide use increased yield by 364 kg ha−1 for both cultivars. Yield was more strongly related to disease severity based on canopy lesion area than to the Florida scale. Yield improvement with York was not as closely related to disease severity with only a 6% gain in pod yield in York compared to Carver. In addition, reduction in TCP was greater in York compared to Carver given their respective disease severity. These results indicated that combining resistance with the maintenance of physiological function during LLS infection could result in improved peanut yields under diseased conditions.