Comparative Genomics Suggests that the Fungal Pathogen Pneumocystis Is an Obligate Parasite Scavenging Amino Acids from Its Host's Lungs.

Pneumocystis jirovecii is a fungus causing severe pneumonia in immuno-compromised patients. Progress in understanding its pathogenicity and epidemiology has been hampered by the lack of a long-term in vitro culture method. Obligate parasitism of this pathogen has been suggested on the basis of various features but remains controversial. We analysed the 7.0 Mb draft genome sequence of the closely related species Pneumocystis carinii infecting rats, which is a well established experimental model of the disease. We predicted 8'085 (redundant) peptides and 14.9% of them were mapped onto the KEGG biochemical pathways. The proteome of the closely related yeast Schizosaccharomyces pombe was used as a control for the annotation procedure (4'974 genes, 14.1% mapped). About two thirds of the mapped peptides of each organism (65.7% and 73.2%, respectively) corresponded to crucial enzymes for the basal metabolism and standard cellular processes. However, the proportion of P. carinii genes relative to those of S. pombe was significantly smaller for the "amino acid metabolism" category of pathways than for all other categories taken together (40 versus 114 against 278 versus 427, P<0.002). Importantly, we identified in P. carinii only 2 enzymes specifically dedicated to the synthesis of the 20 standard amino acids. By contrast all the 54 enzymes dedicated to this synthesis reported in the KEGG atlas for S. pombe were detected upon reannotation of S. pombe proteome (2 versus 54 against 278 versus 427, P<0.0001). This finding strongly suggests that species of the genus Pneumocystis are scavenging amino acids from their host's lung environment. Consequently, they would have no form able to live independently from another organism, and these parasites would be obligate in addition to being opportunistic. These findings have implications for the management of patients susceptible to P. jirovecii infection given that the only source of infection would be other humans.

A guide for easy- and difficult-to-treat hypertension.

Although the blood pressure (BP) of many patients can be controlled using standard combinations, treatment of hypertension frequently represents a clinical challenge to the primary care physician. This article will review best practices for managing patients with easy- and difficult-to-treat hypertension, including preferred antihypertensive combinations, optimizing adherence and persistence, recognizing white-coat hypertension, and intensifying therapy for treatment-resistant patients. Each physician must decide based on his or her own level of experience at what point a patient becomes too challenging and would benefit from referral to a hypertension specialist for more intensive management and to complete the exclusion of secondary forms of arterial hypertension. With intensive pharmacotherapy, many patients with difficult-to-treat hypertension can achieve BP control. If it fails, interventional strategies (e.g., renal denervation) are a valid option to get BP controlled.

Self-measurement of blood pressure in clinical trials and therapeutic applications

Self-measurement of blood pressure (SMBP) is increasingly used to assess blood pressure outside the medical setting. A prerequisite for the wide use of SMBP is the availability of validated devices providing reliable readings when they are handled by patients. This is the case today with a number of fully automated oscillometric apparatuses. A major advantage of SMBP is the great number of readings, which is linked with high reproducibility. Given these advantages, one of the major indications for SMBP is the need for evaluation of antihypertensive treatment, either for individual patients in everyday practice or in clinical trials intended to characterize the effects of blood-pressure-lowering medications. In fact, SMBP is particularly helpful for evaluating resistant hypertension and detecting white-coat effect in patients exhibiting high office blood pressure under antihypertensive therapy. SMBP might also motivate the patient and improve his or her adherence to long-term treatment. Moreover, SMBP can be used as a sensitive technique for evaluating the effect of antihypertensive drugs in clinical trials; it increases the power of comparative trials, allowing one to study fewer patients or to detect smaller differences in blood pressure than would be possible with the office measurement. Therefore, SMBP can be regarded as a valuable technique for the follow-up of treated patients as well as for the assessment of antihypertensive drugs in clinical trials.

