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71.
Characterization of dinucleotide and trinucleotide EST-derived microsatellites in the wheat genome 总被引:6,自引:0,他引:6
Over the past decade microsatellites or simple sequence repeats (SSRs) have attracted a considerable amount of attention from
researchers. The aim of the present paper was to analyse expressed sequence tag-derived SSR (EST-SSR) marker variability in
wheat and to investigate the relationships between the number and type of repeat units and the level of microsatellite polymorphism.
Two hundred and forty-one new EST-SSR markers available in a public database () were characterized in eight durum wheat cultivars (Svevo, Ciccio, Primadur, Duilio, Meridiano, Claudio, Latino, Messapia),
two accessions of Triticum turgidum var. dicoccoides (MG4343, MG29896), one accession of T. turgidum var. dicoccum (MG5323) and in the common wheat cv. Chinese Spring. Of these, 201 primer pairs (83.4%) amplified PCR products successfully,
while the remaining 40 (16.6%) failed to amplify any product. Of the EST-SSRs analysed, 45.2% of the primer pairs amplified
one or two PCR products. Multiple discrete PCR products were observed among both di- and trinucleotide EST-SSR markers (31.2
and 40.5%, respectively). Markers based on dinucleotide microsatellites were more polymorphic than those based on trinucleotide
SSRs in the 12 wheat genotypes tested (68.9 and 52.7%, respectively). An average of 2.5 alleles for dinucleotide and 2.0 alleles
for trinucleotide SSRs was observed. The data reported in the present work indicate the presence of a significant relationship
between motif sequence types and polymorphism. The primer set based on the AG repeat motif showed the lowest percentage of
polymorphism (55.0%), while the primer set based on the AC repeat motif showed t he highest percentage (85.0%). Among trinucleotide
SSRs, the AGG microsatellite markers showed the highest percentage of polymorphism (70.0%), and the ACG motif the lowest value
(25.0%). The characterization of these new EST-SSR markers and the results of our studyon the effect of repeat number and
type of motifs could have important applications in the genetic analysis of agronomically important traits, quantitative trait
locus discovery and marker-assisted selection. 相似文献
72.
Implications of early selection for grain colour on iron and zinc content and productivity of common bean 下载免费PDF全文
Rita de Kássia Siqueira Teixeira Dayane Cristina Lima Ângela de Fátima Barbosa Abreu Magno Antonio Patto Ramalho 《Plant Breeding》2015,134(2):193-196
Brazilian consumers prefer beans of the beige grain colour. Common beans help supply dietary requirements for iron and zinc. The objectives of this study were (i) to determine whether early selection for grain colour affects the iron and zinc content and the grain yield in common beans and (ii) if an association between these characteristics was found, to obtain lines of carioca‐type grains with a high iron and zinc content and good grain yield. We evaluated 96 F3:4, F3:5 and F3:6 progeny at two locations for iron and zinc content and grain yield. We selected 48 progeny for grain colour and chose 48 others at random. We found that early selection for grain colour does not affect the zinc content and grain yield. A positive and high association was found between iron and zinc content, and both iron and zinc content were slightly negatively correlated with grain yield. It is possible to obtain common bean lines combining a high iron and zinc content with good grain yield as long as a selection index is used. 相似文献
73.
Ricardo Augusto Diniz Cabral Ferreira Magno Antonio Patto Ramalho Fernando Henrique Ribeiro Barrozo Toledo Angela de Fátima Barbosa Abreu 《Plant Breeding》2015,134(5):599-604
In the common bean crop in Brazil, the requirement of the value for cultivation and use trials is that these experiments must be conducted over two years in three locations per region. Information in regard to the necessary number of years to ensure precision in cultivar recommendation and the influence of evaluated years in the estimation of the GE interaction are still scarce. Using grain yield of five check varieties assessed over 11 years in three sowing seasons per year, the aims of this study are as follows: to measure the relative contribution of the GE interaction, evaluating the implication of the number of years in the estimates of the GE interaction, and infer how many years are needed to ensure precision in cultivar recommendation. For instances, analysis of variance was carried out involving all environments and also combinations of years. The results showed that the GE interaction was greater than all other cross‐effects involving lines. The use of at least two years allows good coincidence in cultivar recommendation compared to the whole period. Increasing the evaluation time is a good strategy, especially when it is difficult to grow three different sowing seasons. 相似文献
74.
Devesa V Loos A Súñer MA Vélez D Feria A Martínez A Montoro R Sanz Y 《Journal of agricultural and food chemistry》2005,53(26):10297-10305
A study of the transformation of arsenic species by the microflora of the freshwater crayfish Procambarus clarkii was carried out. The study of the degradation of AB (arsenobetaine) was performed in aerobic conditions in two culture media (tryptic soy broth and saline medium) at two temperatures (30 and 8 degrees C). The microflora transformed AB into TMAO (trimethylarsine oxide), DMA (dimethylarsinate), MA (methylarsonate), and an unidentified compound (U1). The quickest transformations were carried out by microflora from hepatopancreas incubated in saline medium at 30 degrees C. The individualized study of other arsenic species [AC (arsenocholine), TETRA (tetramethylarsonium ion), TMAO, DMA, and MA] was also performed in saline medium. The only transformation observed was of AC into AB. The bacteria possibly responsible for AB degradation were isolated, identified by phenotypic and genotypic methods, and individually assayed for AB transformation. Only isolates allocated to the species Pseudomonas putida were able to metabolize AB. 相似文献
75.
