Marcia Flores da Silva Ferreira

Mapeamento de QTL para conteúdos de proteína e óleo em soja

The objective of this study was to detect and map quantitative trait loci (QTL) affecting soybean (Glycine max L. Merr.) protein and oil contents. F2 plants, derived from the cross between the CS3032PTA276 line and the variety UFVS2012, were grown in a greenhouse and provided the leaves for DNA extraction and analysis. Forty-eight polymorphic microsatelite markers (SSR) were evaluated in the F2 population. Evaluation of the phenotype was performed in 207 families from F2:3 progenies, in a complete block design with three replicates, carried out in Vicosa, MG, Brazil, in 2006. Four QTL associated with protein content, in linkage groups D1a, G, A1, and I, and three QTL for oil content in groups A1, I and O were identified. Phenotypic variation for protein and oil explained by QTL ranged from 6.24 to 18.94% and 17.26 to 25.93%, respectively. New QTL associated with protein and oil contents were detected, besides those previously reported in other studies. Other regions may be involved in the genetic control of protein and oil contents in soybean besides those already known.

Toxicity of Difenoconazole and Tebuconazole in Allium cepa

Macroscopic (germination and root growth) and microscopic (mitotic index, chromosome, and nuclear aberrations) analyses have been used to determine the toxicity of environmental pollutants. To better understand the molecular mechanisms of mutation and their effects, molecular markers offer a key perspective, as they measure the direct effects of DNA mutagenic agents. The aim of this study was to evaluate the toxic potential of the fungicides difenoconazole (DZ) and tebuconazole (TZ) on Allium cepa. A reduction was observed in the germination, root growth, and mitotic index at higher concentrations of DZ and TZ, compared to the negative control. In addition, high incidence of chromosome and nuclear aberrations was detected in treated roots. This demonstrates the genotoxic, cytotoxic, and phytotoxic effects of DZ and TZ on the root tips of A. cepa. Moreover, the molecular results indicate a change in the amplification profiles of the simple sequence repeats (SSR) and intersimple sequence repeats (ISSR) obtained from A. cepa after exposure to the tested compounds. Loss and gain of bands increased dose-dependently. Further, the grouping methods distinguished the higher concentrations from the negative control. The ISSR and SSR analyses proved to be efficient tools for evaluating DNA alterations caused by DZ and TZ. In association with macroscopic and microscopic analyses, they constitute an informative approach for environmental mutagen studies.

Transferability of Microsatellites from Psidium guajava to Eugenia, Myrciaria, Campomanesia, and Syzygium Species (Myrtaceae)

Myrtaceae has many fruit-bearing species of economic and ecological relevance worldwide, but with microsatellite molecular markers (simple sequence repeats, SSR) available for only few of them. Thus, the transferability of SSR is advantageous for characterization, conservation, and breeding of these species. In this work, 158 SSR from Psidium guajava were evaluated for transferability in 18 fruit trees of the genera Eugenia, Campomanesia, Myrciaria, and Syzygium. Of those, 152 SSR transferred to at least 1 and up to 16 species; 47 SSR amplified in more than 10 species, the most conserved; and 13 SSR transferred to 1 or 2 species, demonstrating specificity. A large number of conserved SSR are also present in the genetic map of P. guajava, and may be helpful for synteny and comparative genomic studies. The average of transferability was lower for Syzygium and similar in the other genera. Transferability in the species varied from 20 SSR for Syzygium cumini to 91 for Myrciaria sp.2, being higher on average in the genus Eugenia. Clustering based on the pattern of transferability between species revealed two groups, one composed by Eugenia and Campomanesia and another by Syzygium and Myrciaria, which indicates conserved microsatellite regions within and between genera. This study also allowed selection of the most suitable SSR for each species and genus by amplification quality and study type, thus contributing for a better comprehension of the relationships between the species, taxonomy, structure and genetic diversity, construction of genetic maps, and breeding and conservation programs in the family.

