1,721,010 research outputs found
Tolerance of apricot to winter temperature fluctuation and spring frost in northern Italy
Patterns and heritability of carboxylic acids and soluble sugars in fruits of apricot (Prunus armeniaca L.)
The investigation of acid and sugar content in an array of apricot cultivars and progenies indicates the existence of marked variability. Citric acid varied from 0.17 to 1.20% and malic acid from 0.21 to 1.51% on fresh weight. Fructose varied from 0.27 to 1.60%, glucose from 0.90 to 3.13% and sucrose from 1.92 to 6.92%. The estimate of heritability was high for total and main sugars, reaching over 0.50%. Acids generally showed low coefficients, although those for citric (0.27) and malic (0.36) were good. With the exception of one progeny, all genotype/year comparisons were not significant, showing constant patterns for acid and sugars over the years regardless of the variability in absolute values. This means that the patterns of each genotype are under genetic control. The wide range of diversity in acid and sugar content apricot germplasm and the independent heritability for most of these compounds make it possible to breed and select cultivars with improved flavour on the basis of superior phenotypes
Going Beyond Counting First Authors in Author Co-citation Analysis
The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Bitterness inheritance in apricot (P. armeniaca L.) seeds
Seed bitterness, due to cyanogenic glucosides, has been reported in apricot as a recessive trait, being determined by a single gene. In this study, 21 F1 and 10 F2 populations from parents with either bitter or non-bitter ('sweet') phenotype were tested by seed tasting. Both the 'bitter' and the 'sweet' phenotypes were represented in populations from 'bitter x bitter' and 'sweet x sweet' crosses, as well as from self-pollination of either bitter- or sweet-seeded trees, providing evidence that more than one gene is involved in this trait. Ten populations showed segregation ratios inconsistent with a monofactorial inheritance of seed taste with the 'sweet' trait dominant over the 'bitter'. On the other hand, data from spectrophotometric assays indicate that seed cyanoglucoside content cannot be regarded as a quantitative trait. All the observed segregation ratios can be explained by an inheritance mechanism based on five, non-linked genes, involved in two distinct biochemical pathways. Three genes would control different steps in an 'additive' pathway (either the biosynthesis of cyanoglucosides, or their transport, or both) leading to accumulation of these metabolites in seeds: homozygosis of recessive alleles of at least one of them would result in the sweet phenotype. Two more genes would provide a cleaving activity, participating to cyanoglucoside catabolism; heterozygosis or homozygosis of dominant alleles at these loci would produce the 'sweet' phenotype, while homozygosis for recessive alleles of at least one of them would interrupt the catabolic pathway, leading to the 'bitter' trait, if associated with the anabolic function
Simultaneous determination of soluble sugars and organic acids as their trimethylsilyl derivatives in apricot fruits by gas-liquid chromatography
The aim of this study was to determine a reliable procedure for the quantification of organic acids, alcohol soluble sugars and sugar alcohols in fruit flesh by means of a rapid GLC method, without resorting to methoximation of sugars and employing apricot as a model. The use of two internal standards, an accurate derivatization and a proper calibration of the GLC conditions allowed an accurate quantitative analysis of the compounds detected in the unknown samples. This simple procedure improves the speed of preparation of the trimethylsilyl derivatives and is highly reproducible. Variability was found between years for each of the five cultivars studied and for each compound in terms of absolute values, whereas the percentage incidence of the single sugars as a total was more stable over the two years of observation
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