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1.
Curr Res Food Sci ; 5: 984-991, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35721394

RESUMO

The economic potential of the cactus species Cereus peruvianus Mill. (syn. C. hildmannianus K. Schum.) has already been demonstrated through the generation of products and patents. However, the phenolic compounds and antioxidant activity have not yet been evaluated. The aim of our study was to determine the total phenolic compounds, evaluate the antioxidant activity and characterize the phenolic compounds of cladode extracts from C. peruvianus grown in the southern region of Brazil, in two collection periods. Higher total content of phenolic compounds and antioxidant activity were detected in the cladode extract collected in 2016 than in the cladode extract collected in 2015. The profile of phenolic compounds identified five flavonoids that had not previously been reported in species of the genus Cereus. The phenolic compounds linked to antioxidant activities identified in the cladode extract from C. peruvianus support the use of this species in human food as a source of natural antioxidants.

2.
Curr Res Food Sci ; 5: 102-106, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35024623

RESUMO

The popping expansion is a characteristic that is positively related with the quality of popcorn. A positive correlation between the volume of expansion and the thickness of the pericarp, and between the proportion of the opaque/shiny endosperm and the grain weight and volume, were postulated. However, there are no reports in the literature that address the importance of cell wall components in the popping expansion. Here, we investigate the biochemical composition of the pericarp cell walls of three inbred lines of popcorn with different popping expansion. Inbred lines GP12 (expansion volume >40 mL g-1), P11 (expansion volume 30 mL g-1) and P16 (expansion volume 14 mL g-1) were used for the analysis and quantification of monosaccharides by HPAEC-PAD, and ferulic and p-coumaric acids and lignin by HPLC. Our hypothesis is that the biochemical composition of the pericarp cell walls may be related to greater or lesser popping expansion. Our data suggest that the lignin content and composition contribute to popping expansion. The highest concentration of lignin (129.74 µg mg-1; 12.97%) was detected in the pericarp cell wall of the GP12 inbred line with extremely high popping expansion, and the lowest concentration (113.52 µg mg-1; 11.35%) was observed in the P16 inbred line with low popping expansion. These findings may contribute to indicating the quantitative trait locus for breeding programs and to developing other methods to improve the popping expansion of popcorn.

3.
Braz J Microbiol ; 52(4): 2179-2192, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34491570

RESUMO

The composition of endophytic communities is dynamic and demonstrates host specificity; besides, they have great intra- and interspecific genetic variability. In this work, we isolated leaf endophytic fungi from Serjania laruotteana, identify them using multilocus analysis, and evaluate the genetic variability using IRAP (inter-retrotransposon amplified polymorphism) and REMAP (retrotransposon-microssatellite amplified polymorphism). A total of 261 fungi were isolated and 58 were identified. Multilocus phylogenetic analysis using the partial sequences from the ITS1-5.8S-ITS2 regions, elongation factor 1-alpha, ß-tubulin, actin, glyceraldehyde-3-phosphate dehydrogenase, and calmodulin genes identify that most strains belonged to the Colletotrichum and Diaporthe genera, other isolated genera were Xylaria, Phyllosticta, Muyocopron, Fusarium, Nemania, Plectosphaerella, Corynespora, Bipolaris, and Curvularia. The IRAP and REMAP analyzes were performed with Colletotrichum and Diaporthe genera and showed 100% of polymorphism and high intra- and interspecific variability. This is the first report of the diversity of endophytic fungi from S. laruotteana. In addition, it demonstrated that the IRAP and REMAP can be used to distinguish morphologically similar lineages, revealing differences even strains of the same species.


