Eduardo Alano Vieira

Characterization of Carotenoid-protein Complexes and Gene Expression Analysis Associated with Carotenoid Sequestration in Pigmented Cassava (Manihot Esculenta Crantz) Storage Root.

Carotenoid-protein complex (CPC) was isolated from chromoplast-enriched suspensions of cassava storage root (CSR) using size exclusion chromatography and characterized. Peptide sequences (LC_MS/MS spectrum) obtained from CPC and their corresponding proteins were obtained using publically available databases. Small Heat Shock Proteins (sHSPs) were the most abundant proteins identified in the CPC. Western blot analysis showed that Fribrillin and Or-protein were present in chromoplast-enriched suspensions of yellow root but not in the complex or white root. Results from qRT-PCR helped identify an isoform of HSP21 possessing four single point mutations in the intense yellow CSR that may be responsible for increased sequestration of b-carotene.

Comparação entre medidas de distância genealógica, morfológica e molecular em aveia em experimentos com e sem a aplicação de fungicida

Estimatives of genetic dissimilarity between cultivars can be useful in a breeding program for directing crosses and evaluating the available germplasm. The objective of this work was to estimate the genetic dissimilarity between oat genotypes through AFLP markers and inbreeding coefficient and to intercorrelate these estimate with each other and with an estimate based on agronomical traits in experiments with and without fungicide application. Eleven oat cultivars were used to estimate the molecular genetic distance, from which nine were evaluated in the field to obtain the morphological estimatives. For the estimates of inbreeding coefficients, eight genotypes had known pedigree and were considered for the analyisis. A comparison of the matrices was obtained through a correlation analysis. Among the dissimilarity measures evaluated, the estimated distances based on molecular data and the inbreeding coefficient, were those evidencing the highest correlation (0.45). The second highest correlation was obtained between the morphological distances in experiments with and without fungicide application (0.44), no other correlation obtained was significant. Then, it is evident the presence of high genetic variability among the studied genotypes and the necessity of all three techniques to be used in a joined manner for obtaining a more precise estimate of genetic dissimilarity.

Adaptabilidade e estabilidade em aveia em ambientes estratificados

Twenty oat genotypes (Avena sativa L.) were evaluated for grain yield in the crop year of 2001 and 2002 in nine different locations in Parana, Rio Grande do Sul and Sao Paulo states, Brazil. The objectives of this work were to obtain adaptability and stability parameters estimates in favorable and unfavorable environments with and without fungicide application. The methodology of EBERHART & RUSSELL (1966) was applied. The significance for years, genotypes, fungicides and locals indicated a differential behavior of genotypes in favorable and unfavorable environments with and without fungicide application. Data analysis shows that fungicide application and the favorable and unfavorable environment affected intensely the parameters of adaptability (b1) and stability (s2di), indicating that these estimates must be performed in stratified environmental conditions, despite the fact that no ideal biotype was found, as predicted by the adopted model.

Genetic structure of annual ryegrass (Lolium multiflorum) populations estimated by RAPD

Annual ryegrass is a temperate climate annual foraging grass, grown mostly in the South of Brazil, especially in the state of Rio Grande do Sul. Despite its importance, little is known about its genetic diversity, both within and among the populations cultivated. This knowledge is of fundamental importance for developing breeding and conservation strategies. The aim of this study was to characterize the genetic diversity and structure of four populations of annual ryegrass. Three of the populations were located in Rio Grande do Sul and the fourth in Uruguay. RAPD markers were used to study the genetic diversity and structure of these populations. Analysis of 375 individuals sampled from the populations, using six RAPD primers, generated a total of 82 amplified bands. They included 73 polymorphic bands (89,02%). The value of the total genetic diversity index obtained, (0,71) was high, indicating the presence of wide genetic diversity in the four populations. Genetic structure analysis revealed that 98% of total diversity is intrapopulational, whereas interpopulational genetic diversity was only 2%. These results suggest that before these populations separated, they had gone through a period of gene exchange and, even after the separation event, gene frequency stayed at levels similar to the original levels, with no differential selection for these genes in the different cultivation areas.