CORRELAÇÕES GENÉTICAS E ANÁLISE DE TRILHA PARA CARACTERES DE FRUTO DA PALMEIRA JUÇARA

The palm tree Euterpe edulis is a native species from Mata Atlântica and it is nowadays found in the list of species which are threatened by extinction. One option to withdraw it from this list would be the stimulation of the commercial planting aiming the management of fruits which receive the “super fruit” classification by their chemical and nutritional properties. However, one stage of extreme importance that precedes the superior genotypes selection is the study of associations among the variables, because it allows delineating alternate selection strategies to maximize the gains. The present study had as objective to estimate the genetic correlations by the REML/BLUP procedure and the direct and indirect effects upon fruit mass by path analysis for six fruit characters of 198 accessions of E. edulis. Fruits of 198 Jucara genotypes collected in 20 forestry fragments in the south and Caparao region of the state of Espirito Santo were analyzed. From each genotype 25 fruits were evaluated for the characteristics: longitudinal and equatorial fruit and seed diameter; fruit and seed mass. The obtained data were used for genetic correlations estimative through the method of restricted maximum likelihood and better unbiased linear prediction (REM/BLUP). Subsequently, the genetic correlations among the fruit variables were submitted to path analysis. The six fruit characters studied show positive genetic association with magnitude higher than 0.71 by the REML/BLUP procedure. The longitudinal diameter of fruit and seed mass have greater direct effect on fruit weight, which makes them most indicated to increase the chances of success in the Jucara genotypes selection with larger fruit . The characteristics longitudinal diameter of fruit and the seed mass are the main determinants of changes in the mass of fruit.

Diversidade genética de seleções de goiabeiras Cortibel

Brazil is one of the largest producers of guava, Psidium guajava L., of the world. Orchards from seminal propagation, owing to cross-pollination, result in large variability, allowing the selection of genotypes for crop improvement. The aim of this essay was to study the genetic diversity of genotypes selected from seminal origin orchard (named Cortibel I to XIII) and compare them to Paluma and Pedro Sato and Roxa genotype (purchased in nursery), by morphological and quality of fruit characteristics. There was divergence between Cortibel selections. Cortibel I was the most divergent between red pulp genotypes and between all the others, showing the best performance for fruit characteristics. CVIII and CIV genotypes obtained the best performance between light pulp genotypes. Cortibel selections presented similar performance about fruit quality to commercial crops, providing good material for use as new cultivars or for hybridizations in breeding programs.

Refinement of the karyological aspects of Psidium guineense (Swartz, 1788): a comparison with Psidium guajava (Linnaeus, 1753).

Abstract Euploidy plays an important role in the evolution and diversification of Psidium Linnaeus, 1753. However, few data about the nuclear DNA content, chromosome characterization (morphometry and class) and molecular markers have been reported for this genus. In this context, the present study aims to shed light on the genome of Psidium guineense Swartz, 1788, comparing it with Psidium guajava Linnaeus, 1753. Using flow cytometry, the nuclear 2C value of Psidium guineense was 2C = 1.85 picograms (pg), and the karyotype showed 2n = 4x = 44 chromosomes. Thus, Psidium guineense has four chromosome sets, in accordance with the basic chromosome number of Psidium (x = 11). In addition, karyomorphometric analysis revealed morphologically identical chromosome groups in the karyotype of Psidium guineense. The high transferability of microsatellites (98.6%) further corroborates with phylogenetic relationship between Psidium guajava and Psidium guineense. Based on the data regarding nuclear genome size, karyotype morphometry and molecular markers of Psidium guineense and Psidium guajava (2C = 0.95 pg, 2n = 2x = 22 chromosomes), Psidium guineense is a tetraploid species. These data reveal the role of euploidy in the diversification of the genus Psidium.

Chemotype diversity of Psidium guajava L.

The essential oil of Psidium guajava L. has been studied for pharmacological and industrial purposes, without considering the plants genotype regarding the heterogeneity of its composition. The present study aimed to characterize the chemotype diversity of the essential oil extracted from the leaves of 22 genotypes of P. guajava grown in two different environments in the state of Espírito Santo, Brazil, and to identify the different chemical markers present in these plants. Essential oil from the leaves of the P. guajava genotypes was extracted by hydrodistillation, and its chemical composition was analyzed by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Thirty-three compounds were identified, comprising 87.5-99.0% of the total composition, with a prevalence of sesquiterpenes in all samples. The major compounds identified consisted of (E)-trans-Caryophyllene, α-Humulene, trans-Nerolidol, β-Bisabolene, β-Bisabolol, and Hinesol, the first of which was identified as a possible chemical marker for the species. Multivariate factor analysis of the chemical composition of P. guajava oil identified three chemotypes: Commercial - PAL, SEC, PS, PET, C7, C11, and C17MI, characterized by high levels of β-Selinene, α-Selinene, Hinesol, and 14-hydroxy-epi-(E)-caryophyllene, with β-Selinene and α-Selinene as the chemical markers; C10 and C13, exhibiting high levels of Elemol, trans-Nerolidol, trans-β-Eudesmol, and (2Z, 6Z)-Farnesol, which were indicated as chemical markers, and Cortibel - C1, C2, C3, C4, C5, C6, C8, C9, C12, C14, C15, C16, C17LI, which retained high levels of α-Cedrene, cis-α-Bergamotene, α-Humulene, Humulene epoxide, epi-α-Cadinol, β-Bisabolol, and α-Bisabolol, with β-Bisabolol and α-Bisabolol as the chemical markers. The use of guava genotypes with different chemotypes, that are agronomically favorable to fruit production and essential oil exploitation adds value to the crop and renders it more sustainable. Given guava crops produce large amounts of leaf biomass, resulting from successive prunings, the extraction of their essential oil, which retains commercially valuable compounds, can be feasible.