Assuntos
Biodiversidade , Fungos , Sapindaceae , Fungos/classificação , Fungos/genética , Tipagem de Sequências Multilocus , Filogenia , Retroelementos/genética , Sapindaceae/microbiologia
4.
J Ethnopharmacol ; 264: 113339, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32898627

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Cereus hildmannianus (K.) Schum. (syn. C. peruvianus) is a native medicinal plant in the Neotropical region. C. hildmannianus cladodes extracts are used in folk medicine for weight loss, reducing cholesterol, low-density lipoprotein (LDL) levels, as diuretic and cardiotonic, and to treat various diseases, including pulmonary disorders, rheumatism, and in topical treatment for wounds and lithiasis. Fruits and flowers of C. hildmmanianus have high nutritional value. AIM OF THE REVIEW: In this review, previous reports on C. hildmannianus (syn. C. peruvianus) concerning its botanical description, geographical distribution, ethnomedicinal use, phytochemistry, in vitro and in vivo pharmacological properties, food benefits and plant biotechnology were summarized. MATERIALS AND METHODS: Scientific search engines, including ScienceDirect, Capes Journals Portal, Google Scholar, PubMed, Scielo, and Scifinder, were consulted to gather data on C. hildmannianus. The present review is an up-to-date and comprehensive analysis of phytochemical compounds, ethnomedicinal uses, phytopharmacological activities, and food value of cladodes, flowers, fruits, seeds, and tissue culture from C. hildmannianus. RESULTS: In traditional medicine, C.hildmannianus is used to treat various diseases, including pulmonary disorders, rheumatism, and in topical treatment for wounds and lithiasis. The extracts from the cladodes of C. hildmannianus exhibited numerous in vitro and in vivo pharmacological activities such as gastroprotective, antioxidant, antifungal, ovicidal, hemagglutinating and slimming, and anticancer activity. These extracts' substances belong to different classes of chemical compounds such as fatty acids, polysaccharides, terpenes, alkaloids, phenolic acids, and flavonoids CONCLUSIONS: Ethnomedicinal surveys have indicated the use of C. hildmannianus, an important medicinal plant in South America, for the treatment of various diseases. The ethnobotanical, phytochemical, pharmacological, and ethnomedicinal properties from various morphological parts of the plant of C. hildmannianus were highlighted in this review, which provides information for future studies, commercial exploration and reveals that this plant has a huge potential for pharmaceutical and nutraceutical applications.


Assuntos
Cactaceae , Etnofarmacologia/métodos , Medicina Tradicional/métodos , Compostos Fitoquímicos/uso terapêutico , Extratos Vegetais/uso terapêutico , Plantas Medicinais , Animais , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Etnofarmacologia/tendências , Humanos , Medicina Tradicional/tendências , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , América do Sul/etnologia
5.
Breed Sci ; 70(4): 508-514, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32968355

RESUMO

Artificial selection related with important agronomic characteristics of Stevia rebaudiana may cause genetic divergence and formation of genetically structured populations with genetic uniformity or diversity within cultivars. Current study employed inter simple sequence repeats of DNA (ISSR markers) to assess genetic diversity within and among a single cultivated population maintained through sexual propagation (SR1) and four cultivated populations generated by artificial selection and maintained by vegetative propagation (SR2-SR5). Highest polymorphism rate was reported in SR1 (89.24%), whilst the lowest rate of polymorphism occurred in SR2 (60.13%). ISSR markers revealed that selection of plants with traits of vegetative-propagated interest may lead towards the generation of genetically more uniform DNA-level populations, while plants maintained by sexual propagation have high genetic variability. High estimated genetic divergence level indicated that the five areas of stevia form genetically structured populations. SR2 and SR4 are constituted by plants more homogeneous at DNA level for the selected characteristics than plants of SR3 and SR5 populations. Predominant and homogeneous genotypes selected at SR2 and SR4 areas could be valuable for tracing strategies to obtain stevia plants with the desirable agronomic characteristics through crosses between contrasting individuals in future breeding programs.