An Investigation of Emulsion Stabilized Limestone Screenings, HR-309, 1994

A significant amount of waste limestone screenings is produced during aggregate production. This waste material cannot be used in highway construction because it does not meet current highway specifications. The purpose of this research was to determine if a waste limestone screenings/emulsion mix could be used to construct a base capable of supporting local traffic. A 1.27 mile (2.04 km) section of roadway in Linn County was selected for this research. The road was divided into seven sections. Six of the sections were used to test 4 in. (100 mm) and 6 in. (150 mm) compacted base thicknesses containing 2.5%, 3.5%, and 4.5% residual asphalt contents. The seventh section was a control section containing untreated waste limestone screenings. This research on emulsion stabilized limestone screenings supports the following conclusions: (1) A low maintenance roadway can be produced using a seal coat surface on 6 in. (150 mm) of stabilized limestone screenings with 4.5% asphalt cement; (2) A 6 in. (150 mm) emulsion stabilized base with less than 3.5% asphalt cement does not produce a satisfactory low cost maintenance roadway; (3) A 4 in. (100 mm) emulsion stabilized base does not produce a satisfactory low cost maintenance roadway; and (4) A 2 in. (50 mm) asphalt concrete surface would be necessary on many roads to provide a low maintenance roadway using emulsion stabilized limestone screenings.

Lipoxygenase 2 and the early steps of jasmonic acid biosynthesis in "Arabidopsis thaliana"

Résumé Les oxylipines, telles que l'acide jasmonique (AJ ou jasmonate), jouent un rôle central en réponse à la blessure et à la pathogenèse. De nombreuses études ont montré l'importance de la voie canonique du jasmonate lors de la défense des plantes. De plus, un précurseur cyclopentenone de l'AJ, l'acide oxo-phyto-dienoic (OPDA), a été impliqué comme jouant le rôle d'une molécule signal lors de la défense contre certains pathogènes. En utilisant des mutants bloqués dans la biosynthèse de l'acide jasmonique (aos) ou dans sa perception (coi1-1), nous avons cherché à définir dans quelle mesure l'OPDA joue un rôle de signal induisant l'expression génétique en réponse à la blessure chez Arabidopsis. A l'aide de puces à ADN (microarray), nous avons montré que les transcriptomes d'aos et de coi1-1 sont très semblables après blessure, ce qui suggère que les produits d'AOS sont tous perçus via COI1. Pourtant, lorsqu'on analyse les métabolites présents chez ces mutants, une différence est visible, puisque aos n'accumule pas d'AJ, alors que coi1-1 en accumule encore rapidement après blessure. Nous avons étudié la possibilité qu'un mécanisme de régulation post-traductionnelle sur la voie de biosynthèse du jasmonate explique l'accumulation d'AJ chez coi1-1 après blessure. La lipoxygenase 2 (LOX2) est la première enzyme impliquée dans la biosynthèse de l'AJ et est donc une cible potentielle d'un tel mécanisme. Un indice sur la manière dont l'activité LOX pourrait être régulée vient du mutant fou2 (pour fatty acid oxygenation upregcilated 2) dans lequel l'activité LOX ainsi que le niveau d'AJ sont constitutivement élevés. Cette mutation implique un flux de cation dans la régulation de la production de l'AJ. De plus, il a été montré que plusieurs LOXs, dans des organismes autres que des plantes, peuvent lier le calcium. Nous montrons que l'activité LOX requiert l'addition de cations divalents pour être maximale in vitro, et que non seulement le calcium mais aussi le magnésium joue ce rôle. De plus, nous caractérisons un mutant récessif de LOX2 chez Arabidopsis (lox2-1). Ces plantes sont fertiles, et une analyse quantitative montre qu'elles accumulent toujours un peu d'AJ après blessure. Ceci suggère que LOX2 n'est pas la seule LOX impliquée dans la synthèse d'AJ. Aussi les plantes lox2-1 ne sont pas plus sensibles que les plantes de type sauvage lorsqu'elles sont infectées par la moisissure Botrytis cinerea ou lorsqu'elles sont exposées à un détritivore, néanmoins elles sont plus sensibles lorsqu'elles sont offertes en nourriture à un insecte herbivore. Les insectes et les plantes ont co-évolué conjointement, ainsi une plante ne contenant qu'un niveau réduit d'AJ favorise l'insecte. La disponibilité d'un mutant avec un niveau intermédiaire d'AJ va permettre de mieux comprendre pourquoi les plantes produisent autant de jasmonate. Abstract Oxylipins such as jasmonic acid (JA) play central roles in the wound response and during pathogenesis and many studies have confirmed the important role of the canonical jasmonate pathway in plant defense. Moreover, the cyclopentenone precursor of JA, oxo-phytodienoic acid (OPDA), is also thought to function as a signaling molecule in defense towards some pathogens. Its action was reported to depend on a different signal pathway to JA. By using mutants blocked in the biosynthesis (aos) or perception (coil-1) of JA, we investigated to which extend OPDA works as signaling molecule to trigger gene expression in the wound response of Arabidopsis. Using microarrays, we showed that aos and coil-1 transcriptome are similar in response to wounding, suggesting that products of AOS are all perceived by COI1. However, we found a difference between the two mutants at the metobolomic level, since aos is devoid of JA, but coil-1 can still rapidly accumulate JA upon wounding. We investigated the possibility that the post-translational activation of JA biosynthesis could explain the fast accumulation of JA in coil-1 plants upon wounding. Lipoxygenase (LOX) 2 is the first enzyme implicated in JA synthesis and was thus chosen as a potential target for posttranslational regulation. A clue as to how LOX activity might be regulated came from the fatty acid oxygenation upregulated 2 (foul) mutant in which LOX activity and JA levels are elevated. The foul mutant implicates cations flux in the regulation of JA production, and several LOXs in organisms other than plants have been shown to bind calcium. We showed that Arabidopsis LOX requires divalent cations for full activity in vitro, and that not only calcium but also magnesium can play this role. Moreover, a single recessive mutant of AtLOX2 was characterized. These plants are fully fertile. Quantitative oxylipin analysis showed that lox2-1 can still accumulate some JA after wounding, which suggests that LOX2 is not the only LOX involved in JA biosynthesis. lox2-1 plants do not show altered susceptibility to the fungus Botrytis cinerea or to a detritivore, however, they are more susceptible to an insect herbivore. The insect and plants are closely co-evolved and a reduced ability to synthesize JA favors the insect. The availability of a lox2-1 mutant with intermediate JA levels will further help understanding why plants produce elevated JA levels.