Transferability of Psidium microsatellite loci in Myrteae (Myrtaceae): a phylogenetic signal

Myrteae is the most diverse tribe, in number of species and genera, of the family Myrtaceae, representing half of the family’s biodiversity. Analysis of universal cross-transferable genetic markers across genera/species is essential and may significantly contribute towards the better understanding of species systematics and evolution. In the present study, a total of 133 sequence-tagged microsatellite markers from Psidium guajava L. were evaluated for transferability to forty-four species of the tribe Myrteae, which represent nine different genera of the family Myrtaceae (Myrciaria, Plinia, Pimenta, Acca, Campomanesia, Psidium, Eugenia, Syzygium, and Eucalyptus). Cross-transferable simple sequence repeat (SSR) markers were employed to evaluate the phylogenetic relationships between them. The results indicated a high level of congruence with earlier reports regarding genetic divergence and taxa clustering. An analysis to optimize the number of SSR markers was also performed, revealing that even a small amount is capable of determining the systematic positions of different genera/species of the Myrteae tribe.

Mutagenic effects of spent potliner and derivatives on Allium cepa L. and Lactuca sativa L.: A molecular approach

Spent potliner (SPL) is a solid residue generated by the aluminum industry. Its composition is variable and complex, containing fluoride and cyanide salts as well as aluminum, which contributes to its toxicity. SPL is sometimes released directly into the soil, where it is prone to leaching and has the potential to cause alterations and damage to DNA. Considering that polymorphism analysis of simple sequence repeat (SSR) and inter-simple sequence repeat (ISSR) DNA markers is an interesting tool to determine the mutagenicity of an environmental pollutant, the present study adopted this approach to verify the mutagenic potential of SPL and its main toxic components (aluminum, fluoride, and cyanide) on root tip cells of Lactuca sativa and Allium cepa. Alterations in ISSR and SSR regions were identified by DNA fingerprinting (gain and loss of bands and changes in band intensity). The estimated dissimilarities indicated differences between treatments and the negative control. Furthermore, the relationship between the amplification profile of the markers and alterations in cell mitosis was discussed.

Morphophysiology, Phenotypic and Molecular Diversity of Auxin-induced Passiflora mucronata Lam. (Passifloraceae)

Genetic diversity allows identification of potential intraspecific genotypes in the genus Passiflora. The objective of this study was to examine the morphological and genetic diversity of auxin-induced Passiflora mucronata. The experiments were arranged in a complete randomized block design, with a 9 x 2 factorial arrangement (nine genotypes x presence and absence of auxin, indole-3-butyric acid (IBA)), with four replicates of 16 cuttings. The rooting and vegetative growth responses were variable. Genotype 5 was more responsive in the absence of IBA and genotypes 3, 8 and 9 were more responsive in the presence of IBA. Auxin increased rooting rate and percentage, reducing the average time of root protrusion in eight days. IBA also contributed to increase photosynthesis and dry root and shoot mass in 55.55 and 44.44% of the genotypes, respectively. The highest relative contribution to phenotypic diversity in the absence of auxin was rate (38.75%) and percentage (20.27%) of rooting, whereas in the presence of auxin was stomatal conductance (23.19%) and root dry mass (20.91%). Similarity was found for phenotypic and molecular divergence in the presence of IBA, in which genotypes 1 and 6; genotypes 5, 8 and 9; and genotype 3 were clustered in distinct groups.