6.
PLoS One ; 13(6): e0199539, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29953466

RESUMO

Gray leaf spot is a maize foliar disease with worldwide distribution and can drastically reduce the production in susceptible genotypes. Published works indicate that resistance to gray leaf spot is a complex trait controlled by multiple genes, with additive effect and influenced by environment. The aim of this study was to identify genomic regions, including putative genes, associated with resistance to gray leaf spot under natural conditions of disease occurrence. A genome wide association study was conducted with 355,972 single nucleotide polymorphism markers on a phenotypic data composed by 157 tropical maize inbred lines, evaluated at Maringá -Brazil. Seven single nucleotide polymorphisms were significantly associated with gray leaf spot, some of which were localized to previously reported quantitative trait loci regions. Three gene models linked to the associated single nucleotide polymorphism were expressed at flowering time and tissue related with gray leaf spot infection, explaining a considerable proportion of the phenotypic variance, ranging from 0.34 to 0.38. The gene model GRMZM2G073465 (bin 10.07) encodes a cysteine protease3 protein, gene model GRMZM2G007188 (bin 1.02) expresses a rybosylation factor-like protein and the gene model GRMZM2G476902 (bin 4.08) encodes an armadillo repeat protein. These three proteins are related with plant defense pathway. Once these genes are validated in next studies, they will be useful for marker-assisted selection and can help improve the understanding of maize resistance to gray leaf spot.


Assuntos
Resistência à Doença/genética , Doenças das Plantas/genética , Zea mays/genética , Estudo de Associação Genômica Ampla , Modelos Genéticos , Fenótipo , Proteínas de Plantas/genética , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas
7.
Acta sci., Biol. sci ; 37(4): 463-469, Oct.-Dec. 2015. ilus
Artigo em Inglês | LILACS | ID: biblio-875832

RESUMO

Current analysis characterizes the effect of different fungicides often applied for pest control on α−and ß-esterase patterns of four economically important table-wine grape cultivars (Italia, Rubi, Benitaka and Brasil) of Vitis vinifera. The α- and ß-esterase patterns in bud leaves of the cultivars were assessed by native PAGE analysis. Cabrio Top® compound inhibited EST-2, EST-5, EST-6, EST-7, EST-8, EST-9 and EST-10 carboxylesterases, whereas EST-4, EST-11, EST-12, EST-13, EST-14 acetylesterases and EST-16 carboxylesterase were detected as weakly stained bands. Carboxylesterases and acetylesterases were also detected as weakly stained bands when exposed to fungicides Orthocide 500®, Positron Duo® and Folicur PM®. No changes in α- and ß-esterase patterns were reported when the vines were exposed to the fungicides Rovral SC®, Kumulus DF®, Curzate M®, Score® or Cuprogarb 500®. The evidence of functional changes in carboxylesterase and acetylesterase levels in current study is a warning to grape producers on the dangers inherent in the indiscriminate use of potent and modern fungicides extensively used in agriculture. The inhibition effect of fungicides on esterase isozyme molecules seems to be independent of the fungicide chemical.


O presente estudo caracterizou o efeito de diferentes fungicidas comumente aplicados como medidas de controle de pragas sobre padrões de α- e ß-esterases de quatro importantes cultivares de uva de mesa (Itália, Rubi, Benitaka e Brasil) de Vitis vinifera. Os padrões de α- e ß-esterases de brotos foliares das cultivares foram avaliados por PAGE. O composto Cabrio Top® inibiu as carboxilesterases EST-2, EST-5, EST-6, EST-7, EST-8, EST-9 e EST-10, enquanto as acetilesterases EST-4, EST-11, EST-12, EST-13, EST-14 e a carboxilesterase EST-16 foram detectadas como bandas fracamente coradas. As carboxilesterases e acetilesterases também foram detectadas como bandas fracamente coradas quando expostas aos fungicidas Orthocide 500®, Positron Duo® e Folicur PM®. Não foram observadas alterações nos padrões de α- e ß-esterases quando as videiras foram expostas aos fungicidas Rovral SC®, Kumulus DF®, Curzate M®, Score® ou Cuprogarb 500®. A evidência de alterações em nível funcional em carboxilesterases e acetilesterases, apresentada neste estudo, pode servir como um alerta aos produtores de uva dos perigos inerentes ao uso indiscriminado de fungicidas potentes e modernos amplamente utilizados hoje na agricultura. O efeito dos fungicidas sobre as enzimas esterases parece ser independente do grupo químico ao qual pertence o fungicida.