Bond Enhancement Techniques for PCC Whitetopping, HR-341, 1996

This research was initiated in 1991 as a part of a whitetopping project to study the effectiveness of various techniques to enhance bond strength between a new portland cement concrete (PCC) overlay and an existing asphalt cement concrete (ACC) pavement surface. A 1,676 m (5,500 ft) section of county road R16 in Dallas County was divided into 12 test sections. The various techniques used to enhance bond were power brooming, power brooming with air blast, milling, cement and water grout, and emulsion tack coat. Also, two sections were planed to a uniform cross-section, two pavement thicknesses were placed, and two different concrete mix proportions were used. Bond strength was perceived to be the key to determining an appropriate design procedure for whitetopping. If adequate bond is achieved, a bonded PCC overlay technique can be used for design. Otherwise, an unbonded overlay procedure may be more appropriate. Conclusions are as follows: (1) Bond Strength Differences - Milling increased bond strength versus no milling. Tack coat showed increased bond strength versus no tack coat. Planing, Air Blast and Grouting did not provide noticeable improvements in bond strength; nor did different PCC types or thicknesses affect bond strength significantly. (2) Structure - Structural measurements correlated strongly with the wide variation in pavement thicknesses. They did not provide enough information to determine the strength of bonding or the level of support being provided by the ACC layer. Longitudinal cracking correlated with PCC thicknesses and with planing. (3) Bond Over Time - The bond between PCC and ACC layers is degrading over time in the outside wheel path in all of the sections except tack coat (section 12). The bond strength in the section with tack coat was lower than the others, but remained relatively steady.

Asphalt Emulsions for Highway Construction, HR-216, 1985

A 5.8 mile section of Dubuque County (Iowa) Road D-53 was selected for this project, the objective of which were to: 1. identify a cost effective asphalt emulsion bound macadam typical cross section; 2. determine the effectiveness of engineering fabric placed under macadam roadbeds; and 3. evalaute the use of emulsions in surface seal coats. A number of conclusions were reached: 1. The minus #200 sieve material for the macadam stone should be held to a minimum. For the emulsion used on this project, the minus #200 material had less than 4 percent to achieve satisfactory coating of the macadam stone. 2. The placement of the emulsion treated macadam required no additional equipment or time than the plain macadam placement. 3. Emulsion treating the macadam stone for the shoulder base appears unnecessary. 4. The emulsion treated macadam base beneath an asphaltic concrete wearing surface yielded a higher structural rating than the plain macadam beneath a comparable ashaltic concrete surface. 5. The performance of the fabric between the subgrade and the macadam base to prevent soil intrusion into the base could not be determined by the non-destructive testing conducted. 6. When no choke stone is used over the macadam base, allowance for ac mix overrun should be made. 7. Use of an emulsion instead of a cutback asphalt saved money and energy. However, the poor performance of the seal coat negated any real savings.

