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ABSTRACT Rosewood, Aniba rosaeodora is an endangered species in Amazon forests and its natural stands have been heavily depleted due to over-exploitation for the cosmetic industry. This study aimed to investigate the genetic diversity and population structure of 90 rosewood accessions from eight localities in the Peruvian Amazon through 11 Inter Simple Sequence Repeats (ISSR) primers. The ISSR primers produced a sum of 378 bands, of which 375 (99.2%) were polymorphic, with an average polymorphism information content (PIC) value of 0.774. The mean effective number of alleles (Ne), Shannon informative index (I), gene diversity (He) and total gene diversity (Ht) were 1.485, 0.294, 0.453 and 0.252, respectively. Analysis of molecular variance (AMOVA) showed the presence of maximum variability within populations (88%). The Structure algorithm, neighbor joining and principal coordinate analysis (PCoA) grouped the 90 rosewood accessions into three main populations (A, B and C). Diversity indices at the inter-population level revealed a greater genetic diversity in population A, due to higher gene flow. The neighbor-joining analysis grouped populations A and B, while population C was found to be divergent at the inter population level. We concluded that population A reflects higher genetic diversity and should be prioritized for future management and conservation plans.

Peach (Prunus persica (L.) Batsch) is one of the most produced and studied stone fruits. Many genetic and genomic resources are available for this species, including a high-quality genome. More recently, a new high-density Illumina peach Single Nucleotide Polymorphism (SNP) chip (9+9K) has been developed by an international consortium as an add-on to the previous 9K array. In the current study, this new array was used to study the genetic diversity and population structure of the National Peach Germplasm Collection of the Agrifood Research and Technology Centre of Aragon (CITA), located in Zaragoza (northern Spain). To accomplish this, 90 peach accessions were genotyped using the new peach SNP chip (9+9K). A total of 9796 SNPs were finally selected for genetic analyses. Through Identity-By-Descent (IBD) estimate analysis, 15 different groups with genetically identical individuals were identified. The genetic diversity and population structure elucidated a possible exchange of germplasm material among regions, mainly in the northern regions of Spain. This study will allow for more efficient management of the National Peach Germplasm Collection by classifying valuable individuals for genetic diversity preservation and will benefit forthcoming Genome-Wide Association Studies (GWAS) of commercially important fruit traits in peach.

Copyright of Ecosistemas y Recursos Agropecuarios is the property of Universidad Juarez Autonoma de Tabasco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de la Sociedad Química del Perú is the property of Sociedad Quimica del Peru and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This work describes, for the first time, the changes taking place in the antioxidative system of the leaf apoplast in response to plum pox virus (PPV) in different Prunus species showing different susceptibilities to PPV. The presence of p-hydroxymercuribenzoic acid (pHMB)-sensitive ascorbate peroxidase (APX) (class I APX) and pHMB-insensitive APX (class III APX), superoxide dismutase (SOD), peroxidase (POX), NADH-POX, and polyphenoloxidase (PPO) was described in the apoplast from both peach and apricot leaves. PPV infection produced different changes in the antioxidant system of the leaf apoplast from the Prunus species, depending on their susceptibility to the virus. In leaves of the very susceptible peach cultivar GF305, PPV brought about an increase in class I APX, POX, NADH-POX, and PPO activities. In the susceptible apricot cultivar Real Fino, PPV infection produced a decrease in apoplastic POX and SOD activities, whereas a strong increase in PPO was observed. However, in the resistant apricot cultivar Stark Early Orange, a rise in class I APX as well as a strong increase in POX and SOD activities was noticed in the apoplastic compartment. Long-term PPV infection produced an oxidative stress in the apoplastic space from apricot and peach plants, as observed by the increase in H2O2 contents in this compartment. However, this increase was much higher in the PPV-susceptible plants than in the resistant apricot cultivar. Only in the PPV-susceptible apricot and peach plants was the increase in apoplastic H2O2 levels accompanied by an increase in electrolyte leakage. No changes in the electrolyte leakage were observed in the PPV-inoculated resistant apricot leaves, although a 42% increase in the apoplastic H2O2 levels was produced. Two-dimensional electrophoresis analyses revealed that the majority of the polypeptides in the apoplastic fluid had isoelectric points in the range of pI 4–6. The identification of proteins using MALDI-TOF (matrix-assisted laser desorption/ionization-time of flight) and peptide mass fingerprinting analyses showed the induction of a thaumatin-like protein as well as the decrease of mandelonitrile lyase in peach apoplast due to PPV infection. However, most of the selected polypeptides showed no homology with known proteins. This fact emphasizes that, at least in Prunus, most of the functions of the apoplastic space remain unknown. It is concluded that long-term PPV infection produced an oxidative stress in the leaf apoplast, contributing to the deleterious effects produced by PPV infection in leaves of inoculated, susceptible Prunus plants. [ABSTRACT FROM PUBLISHER]