Assuntos
Vitis , Esterases , Isoenzimas
8.
Appl Biochem Biotechnol ; 175(2): 965-73, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25351629

RESUMO

High and low polymorphisms in simple sequence repeats of expressed sequence tag (EST-SSR) for specific proteins and enzymes, such as ß-amylase, cellulose synthase, xyloglucan endotransglucosylase, fructose 1,6-bisphosphate aldolase, and fructose 1,6-bisphosphatase, were used to illustrate the genetic divergence within and between varieties of sugarcane (Saccharum spp.) and to guide the technological paths to optimize ethanol production from lignocellulose biomass. The varieties RB72454, RB867515, RB92579, and SP813250 on the second stage of cutting, all grown in the state of Paraná (PR), and the varieties RB92579 and SP813250 cultured in the PR state and in Northeastern Brazil, state of Pernambuco (PE), were analyzed using five EST-SSR primers for EstC66, EstC67, EstC68, EstC69, and EstC91 loci. Genetic divergence was evident in the EstC67 and EstC69 loci for ß-amylase and cellulose synthase, respectively, among the four sugarcane varieties. An extremely high level of genetic differentiation was also detected in the EstC67 locus from the RB82579 and SP813250 varieties cultured in the PR and PE states. High polymorphism in SSR of the cellulose synthase locus may explain the high variability of substrates used in pretreatment and enzymatic hydrolysis processes, which has been an obstacle to effective industrial adaptations.


Assuntos
Etanol/metabolismo , Glucosiltransferases/metabolismo , Indústrias , Repetições de Microssatélites/genética , Polimorfismo Genético , Saccharum/enzimologia , beta-Amilase/metabolismo , Biomassa , Etiquetas de Sequências Expressas/metabolismo , Loci Gênicos/genética , Glucosiltransferases/genética , Hidrólise , Lignina/metabolismo , Saccharum/genética , Saccharum/metabolismo , beta-Amilase/genética
9.
Mol Biotechnol ; 53(3): 300-7, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22467122

RESUMO

In the present study, we analyze the genetic structure and diversity among accessions of popcorn obtained from the CIMMYT International Maize and Wheat Improvement Center that represent the diversity available for current use by breeding programs. The main objectives were to identify SSR loci that were the best indicators of genetic diversity, to measure the genetic diversity within popcorn genotypes, and to analyze the genetic structure of the promising populations destined for use in breeding programs. The mean gene diversity of all SSR loci was 0.6352. An extremely high population differentiation level was detected (F(st) = 0.3152) with F(st) for each locus ranging from 0.1125 (Umc1229) to 0.4870 (Umc1755). Analyzing the genetic structure of eight popcorn accessions was especially important for identifying both SSR loci with high levels of heterozygosity and genotypes showing high heterozygosity (BOYA462 and ARZM13 050). This analysis should be the medium and long-term selection goal for the generation of inbred lines and the future production of new cultivars. Plant accessions ARZM05 083, ARZM13 050, and URUG298 may also be useful varieties that exhibit important agronomic characteristics that can be used through crosses to broaden the genetic basis of popcorn.