Changes in arbuscular mycorrhizal fungal phenotypes and genotypes in response to plant species identity and phosphorus concentration.

* Arbuscular mycorrhizal fungi (AMF) are plant symbionts that improve floristic diversity and ecosystem productivity. Many AMF species are generalists with wide host ranges. Arbuscular mycorrhizal fungi individuals are heterokaryotic, and AMF populations are genetically diverse. Populations of AMF harbor two levels of genetic diversity on which selection can act, namely among individuals and within individuals. Whether environmental factors alter genetic diversity within populations is still unknown. * Here, we measured genetic changes and changes in fitness-related traits of genetically distinct AMF individuals from one field, grown with different concentrations of available phosphate or different host species. * We found significant genotype-by-environment interactions for AMF fitness traits in response to these treatments. Host identity had a strong effect on the fitness of different AMF, unearthing a specificity of response within Glomus intraradices. Arbuscular mycorrhizal fungi individuals grown in novel environments consistently showed a reduced presence of polymorphic genetic markers, providing some evidence for host or phosphate-induced genetic change in AMF. * Given that AMF individuals can form extensive hyphal networks colonizing different hosts simultaneously, contrasting habitats or soil properties may lead to evolution in the population. Local selection may alter the structure of AMF populations and maintain genetic diversity, potentially even within the hyphal network of one fungus.

Thin Maintenance Surfaces - Phase II, TR-435, 2003

In recent years there has been renewed interest in using preventive maintenance techniques to extend pavement life and to ensure low life cycle costs for our road infrastructure network. Thin maintenance surfaces can be an important part of a preventive maintenance program for asphalt cement concrete roads. The Iowa Highway Research Board has sponsored Phase Two of this research project to demonstrate the use of thin maintenance surfaces in Iowa and to develop guidelines for thin maintenance surface uses that are specific to Iowa. This report documents the results of test section construction and monitoring started in Phase One and continued in Phase Two. The report provides a recommended seal coat design process based on the McLeod method and guidance on seal coat aggregates and binders. An update on the use of local aggregates for micro-surfacing in Iowa is included. Winter maintenance guidelines for thin maintenance surfaces are reported herein. Finally, Phase One's interim, qualitative thin maintenance surface guidelines are supplemented with Phase two's revised, quantitative guidelines. When thin maintenance surfaces are properly selected and applied, they can improve the pavement surface condition index and the skid resistance of pavements. For success to occur, several requirements must be met, including proper material selection, design, application rate, workmanship, and material compatibility, as well as favorable weather during application and curing. Specific guidance and recommendations for many types of thin maintenance surfaces and conditions are included in the report.

Design and establishment of a biobank in a multicenter prospective cohort study of elderly patients with venous thromboembolism (SWITCO65+).

In the field of thrombosis and haemostasis, many preanalytical variables influence the results of coagulation assays and measures to limit potential results variations should be taken. To our knowledge, no paper describing the development and maintenance of a haemostasis biobank has been previously published. Our description of the biobank of the Swiss cohort of elderly patients with venous thromboembolism (SWITCO65+) is intended to facilitate the set-up of other biobanks in the field of thrombosis and haemostasis. SWITCO65+ is a multicentre cohort that prospectively enrolled consecutive patients aged ≥65 years with venous thromboembolism at nine Swiss hospitals from 09/2009 to 03/2012. Patients will be followed up until December 2013. The cohort includes a biobank with biological material from each participant taken at baseline and after 12 months of follow-up. Whole blood from all participants is assayed with a standard haematology panel, for which fresh samples are required. Two buffy coat vials, one PAXgene Blood RNA System tube and one EDTA-whole blood sample are also collected at baseline for RNA/DNA extraction. Blood samples are processed and vialed within 1 h of collection and transported in batches to a central laboratory where they are stored in ultra-low temperature archives. All analyses of the same type are performed in the same laboratory in batches. Using multiple core laboratories increased the speed of sample analyses and reduced storage time. After recruiting, processing and analyzing the blood of more than 1,000 patients, we determined that the adopted methods and technologies were fit-for-purpose and robust.

