Flavan-3-ols and procyanidins in grape seeds: biodiversity and relationships among wild and cultivated vines

Flavan-3-ol monomers and polymers composition of seeds from wild (17) and autochthonous (8) Vitis vinifera grapes growing in northern Tunisia were evaluated. Wild grape seeds were spherical with a small beak and relatively a high seed/berry ratio (~ 18.1%w/w). Local cultivars developed pyriform-shaped seeds with a well-developed beak representing on average 2.2% of total weight of the berry. Flavanol concentrations ranged between 40.9 and 67.5 mg/g FW in seeds from wild accessions and between 48.9 and 96.7 mg/g FW in seeds from cultivated grapes. Differences between accessions were highly significant (p < 0.01) and seeds from cultivar ‘Boukhasla’ showed the highest polyphenols content. Among flavan-3-ol monomers, (+)-catechin was predominant for all ecotypes and generally their abundance was: (+)-catechin (Cat) > (?)-epicatechin (Ec) > (?)-epicatechin-3-O-gallate (EcG). The Cat/Ec ratio was approximately 1.7 for wild grapes while it was about 2.5 for cultivated grapes. Procyanidins in wild seeds differed from cultivated ones by a lower mDP and higher proportions of galloylated derivatives, likely to affect fruit bitterness and astringency. (?)-epicatechin was the main extension subunit in grape seed procyanidins, reaching on average 52% in wild and 58% in cultivated seeds. Hierarchical cluster analysis based on seeds morphometry and procyanidin profile indicated close proximity between some wild and cultivated grapes suggesting that some cultivars derived from ancestral events of local domestication or cross hybridization with native wild plants.     

Natural Stable Isotopes for Determination of Gastrointestinal Transit Time in Fish

This study evaluated the application of stable isotopes of carbon as an alternative and more accurate method to determine gastrointestinal transit time (GTT) in fish by comparing it to the inert marker method. The stable isotope method detects alterations of the normal carbon flow in a biological system by analyzing naturally occurring isotopes of carbon, contrary to studies based on conventional techniques that apply external markers to the diet to determine GTT through visual observation of the color change in feces. Therefore, 320 pacu, Piaractus mesopotamicus juveniles were reared in 32 tanks under two different temperatures (25 and 29 C). The pacu juveniles received two different diets, one based on ingredients derived from C₃ photosynthetic cycle plants and the other based on C₄ plant ingredients, both containing titanium oxide (TiO₂) as a marker. After 40 d, the isotopic signature of the diets was changed, and the marker was replaced by chromic oxide (Cr₂O₃). In the isotopic technique, the feces were analyzed to determine the exchange in the isotopic ratio of carbon δ¹³C. Both methods found that GTT was faster (nearly 6 h) in fish at 29 C when using the C₄/C₃ feeding strategy and slower in fish at 25 C using the C₃/C₄ strategy (15 h by inert marker and 18 h by the isotopic method). In conclusion, GTT determination in pacu juveniles using the stable isotope technique exhibits the same accuracy obtained with the inert marker method at temperatures suitable (nearly 29 C) for the metabolism of these animals.     

Ultrastructural Morphology and Nuclear Maturation Rates of Immature Equine Oocytes Vitrified with Different Solutions and Exposure Times

Ultrastructural morphological injuries and maturation rates were investigated in equine oocytes exposed to vitrification solutions (VS) containing synthetic ice blockers (SIBs) during different exposure times. In experiment 1, compact cumulus-oocyte complexes (COCs; n = 30) were randomly allocated to treatments: (1) fresh fixed (control); (2) VS-1 (1.4 M dimethyl sulfoxide [DMSO] + 1.8 M ethylene glycol [EG] + 1% SIB) for 3 minutes of equilibrium time and VS-2 (2.8 M DMSO + 3.6 M EG + 0.6 M sucrose + 1% SIB) for 1 minute (Eq-long); and (3) VS-1 for 1.5 minutes and VS-2 for 30 seconds (Eq-short). In experiment 2, compact (n = 248) and expanded (n = 264) COCs were evenly distributed to the following treatments: (1) immediate maturation in vitro (control); (2) vitrification using the Eq-short protocol as in experiment 1; and (3) vitrification using a stock solution containing 2.8 M formamide, 2.8 M DMSO, 2.7 M EG, 7% polyvinylpyrrolidone, and 1% SIB (Eq-short-mod). More (P < .02) oocytes with normal ultrastructural morphology were seen in fresh control and Eq-short groups than in Eq-long group. Metaphase-II (MII) rates were higher (P < .05) for oocytes with expanded cumulus than compact cumulus in the control group, and higher (P < .05) for oocytes with expanded cumulus than compact cumulus in Eq-short and Eq-short-mod groups. No difference in MII rates was detected among groups within each type of COC. In conclusion, reduction of exposure time to VS better preserved oocyte ultrastructural features, and MII rates were higher for vitrified oocytes with expanded cumulus. This study advances our knowledge on potential alternatives for vitrification of immature equine oocytes.     