Assuntos
DNA de Plantas/isolamento & purificação , Zea mays/genética , Alelos , Cruzamento , DNA de Plantas/genética , Loci Gênicos , Variação Genética , Heterozigoto , Repetições de Microssatélites , Polimorfismo Genético , Análise de Sequência de DNA
10.
Biochem Genet ; 49(3-4): 270-82, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21221761

RESUMO

The genetic structure of Cereus peruvianus populations descended from cultivated plants (F(1) populations) and from plants regenerated in vitro (R(1) populations) was analyzed using α- and ß-esterase isozymes in native PAGE. The estimated proportion of polymorphic loci was higher (50%) in the R(1) populations than the F(1) populations (42.85%). The mean observed (0.5599) and expected (0.5620) heterozygosity in R(1) descendents was also higher than the rates in F(1) descendents (H (o) = 0.4142; H (e) = 0.4977). A low level of population differentiation was detected in R(1) descendents (F (st) = 0.05). In contrast, population differentiation was high in F(1) descendents (0.2583). Esterase analysis using PAGE showed that artificial selection by silvicultural management provides high genetic diversity and a large genetic basis for C. peruvianus, whereas in vitro selection from callus tissue culture involves an increase of heterozygosity levels in descendents from somaclones and a low level of interpopulational divergence.


Assuntos
Cactaceae/genética , Esterases/genética , Polimorfismo Genético , Cactaceae/enzimologia , Marcadores Genéticos , Isoenzimas/genética , Brotos de Planta/enzimologia
11.
Braz. arch. biol. technol ; 53(2): 389-396, Mar.-Apr. 2010. ilus, tab
Artigo em Inglês | LILACS | ID: lil-546570

RESUMO

The objective of this study was to evaluate the genetic diversity and the parental contribution of Piaractus mesopotamicus in the production of offspring in the semi-natural system of reproduction. Twenty parental fishes (eleven males and nine females) and the total of 100 larvae were evaluated by microsatellite marker. The parents and offspring had thirty-one alleles and heterozygosity of 0.550 and 0.563, respectively. The females were fertilised by two up to six males while the males fertilised three up to five females. The contribution of the females and males to the offspring were 66.6 and 58 percent, respectively. Such results indicated no loss in the genetic variability in the offspring, and the parents had multiple paternity and reasonable contribution to the offspring production.


O objetivo deste trabalho foi avaliar a diversidade genética e a contribuição parental de Piaractus mesopotamicus na produção de descendência no sistema seminatural de reprodução. Vinte peixes parentais (onze machos e nove fêmeas) e o total de 100 larvas foram avaliados por meio do marcador microssátelite. Os parentais e a progênie tiveram trinta e um alelos e heterozigosidade de 0,550 e 0,563, respectivamente. As fêmeas foram fertilizadas por dois até seis machos enquanto machos fertilizaram três até cinco fêmeas. A contribuição de fêmeas e machos para a descendência seja 66,6 e 58,0 por cento, respectivamente. Tais resultados não indicam diminuição da variabilidade genética na progênie e os parentais apresentaram paternidade múltipla e razoável contribuição à produção de descendência.

12.
Electron. j. biotechnol ; 13(1): 4-5, Jan. 2010. ilus, tab
Artigo em Inglês | LILACS | ID: lil-559587

RESUMO

Information about genetic dissimilarity is very important to corroborate genealogical relationships and to predict the most heterozygotic hybrid combinations. Eight popcorn S6 lines of diverse germplasm types were evaluated using simple sequence repeats (SSR) markers. Of a total of 51 evaluated polymorphic primers, 15 were used for polymerase chain reaction (PCR) amplification. The genetic distance was estimated by Rogers’ modified distance. The different popcorn breeding programs in Brazil are possibly using highly similar base-populations. The genetic similarity of lines P1-3 and P8-1 was lowest, while P3-3 and P8-2 were genetically more similar. The cophenetic correlation showed that the Unweighted Pair-Group Method Using Arithmetic Averages (UPGMA) was reliable to discriminate the genotypes in five groups. The clusters were consistent with the estimates of genetic identity. There was a moderate coincidence degree between the groups and genealogy of lines. Higher levels of heterozygosity are expected from crosses between the group containing lines P3-3 and P7-3 with that of P1-3 and P7-4. Crosses between lines P1-3 and P8-1 are also promising.