Evaluation of Cover Aggregate Stripping Characteristics, HR-182, 1979

The purpose of Research Project HR-182 was to identify those aggregate types which would perform satisfactorily as seal coat aggregates. Aggregates were chosen from across the State to represent the various types normally encountered and were used with two different types of binder bitumens. A water spray treatment was also included to simulate the effects of rainfall. The evaluation was based upon aggregate retention. Due to the influence of unexpected variables upon the field samples, the laboratory data are reliable for only the most general observations. Namely, that gravels as a group appear to be retained better than carbonates and rain-fall shortly after seal coat placement can affect aggregate retention. The subsequent field observations and analysis of skid resistance data permit the following conclusions: 1. Aggregate retention is influenced by lithologic type with the gravels, quartzite, haydite, dolomites, and medium grained limestones performing best. 2. Aggregate retention is not influenced by binder bitumen type. 3. Friction values of seal coats are influ-enced by aggregate retention and/or lithologic type. The following recommendations have been determined: The aggregate used for cover aggregate/seal coat projects should be Type 4 or better skid resistance as identified in Iowa DOT Materials Instructional Memorandum T-203. This will result in maximizing the possibility of good aggregate retention and skid resistance.

Cognate peptide-receptor ligand mapping by directed phage display

Background: A rapid phage display method for the elucidation of cognate peptide specific ligand for receptors is described. The approach may be readily integrated into the interface of genomic and proteomic studies to identify biologically relevant ligands.Methods: A gene fragment library from influenza coat protein haemagglutinin (HA) gene was constructed by treating HA cDNA with DNAse I to create 50 ¿ 100 bp fragments. These fragments were cloned into plasmid pORFES IV and in-frame inserts were selected. These in-frame fragment inserts were subsequently cloned into a filamentous phage display vector JC-M13-88 for surface display as fusions to a synthetic copy of gene VIII. Two well characterized antibodies, mAb 12CA5 and pAb 07431, directed against distinct known regions of HA were used to pan the library. Results: Two linear epitopes, HA peptide 112 ¿ 126 and 162¿173, recognized by mAb 12CA5 and pAb 07431, respectively, were identified as the cognate epitopes.Conclusion: This approach is a useful alternative to conventional methods such as screening of overlapping synthetic peptide libraries or gene fragment expression libraries when searching for precise peptide protein interactions, and may be applied to functional proteomics.

Effect of two dosages of Metarhizium anisopliae var. acridum against Rhammatocerus schistocercoides Rehn

The fungus Metarhizium anisopliae var. acridum, strain CG 423, was tested under field conditions against the gregarious grasshopper Rhammatocerus schistocercoides (Rehn) (Orthoptera: Acrididae). Conidia formulated in a racemic mixture of soybean oil and kerosene were sprayed under field conditions using an ultralow-volume hand-held atomizer Ulva Plus adjusted to deliver 2.9 L/ha. Bands composed of 2nd instar nymphs were treated with either 5.0x10(12) or 1.0x10(13) viable conidia/ha. The number of insects in each band was estimated at day one following spraying and by the end of the field trial (15 to 16 days post-treatment). Reductions in population size reached, in average, 65.8% and 80.4% for bands treated with the higher and lower dosage, respectively. For both dosages, total mortality rates of insects collected at two days post-application, and kept in cages for 14 days under lab conditions, showed no significant differences as compared to that obtained with insects collected immediately after spraying. Healthy insects were fed to native grasses sprayed on the field with 1.0x10(13) viable conidia/ha. Mortality levels of the nymphs fed on grasses collected two and four days post-application were not affected when compared to nymphs fed on grasses collected immediately following application.

Effects of the relatedness of arbuscular mycorrhizal fungi on associated species ecology