Abstract: The resistance/susceptibility level of 213 descendants from three different crosses between the French apricot cultivar ‘Polonais’ (susceptible to Plum pox virus, sharka), and the North American cultivar ‘Stark Early Orange’ (resistant) was evaluated during four cycles of study under controlled greenhouse conditions. Resistant:susceptible ratios were 83:17 in the case of the ‘Stark Early Orange’ open-pollination descendants, 62:38 in ‘Polonais’בStark Early Orange’ descendants, and 28:72 in ‘Polonais’בPolonais’. These ratios were checked against the expected ratios of different genetic control hypotheses, combining one, two or three genes involved in the expression of this trait and with the resistance being a dominant (Hypothesis A) or recessive trait (Hypothesis B). In addition, two other, more complex hypotheses were proposed: that the resistance is controlled by 2 independent genes, the resistance being recessive for one and dominant for the other (Hypothesis C), and another hypothesis considering the resistance to be controlled by one dominant gene and admitting a 25% error in the evaluation process (Hypothesis D). The χ 2-test was applied to compare the goodness-of-fit of the proposed hypotheses. Hypothesis D seems to be the most consistent in the three apricot crosses studied. [Copyright &y& Elsevier]

Abstract: Correlations between 29 quantitative tree and fruit traits were studied in 46 almond genotypes and some inter-specific crosses. Results reflected a significant diversity in the assayed almond germplasm. In addition, the obtained cluster demonstrated varying degrees of relationships, illustrating higher correlation values for the flowering traits and lower correlation values for the nut and kernel traits. To determine the importance of the traits and the levels of similarity existing between the various studied traits, a discriminate analysis was carried out. According to the results obtained from these analyses, the different traits were discriminated on basis of the characteristics of the presence of double kernels, the nut and the kernel size, the flowering date, kernel yield and shelling percentage. Finally, this study evidenced correlations between most of the agronomic traits in almond, although the correlations coefficient (r) value was found to be higher than 0.5 only in some cases. This analysis can help breeders for choosing the most favorable entries to build a core subset of the almond collection for the purpose of breeding. [Copyright &y& Elsevier]

Abstract: In this study we compare the evaluation of Plum pox virus (Sharka) resistance of 29 apricot genotypes in controlled greenhouse conditions by grafting onto infected ‘GF305’ peach seedlings growing in pots, and in natural conditions by grafting onto infected 5-year-old apricot trees growing in the orchard. Apricot genotypes evaluated were initially classified into three groups: susceptible to PPV (presence of PPV symptoms and ELISA positive in greenhouse and field assays), resistant (absence of PPV symptoms and ELISA negative in both assays) and undetermined (evaluated differently in both assays). Results showed a similar behavior against Plum pox virus in both assays in 20 out of the 29 apricot genotypes studied (69%). However, in the other nine genotypes results were different (31%). Evaluation in field was more accurate, detecting a higher number of susceptible genotypes, probably due to the higher inoculation pressure in the old trees in comparison with the GF305 rootstocks in pots. However, greenhouse evaluation let to work in controlled isolated conditions with a higher number of genotypes. This situation is greatly required in areas where Sharka is not widely spread. Greenhouse evaluation could be then the first screening method to evaluate Plum pox virus resistance of apricot genotypes, and could be complemented with the evaluation onto infected trees in natural conditions in insect-proof quarantine shelter. [Copyright &y& Elsevier]

Abstract: In this work we have performed a comparative study of the utilization of three electrophoresis separation methods for the analysis of peach SSR polymorphism in almond and its implications in the assessment of genetic diversity and relatedness. Automated SSR detection and polyacrylamide gel electrophoresis were the most efficient methods and would be able to resolve allelic variation at a finer scale than the electrophoresis in MetaPhor® agarose. Moreover, automated electrophoresis detection is much more expensive in terms of cost of equipment and cost of the analysis. In addition, SSR detection using polyacrylamide gel electrophoresis showed similar results than automated sequencing, although it is more time-consuming and toxic than electrophoresis in agarose gels. Discrepancies among polyacrylamide and automated capillary, and MetaPhor® were observed when differences in SSR polymorphisms were between 1 and 5bp. While the use of MetaPhor® agarose appears less indicated for genotype characterization, this technique may be the most convenient in other applications, i.e. mapping of population, due to its lower cost and easier routine application. The utilization MetaPhor® agarose produced a slightly different clustering of genotypes in spite of the big differences observed in the DNA fingerprinting. However, bootstrap values using MetaPhor® agarose were lower indicating a lower accuracy of this SSR polymorphism analysis method. [Copyright &y& Elsevier]