Assuntos
Polimorfismo Genético/genética , Variação Genética/genética , Zea mays/crescimento & desenvolvimento , Zea mays/genética , Amplificação de Genes/genética , Genótipo , Repetições Minissatélites
13.
Biosci. j. (Online) ; 24(4): 86-93, oct.-dec. 2008. ilus
Artigo em Português | LILACS | ID: lil-545518

RESUMO

Alterações ambientais provocadas pelas mudanças climáticas e principalmente por ações humanastêm reduzido populações naturais de peixes nos últimos anos. Os programas de repovoamento têm sido utilizados como forma de conservação, porém, sem uma correta orientação científica essas medidas podem gerar distúrbios sobre a diversidade genética da ictiofauna e sobre o ecossistema. O objetivo deste estudo foi analisar a diversidade genética de dois estoques de alevinos de Prochilodus lineatus utilizados em programas de repovoamento, mediante o marcadormolecular RAPD. Foram analisados 60 alevinos (estoque A e B) de uma piscicultura localizada no município de Rolândia, PR (Brasil). Os sete iniciadores selecionados produziram um total de 77 fragmentos, dos quais 81,82% foram polimórficos. Os valores de variabilidade genética estimados pela porcentagem de fragmentos polimórficos (A= 83,12%;B= 81,82%) e pelo índice de diversidade genética de Shannon (A= 0,473; B= 0,463) mostraram que não existe uma alta diferenciação genética entre os dois estoques, possivelmente devido ao efeito fundador e ao manejo reprodutivo. Este resultado foi corroborado com o valor de Gst (0,043), do dendrograma e da distância e identidade genética (0,967 e 0,034)que mostram uma baixa diferenciação genética entre eles. Os resultados deste estudo possibilitarão o correto manejoreprodutivo e genético dos estoques e a orientação objetiva de programas de repovoamento, permitindo a conservação da ictiofauna e dos ecossistemas impactados.


Environmental alterations caused by the climatic changes and mainly for human actions, it hasbeen reducing fish natural populations in the last years. The stocking programs have been used as conservation form,however, without a correct scientific orientation those measured can generate disturbances about the genetic diversity of the ichthyofauna and on the ecosystem. The objective of this study was to analyze the genetic diversity of two juvenile Prochilodus lineatus stocks used in stocking programs, by the RAPD molecular marker. Sixty juvenile (A and B stocks) of a fish farm located in the Rolândia Municipal District, PR (Brazil) were analyzed. The seven primers selected produced a total of 71 fragments, of which 89.44% were polymorphic. The genetic variability values estimated by the percentage ofpolymorphic fragments (A = 83.12%; B = 81.82%) and for the genetic diversity of Shannon index (A = 0.473; B = 0.463) showed that a high genetic differentiation doesn't exist among the two stocks, possibly due to the founder effect and the reproductive management. This result was corroborated with the Gst value (0.043), of the dendrogram and of the distance and genetic identity (0.967 and 0.034) that show a low genetic differentiation among them. The results of this study will make possible the correct reproductive and genetic management stocks and the objective orientation at of stocking programs, allowing the ichthyofauna and the impact ecosystems conservation.


Assuntos
Animais , Fauna Aquática , Mudança Climática , Ecossistema , Peixes , Variação Genética , Genética , Técnica de Amplificação ao Acaso de DNA Polimórfico
14.
Electron. j. biotechnol ; 11(1): 41-49, Jan. 2008. ilus, graf, tab
Artigo em Inglês | LILACS | ID: lil-522159

