Molecular characterization and pathogenicity of isolates of Beauveria spp. to fall armyworm

The objective of this work was to evaluate the pathogenicity of 24 Beauveria isolates to Spodoptera frugiperda larvae, and characterize them molecularly through rDNA-ITS sequencing and RAPD markers. Sequencing of rDNA-ITS fragments of 570 bp allowed the identification of isolates as B. bassiana or B. brongniarti by sequence comparison to GenBank. Sixty seven polymorphic RAPD fragments were capable to differentiate 20 among 24 Beauveria isolates, grouping them according to the derived host insect and to pathogenicity against maize fall armyworm larvae. Three RAPD markers were highly associated to the pathogenicity against S. frugiperda, explaining up to 67% of the phenotypic variation. Besides identification and molecular characterization of Beauveria isolates, ITS sequence and RAPD markers proved to be very useful in selecting the isolates potentially effective against S. frugiperda larvae and in monitoring field release of these microorganisms in biocontrol programs.

Breeding, genetic and genomic of citrus for disease resistance

Although the citriculture is one of the most important economic activities in Brazil, it is based on a small number of varieties. This fact has contributed for the vulnerability of the culture regarding the phytosanitary problems. A higher number of varieties/genotypes with potential for commercial growing, either for the industry or fresh market, has been one of the main objectives of citrus breeding programs. The genetic breeding of citrus has improved, in the last decades, due to the possibility of an association between biotechnological tools and classical methods of breeding. The use of molecular markers for early selection of zygotic seedlings from controlled crosses resulted in the possibility of selection of a high number of new combination and, as a consequence, the establishment of a great number of hybrids in field experiments. The faster new tools are incorporated in the program, the faster is possibility to reach new genotypes that can be tested as a new variety. Good traits should be kept or incorporate, whereas bad traits have to be excluded or minimized in the new genotype. Scion and rootstock can not be considered separately, and graft compatibility, fruit quality and productivity are essential traits to be evaluated in the last stages of the program. The mapping of QTLs has favored breeding programs of several perennial species and in citrus it was possible to map several characteristics with qualitative and quantitative inheritance. The existence of linkage maps and QTLs already mapped, the development of EST and BAC library and the sequencing of the Citrus complete genome altogether make very demanding and urgent the exploration of such data to launch a wider genetic study of citrus. The rising of information on genome of several organisms has opened new approaches looking for integration between breeding, genetic and genome. Genome assisted selection (GAS) involves more than gene or complete genome sequencing and is becoming an import support in breeding programs of annual and perennial species. An huge information amount can be derivate from genome analysis. The use and benefit of such informations will depend on the genetic basis of the breeding program.

FRUIT MORPHOLOGY AND PRODUCTIVITY OF BABASSU PALMS IN NORTHERN MINAS GERAIS STATE, BRAZIL1

ABSTRACT The objectives of this study were to morphologically characterize fruits of the babassu palm tree (Attalea vitrivir) and to estimate their productivity in the north of Minas Gerais State, Brazil. Twenty mature fruits were collected from 10 plants in three different areas in Januária, Minas Gerais. Eighteen biometric parameters of the fruits were measured, the oil contents of the seeds was determined, the adherence to normal distribution was evaluated, distribution frequencies were evaluated and the effects of individuals and areas on the variables and the correlations between them were analyzed. The production of fruit bunches per plant and the number of fruits per bunch from 10 plants were quantified in three areas and the potential production under both natural harvesting and cultivation conditions were estimated. Significant differences were found among all of the biometric parameters examined between the different individuals and the different areas, which shows wide morphological variability in the fruits. The average oil content was 45.7%, but with significant differences among individuals. The observed variability favors the selection of productive individuals in genetic improvement programs. The potential productivity of endocarps and oil based on a density of 400/plants per hectare would be respectively 6.4 and 1.2 tons/ha, which indicates the possibility of using A. vitrivir for producing charcoal, bio fuels, and for carbon fixation.

Construction and validation of a surgical skills assessment tool for general surgery residency program

Objective: To develop and validate an instrument for measuring the acquisition of technical skills in conducting operations of increasing difficulty for use in General Surgery Residency (GSR) programs. Methods: we built a surgical skills assessment tool containing 11 operations in increasing levels of difficulty. For instrument validation we used the face validaity method. Through an electronic survey tool (Survey MonKey(r)) we sent a questionnaire to Full and Emeritus members of the Brazilian College of Surgeons - CBC - all bearers of the CBC Specialist Title. Results: Of the 307 questionnaires sent we received 100 responses. For the analysis of the data collected we used the Cronbach's alpha test. We observed that, in general, the overall alpha presented with values near or greater than 0.70, meaning good consistency to assess their points of interest. Conclusion: The evaluation instrument built was validated and can be used as a method of assessment of technical skill acquisition in the General Surgery Residency programs in Brazil.