Effect of soil drying on mucilage exudation and its water repellency: a new method to collect mucilage

Despite the importance of mucilage for soil–plant relations, little is known about the effect of soil drying on mucilage exudation. We introduce a method to collect mucilage from maize growing in wet and dry soils. Mucilage was collected from brace roots. The amount of mucilage exuded did not change with soil water content and transpiration rate. Mucilage exuded in dry soils had a higher degree of hydrophobicity, suggesting that the wetting properties of mucilage change in response to soil drying.     

Television viewing behaviour and associations with food habits in different countries

OBJECTIVE: Several environmental factors influence adolescents' food habits and television (TV) viewing is thought to be one of these factors. The purpose of the present study was to describe sociodemographic differences in TV viewing and to examine associations of TV viewing with the consumption of sweets, soft drinks, fruit and vegetables in different countries. METHODS: Data were collected from 162,305 young people completing the 2001/02 Health Behaviour in School-Aged Children survey, a World Health Organization cross-national study on health and health behaviours among 11-, 13- and 15-year-old school pupils. Analyses of variance were used to examine sociodemographic differences in TV viewing and logistic regression analyses to examine associations between TV viewing and food habits. RESULTS: Large differences were found between countries in reported daily TV viewing time, from an average of 2.0 h in Switzerland to 3.7 h in Ukraine. The results indicate that those most likely to watch TV are boys, 13-year-olds and pupils of lower socio-economic status. Those who watched more TV were more likely to consume sweets and soft drinks on a daily basis and less likely to consume fruit and vegetables daily, although the latter associations were not so apparent among Central and Eastern European countries. CONCLUSIONS: Given the high TV viewing rates among adolescents and the association with less healthy food options, many young people are at increased risk of overweight or obesity. Interventions to modify TV viewing behaviour are needed. The findings underscore the importance of tackling socio-economic differences.     

Production of DAPG and HCN by Pseudomonas sp. LBUM300 contributes to the biological control of bacterial canker of tomato

Bacterial canker caused by Clavibacter michiganensis subsp. michiganensis is known to cause significant economic losses to tomato production worldwide. Biological control has been proposed as an alternative to current chemical containment methods, which are often inefficient and may leave adverse effects on the environment. However, only little headway has so far been made in developing biocontrol strategies against C. michiganensis subsp. michiganensis. To address this knowledge gap, we investigated the antagonistic capacity of PCA, produced by Pseudomonas sp. LBUM223, and DAPG and HCN, both produced by Pseudomonas sp. LBUM300, on C. michiganensis subsp. michiganensis under in vitro and in planta conditions. Nonsynthesizing isogenic mutants of the producer strains were also developed to further dissect the role of each individual metabolite on C. michiganensis subsp. michiganensis biological control. Novel specific quantitative polymerase chain reaction TaqMan assays allowed quantification of C. michiganensis subsp. michiganensis in tomato plants and rhizospheric soil. Pseudomonas spp. LBUM223 and LBUM300 significantly repressed C. michiganensis subsp. michiganensis growth in vitro, while their respective nonproducing mutants showed less or no significant antagonistic activity. In planta, only Pseudomonas sp. LBUM300 was capable of significantly reducing disease development and C. michiganensis subsp. michiganensis rhizospheric population, suggesting that the production of both DAPG and HCN was involved. In summary, simultaneous DAPG/HCN production by Pseudomonas sp. LBUM300 shows great potential for controlling bacterial canker of tomato.     

Molecular marker-based genetic linkage map of a diploid banana population (Musa acuminata Colla)

A well-saturated genetic linkage map is valuable for fundamental and applied genetic research. Genetic linkage maps of two half-sib diploid banana populations were constructed using allele-specific-polymerase chain reactions (AS-PCRs), diversity array technology (DArT), and simple sequence repeat (SSR) markers. Molecular maps were produced for each parent using the pseudo-testcross mapping strategy. The first maternal map (6142-1, 81 individuals) consisted of 231 markers divided as followed: 121 DArT, 106 SSR and 4 AS-PCR markers in 15 linkage groups (LGs) covering 670?cM. The second maternal map (6142-1-S, 58 individuals) contained a total of 152 markers including 71 DArTs, 79 SSRs, and 2 AS-PCRs mapped to 16 LGs that spanned 698?cM. The combined paternal map (139 individuals) comprised 316 markers (196 DArTs, 117 SSRs and 3 AS-PCRs) distributed over 15 LGs with a total map length of 1,004?cM. While distorted segregation of some markers was observed in all maps, this was much more frequent for the male parent. Homology between maps was assessed using common markers. While there was generally good congruity with regard to marker order across maps, incongruity in other cases may reflect chromosomal rearrangement events such as inversions, translocations, or deletions. The new banana map can provide a better understanding of the Musa genome and could be used for the identification of economically important traits and improvement of breeding strategies.