RESUMO

Isozyme biochemical marker may be useful tool for genomic analysis of maize populations undergoing recurrent selection. Thus, isozymes markers was utilized for assess the changes in the genetic variability and distance in a Brazilian composite population of popcorn following four cycles of recurrent selection for yield. One hundred and ninety-six half-sib families were evaluated from each cycle and the ten highest-yielding families (5.2 percent) were recombined to produce the next cycle. Isozyme analysis considered 80 seedlings per cycle. Simple linear regression equations were estimated among the allele frequencies in each locus in function of the selection cycles, the genetic distances among the cycles and the average heterozygosity per locus for each cycle. Regression analysis did not reveal any common trend for changes in allele frequencies presumably due to selection. The estimates of the number of polymorphic locus, of the mean of allele per locus and the mean heterozygosity did not reveal any reduction in variability. It was concluded that four selection cycles did not cause relevant changes in the variability or genetic distance among the selection cycles of CMS-43 popcorn population. Isozymes markers analysis showed that the number of recombined half-sib families in recurrent selection was suitable.


Assuntos
Marcadores Genéticos , Heterozigoto , Malato Desidrogenase (NADP+) , Zea mays/genética , Eletroforese em Gel de Poliacrilamida , Locos de Características Quantitativas
15.
Hereditas ; 139(2): 96-106, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-15061810

RESUMO

Microsatellites have become the most important class of markers for mapping procedures. Primarily based on restriction fragment length polymorphism (RFLP) markers, several molecular genetic maps of maize have been developed, mainly using temperate inbred maize lines. To characterize the level of polymorphism of microsatellite loci and construct a genetic map in tropical maize, two elite inbred lines, L-08-05F and L-14-4B, were crossed to produce 400 F(2) individuals that were used as a mapping population. A survey of 859 primer pair sequences of microsatellites was used. The polymorphism screens of each microsatellite and genotype assignment were performed using high-resolution agarose gels. About 54 % of the primer sets gave clearly scorable amplification products, 13 % did not amplify and 33 % could not be scored on agarose gels. A total of 213 polymorphic markers were identified and used to genotype the mapping population. Among the polymorphic markers, 40 showed loci deviating from expected Mendelian ratios and clusters of deviating markers were located in three chromosome regions. Non-Mendelian scoring was present in 19 markers. The final genetic map with 117 markers spanned 1634 cM in length with an average interval of 14 cM between adjacent markers.


Assuntos
Marcadores Genéticos , Repetições de Microssatélites/genética , Zea mays/genética , Ligação Genética , Polimorfismo Genético
16.
Hereditas ; 139(2): 107-15, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-15061811

RESUMO

A previous genetic map containing 117 microsatellite loci and 400 F(2) plants was used for quantitative trait loci (QTL) mapping in tropical maize. QTL were characterized in a population of 400 F(2:3) lines, derived from selfing the F(2) plants, and were evaluated with two replications in five environments. QTL determinations were made from the mean of these five environments. Grain yield (GY), plant height (PH), ear height (EH) and grain moisture (GM) were measured. Variance components for genotypes (G), environments (E) and GxE interaction were highly significant for all traits. Heritability was 0.69 for GY, 0.66 for PH, 0.67 for EH and 0.23 for GM. Using composite interval mapping (CIM), a total of 13 distinct QTLs were identified: four for GY, four for PH and five for EH. No QTL was detected for GM. The QTL explained 32.73 % of the phenotypic variance of GY, 24.76 % of PH and 20.91 % of EH. The 13 QTLs displayed mostly partial dominance or overdominance gene action and mapped to chromosomes 1, 2, 7, 8 and 9. Most QTL alleles conferring high values for the traits came from line L-14-4B. Mapping analysis identified genomic regions associated with two or more traits in a manner that was consistent with correlation among traits, supporting either pleiotropy or tight linkage among QTL. The low number of QTLs found, can be due to the great variation that exists among tropical environments.


Assuntos
Repetições de Microssatélites/genética , Locos de Características Quantitativas , Zea mays/genética , Água/química , Zea mays/química , Zea mays/crescimento & desenvolvimento
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