Remo Bucci Andrea D Magrí Antonio L Magrí Domenico Marini Federico Marini 《Journal of agricultural and food chemistry》2002,50(3):413-418
This work has focused on discriminating extra virgin olive oils from Sabina (Lazio, Italy) by olive fruit variety (cultivar). A set of oils from five of the most widespread cultivars (Carboncella, Frantoio, Leccino, Moraiolo, and Pendolino) in this geographical area was analyzed for chemical composition using only the Official Analytical Methods, recognized for the quality control and commercial classification of this product. The obtained data set was converted into a computer-compatible format, and principal component analysis (PCA) and a method based on the Fisher F ratio were used to reduce the number of variables without a significant loss of chemical information. Then, to differentiate these samples, two supervised chemometric procedures were applied to process the experimental data: linear discriminant analysis (LDA) and artificial neural network (ANN) using the back-propagation algorithm. It was found that both of these techniques were able to generalize and correctly predict all of the samples in the test set. However, these results were obtained using 10 variables for LDA and 6 (the major fatty acid percentages, determined by a single gas chromatogram) for ANN, which, in this case, appears to provide a better prediction ability and a simpler chemical analysis. Finally, it is pointed out that, to achieve the correct authentication of all samples, the selected training set must be representative of the whole data set. 相似文献
76.
77.
Fermin Rivera Gloria Vilaclara Alfonso Lugo Pedro Ramirez Esperanza Robles Antonio Labastida 《Water, air, and soil pollution》1988,37(1-2):1-12
Protozoological and physicochemical analyses were performed in a waste stabilization pond at Sto. Tomas Atzingo, a small town near Mexico City, in order to discern the internal dynamics of the pond water through the study of the spatial distribution pattern of flagellates and the parallel water volume distribution pattern of some selected physicochemical determined parameters. The statistical method applied to the data obtained was by cluster analysis. The results showed a slight trend to heterogeneity in the system, when it was evaluated through the physicochemically determined parameters. On the other hand, the spatial distribution pattern of the flagellates pointed out a remarkable heterogeneity in the pond. In systems like the one studied where the main feature is an organic matter overload, such a difference in findings indicates a low correlation between the biological parameters, in this case the flagellates, and the physicochemical variables, that should be considered when evaluating the water quality of such systems, either through the physicochemical, the biological or both scopes. 相似文献
78.
A heat-induced degradation was carried out over two crude paprika oleoresins diluted with high oleic or high linoleic oil. Occurrence of oxygen was avoided, and changes in individual carotenoids were followed over time. Degradation rate constants were not significantly different, so that carotenoid stability was not linked with unsaturation degree of the oily system. A parallel reaction to degradation, trans to cis carotenoid isomer conversion, was also denoted during the thermal treatment, and it initially showed a higher rate than degradation of cis-isomers. Both processes (isomerization and cis-isomers degradation) were finally compensated, and their development was also unaffected by the nature of the lipid profile. Under the reaction conditions, oleic and linoleic fatty acids showed the same reactivity and induced degradative reactions, equally affecting the carotenoid profile. An enhanced stability of carotenoid content and provitamin A value was not achieved with a decrease in the unsaturation level of the oily system. 相似文献
79.
Nino Tavares Amazonas Luiz Antonio MartinelliMarisa de Cássia Piccolo Ricardo Ribeiro Rodrigues 《Forest Ecology and Management》2011,262(8):1551-1557
We considered whether ecological restoration using high diversity of native tree species serves to restore nitrogen dynamics in the Brazilian Atlantic Forest. We measured δ15N and N content in green foliage and soil; vegetation N:P ratio; and soil N mineralization in a preserved natural forest and restored forests of ages 21 and 52 years. Green foliage δ15N values, N content, N:P ratio, inorganic N and net mineralization and nitrification rates were all higher, the older the forest. Our findings indicate that the recuperation of N cycling has not been achieved yet in the restored forests even after 52 years, but show that they are following a trajectory of development that is characterized by their N cycling intensity becoming similar to a natural mature forest of the same original forest formation. This study demonstrated that some young restored forests are more limited by N compared to mature natural forests. We document that the recuperation of N cycling in tropical forests can be achieved through ecological restoration actions. 相似文献
80.
A two-year study was carried out in the lower part of the Palmones River to describe the role of a small dam controlling the nutrient fluxes to the estuary. Results showed an important spatial heterogeneity in the nutrient content and water properties of lowland catchment due to the effects of the small dam and the effluents of a sewage treatment work. Taking into account the values of hydraulic retention time, the dam could be considered as an optimally dimensioned pre-dam. Therefore, it removed on average more than 25% of total phosphorus (TP) while no net removal was obtained for TN during the studied period. Palmones River exported 11.3 TonsP year?1 of TP and 72.1 TonsN year?1 of TN to the estuary showing important seasonal differences. Less than 10% from the total amount of nutrient was exported during low flow conditions, while in four months with important flooding events, the percentage of total nitrogen exported exceeded 64%. 相似文献