More than 80 % of vascular plants in the world form symbioses with arbuscular mycorrhizal fungi (AMF). AMF supply plants with nutrients such as phosphate and nitrogen, and can also help the plants to take up water. Hence, the symbiosis can greatly influence the growth and the defence of plants. By modifying plant productivity and diversity, AMF are considered as keystone species in ecosystems, playing a role that ultimately affects many food webs. This is why mycorrhizal symbioses have been investigated for several decades by many research groups.¦However, a large part of the scientific research done on AMF symbiosis has focused on the interaction between one plant and one fungus. This situation is far from realistic, as in natural ecosystems, many different fungal strains and species are co-existing and interacting in a belowground network. The main goal of this PhD was to investigate first, the interaction occurring among different co-existing AMF depending on their genetic relatedness and second, the outcome of the interaction and their effects on associated species.¦We found that AMF genetic relatedness partly explains the interaction among AMF, and this was in agreement with theories made for completely different species. Briefly, we demonstrated that AMF isolates of the same species coexisted more easily when they were closely-related, whereas AMF from different species were more in competition in this case of high relatedness. We also demonstrated that coexistence and competition among AMF can mediate plant growth as well as herbivore behaviour, opening new insights in our understanding of AMF effects on ecosystem functioning.¦Overall, the results of the different experiments of this PhD highlight the necessity of using multiple AMF to understand their interactions. Even so, we demonstrated here that simple species richness is not enough to understand these interactions and genetic relatedness among the co-existing AMF is a parameter that must be taken into account.¦-¦Sur Terre, plus de 80 % des plantes vasculaires forment des symbioses avec des champignons endomycorhiziens à arbuscules (CEA). Ces CEA permettent aux plantes d'acquérir plus facilement des nutriments tels que des phosphates, des nitrates, ou simplement de l'eau. Ainsi, cette symbiose peut avoir un effet important à la fois sur la croissance mais aussi sur la défense des plantes. En modulant la productivité et la diversité des plantes, les CEA sont donc des espèces clefs dans l'écosystème. Leur présence peut avoir des répercussions sur l'ensemble des réseaux trophiques. C'est pourquoi de nombreuses équipes de recherches étudient ces symbioses mycorhizienes depuis plusieurs décennies.¦La plupart des études concernant ces symbioses se sont focalisées sur l'action d'une espèce de CEA sur une espèce de plante. Malheureusement, cette situation ne correspond pas à ce que l'on peut retrouver dans la nature, où de nombreuses souches et de nombreuses espèces de CEA coexistent et interagissent dans un réseau mycélien souterrain. Le principal but de cette thèse était d'étudier, premièrement les interactions entre les différent CEA en fonction de leur apparentement génétique, et deuxièmement, d'étudier l'effet de ces interactions fongiques sur l'écologie des espèces associées.¦Au cours des différentes expériences de cette thèse, nous avons démontré que l'apparentement génétique entre les CEA expliquait une part non négligeable de leurs interactions. En résumé, plus l'apparentement génétique entre des souches de CEA d'une même espèce sera grand, plus ces souches seront capables de coexister. En revanche, s'il s'agit d'espèces différentes de CEA, plus elles seront apparentées, plus la compétition sera grande entre elles. Nous avons également démontré que la coexistence et la compétition entre différents CEA peut modifier à la fois la croissance des plantes mais aussi le comportement de leur prédateurs, ce qui ouvre de nouvelles perspectives sur notre compréhension des effets des CEA dans le fonctionnement des écosystèmes.¦Globalement, les résultats de nos différentes expériences mettent en évidence la nécessité d'utiliser plusieurs souches ou espèces de CEA pour mieux comprendre leurs interactions. Quand bien même, nos expériences démontrent que le simple recensement du nombre d'espèces de CEA n'est pas suffisant pour comprendre les interactions et que l'apparentement génétique des CEA coexistants est un paramètre qui doit être pris en compte.

Diallel analysis for frogeye leaf spot resistance in soybean

Seven soybean cultivars (Bossier, Cristalina, Davis, Kent, Lincoln, Paraná and Uberaba), with different levels of resistance to Cercospora sojina, were crossed in a diallel design to determine the general (GCA) and specific (SCA) combining abilities relative to the inheritance of the resistance. Race 04 of the fungus was inoculated in the parents and in the 21 F1 hybrids in a greenhouse in a completely randomized design, with 12 replications. The reactions to the disease were evaluated 20 days after the inoculation, always on the most infected leaflet. Both GCA and SCA were significant for all the evaluated characters, being inferred that, for the expression of the characters, the additive, dominant and, possibly, epistatic genic actions were important. The largest values of estimated SCA effect (ij) were observed in the hybrid combinations where at least one parent presented high GCA. Cristalina, Davis and Uberaba cultivars showed the largest estimates for GCA effect (i), and from the analysis of ii, the contribution of these parents to heterosis of their hybrids will be towards the reduction of the disease symptoms. Therefore, these cultivars are indicated as parents in breeding programs that seek the development of soybean cultivars with resistance to frogeye leaf spot.