Serum neutralization with different types and subtypes of bovine herpesvirus 1 and 5

The serum neutralization (SN) test is the gold standard method to measure neutralizing antibodies to bovine herpesviruses. However, in view of the further subdivisions of bovine herpesviruses in types/subtypes, defining which virus to use at challenge in SN tests may be difficult. In view of that, this study was carried out to re-evaluate (SN) sensitivity with different types/subtypes of bovine herpesviruses types 1 (BoHV-1) and 5 (BoHV-5) as challenge viruses. Bovine sera (n=810) were collected from two distinct geographic regions and tested by SN with three type 1 viruses (BoHV-1.1 strains "Los Angeles" and "EVI123/98"; BoHV-1.2a strain "SV265/96") and three type 5 viruses (BoHV-5a strain "EVI88/95"; BoHV-5b strain "A663" and BoHV-5c "ISO97/95"). SN tests were performed with a 1 hour incubation of the serum-virus mixtures at 37ºC against 100 TCID50 of each of the viruses. SN sensitivity varied greatly depending on the challenge virus used in the test. The highest sensitivity (327 positive/810 total sera tested; 40.37%) was attained when the positive results to the six viruses were added together. No association could be found between any particular type or subtype of virus and the sensitivity of the test. When positive results to each single strain were considered, SN sensitivity varied from 41.7% to 81.7%, depending on the virus and the geographic region of origin of the sera. Variation was detected even when challenge viruses belonged to the same subtype, where disagreement between positive results reached 41%. These results indicate that one hour incubation SN tests against single viruses, as performed here, may display a significantly low sensitivity (p=0.05); performing SN tests against a number of different viruses may increase considerably SN sensitivity. Furthermore, the choice of virus used for challenge is critical in SN tests. In addition, sera from different geographic regions may give rise to disagreeing results with different strains of BoHV-1 and BoHV-5. This might be particularly relevant for control programs and in international trade, were maximum sensitivity should be targeted.

Initial growth and development of southern sandbur based on thermal units

Availability of basic information on weed biology is an essential tool for designing integrated management programs for agricultural systems. Thus, this study was carried out in order to calculate the base temperature (Tb) of southern sandbur (Cenchrus echinatus), as well as fit the initial growth and development of the species to accumulated thermal units (growing degree days - GDD). For that purpose, experimental populations were sown six times in summer/autumn conditions (decreasing photoperiod) and six times in winter/spring condition (increasing photoperiod). Southern sandbur phenological evaluations were carried out, on alternate days, and total dry matter was measured when plants reached the flowering stage. All the growth and development fits were performed based on thermal units by assessing five base temperatures, as well as the absence of it. Southern sandbur development was best fit with Tb = 12 ºC, with equation y = 0,0993x, where y is the scale of phenological stage and x is the GDD. On average, flowering was reached at 518 GDD. Southern sandbur phenology may be predicted by using mathematical models based on accumulated thermal units, adopting Tb = 12 ºC. However, other environmental variables may also interfere with species development, particularly photoperiod.

Effect of high and low molecular weight glutenin subunits, and subunits of gliadin on physicochemical parameters of different wheat genotypes

Identification of functional properties of wheat flour by specific tests allows genotypes with appropriate characteristics to be selected for specific industrial uses. The objective of wheat breeding programs is to improve the quality of germplasm bank in order to be able to develop wheat with suitable gluten strength and extensibility for bread making. The aim of this study was to evaluate 16 wheat genotypes by correlating both glutenin subunits of high and low molecular weight and gliadin subunits with the physicochemical characteristics of the grain. Protein content, sedimentation volume, sedimentation index, and falling number values were analyzed after the grains were milled. Hectoliter weight and mass of 1000 seeds were also determined. The glutenin and gliadin subunits were separated using polyacrylamide gel in the presence of sodium dodecyl sulfate. The data were evaluated using variance analysis, Pearson's correlation, principal component analysis, and cluster analysis. The IPR 85, IPR Catuara TM, T 091015, and T 091069 genotypes stood out from the others, which indicate their possibly superior grain quality with higher sedimentation volume, higher sedimentation index, and higher mass of 1000 seeds; these genotypes possessed the subunits 1 (Glu-A1), 5 + 10 (Glu-D1), c (Glu-A3), and b (Glu-B3), with exception of T 091069 genotype that possessed the g allele instead of b in the Glu-B3.

Physical purity and germination of sugarcane seeds (caryopses) (Saccharum spp.)

Plant breeding is generally done through sexual reproduction even when the species is propagated asexually for commercial exploitation, as for example, in sugarcane. Therefore, the development of procedures to evaluate sugarcane seed viability is important for plant breeding programs. The objective of this research was to develop a methodology for analyzing the viability of sugarcane seeds (Saccharum spp.). Three crosses were used, two biparental crosses and one polycross. For the germination test study, two substrates (paper and sand) and three constant incubation temperatures (25 ºC, 30 ºC and 35 ºC), in the presence of constant light and also an alternating temperatures (20-30 ºC), with 8 hours light (30 ºC) and 16 hours darkness (20 ºC), were studied. Seedlings were evaluated every five days. The results demonstrated that temperature affected sugarcane seed germination with the most favorable conditions being the alternating temperature (20-30 ºC) and the constant temperature of 30 ºC on a paper substrate.