Emprego de modelos gráficos na seleção de genitores de milho para hibridização e mapeamento genético

Associating phenotypic to molecular data can be a powerful tool for the selection of parental genotypes for breeding and mapping purposes. Thus, the objectives of the study were: i) to estimate the genetic dissimilarity among 30 maize inbred lines (15 tolerant and 15 sensitive to flooding); ii) to select potential parents for mapping and breeding; iii) to compare the efficiency of different graphical models in displaying the calculated distances. A total of 21 RAPD primers were used for the estimation of genetic dissimilarity. The genetic dissimilarity was obtained according to the complement of Dice similarity coefficient, clustering procedure was performed by the average linkage method and the cophenetic coefficient was obtained. The complement of Dice similarity coefficient was subjected to principal components and multidimensional scale analyses, and the output efficiency was tested by the correlation between the original distances and those presented in the graphs. The clustering techniques did not reveal a perfect agreement with the original matrix, with correlations of 0.70, 0.53 and 0.75 for the dendrogram, principal components and multidimensional scale analyses, respectively. Among the tested techniques employed, multidimensional scale analyses gave more precise outputs, since this technique showed higher agreement with the original distance matrix, and preserved distances between all genotype pairs. Besides, this technique is the most indicated when the objective is to plan crosses, since it displays the distances between genotype pairs.

Herança da resistência à ferrugem da folha da aveia (Puccinia coronata f. sp. avenae Fraser & Led.) em genótipos brasileiros de aveia branca

ABSTRACT Oat crown rust is the most important diseasefor the oat crop, occurring in practically all the areas whereoat is cultivated. The most indicated form of control forthis disease is the use of resistant cultivars. However, forthe durable resistance to be acquired, it is necessary toknow the genetics of resistance to crown rust in oats. Thus,the objective of this work was to determine the type ofinheritance of resistance to three Puccinia coronataf. sp.avenae Fraser & Led., isolates (collected in southern Brazil)in brazilian white oat genotypes. To determine theinheritance of resistance to each one of three isolates,F2populations were used generated through artificial crosses,between resistant (R) and susceptible (S) and betweenresistant genotypes (R). Thus, F2 populations from thefollowing artificial crosses: i) URPEL 15 (R) x UFRGS 7(S), UPF 16 (R) x UFRGS 7 (S) and URPEL 15 (R) x UPF16 (R), were used to determine the inheritance of resistanceto isolate one (1); ii) URPEL 15 (R) x UFRGS 7 (S), UPF18 (R) x UFRGS 7 (S) and URPEL 15 (R) x UPF 18 (R), todetermine the inheritance of resistance to isolate two (2);iii) URPEL 15 (R) x UFRGS 7 (S) and URPEL 15 (R) xUPF 18 (S), to determine the inheritance of resistance toisolate three (3). The obtained results indicate that thegenotype URPEL 15 present dominants genes for resistanceto the three oat leaf rust isolates evaluated, the cultivarUPF 16 presents a recessive gene for resistance to isolate 1and the cultivar UPF 18 has a recessive gene of resistenceto isolate 2. Also, the resistance genes presented bygenotypes URPEL 15, UPF 16 and UPF 18, segregate inan independent manner.

Early generation selection strategy for yield and yield components in white oat

Several studies have searched for higher efficiency on plant selection in generations bearing high frequency of heterozygotes. This work aims to compare the response of direct selection for grain yield, indirect selection through average grain weight and combined selection for higher yield potential and average grain weight of oat plants (Avena sativa L.), using the honeycomb breeding method. These strategies were applied in the growing seasons of 2001 and 2002 in F3 and F4 populations, respectively, in the crosses UPF 18 CTC 5, OR 2 ´ UPF 7 and OR 2 ´ UPF 18. The ten best genetic combinations obtained for each cross and selection strategy were evaluated in greenhouse yield trials. Selection of plants with higher yield and average grain weight might be performed on early generations with high levels of heterozygosis. The direct selection for grain yield and indirect selection for average grain weight enabled to increase the average of characters under selection. However, genotypes obtained through direct selection presented lower average grain weight and those obtained through the indirect selection presented lower yield potential. Selection strategies must be run simultaneously to combine in only one genotype high yield potential and large grain weight, enabling maximum genetic gain for both characters.