The drug transporter MgMfs1 can modulate sensitivity of field strains of the fungal wheat pathogen Mycosphaerella graminicola to the strobilurin fungicide trifloxystrobin

BACKGROUND: The major facilitator superfamily (MFS) drug transporter MgMfs1 of the wheat pathogen Mycosphaerella graminicola (Fuckel) J Schroeter is a potent multidrug transporter with high capacity to transport strobilurin fungicides in vitro. The data presented in this paper indicate that, in addition to the predominant cause of strobilurin resistance, cytochrome b G143A subsititution, MgMfs1 can play a role in sensitivity of field strains of this pathogen to trifloxystrobin. RESULTS: In a major part of field strains of M. graminicola (collected in the Netherlands in 2004) containing the cytochrome b G143A substitution, the basal level of expression of MgMfs1 was elevated as compared with sensitive strains lacking the G143A substitution. Induction of MgMfs1 expression in wild-type isolates upon treatment with trifloxystrobin at sublethal concentrations proceeded rapidly. Furthermore, in disease control experiments on wheat seedlings, disruption mutants of MgMfs1 displayed an increased sensitivity to trifloxystrobin. CONCLUSION: It is concluded that the drug transporter MgMfs1 is a determinant of strobilurin sensitivity of field strains of M. graminicola.     

Identifying high yielding stable winter wheat genotypes for irrigated environments in Central and West Asia

Improved winter wheat (Triticum aestivum L.) cultivars are needed for the diverse environments in Central and West Asia to improve rural livelihoods. This study was conducted to determine the performance of elite winter wheat breeding lines developed by the International Winter Wheat Improvement Program (IWWIP), to analyze their stability across diverse environments, and to identify superior genotypes that could be valuable for winter wheat improvement or varietal release. One hundred and one advanced winter wheat breeding lines and four check cultivars were tested over a 5-year period (2004–2008). Grain yield and agronomic traits were analyzed. Stability and genotypic superiority for grain yield were determined using genotype and genotype × environment (GGE) biplot analysis. The experimental genotypes showed high levels of grain yield in each year, with mean values ranging from 3.9 to 6.7 t ha⁻¹. A set of 25 experimental genotypes was identified. These were either equal or superior to the best check based on their high mean yield and stability across environments as assessed by the GGE biplot analysis. The more stable high yielding genotypes were ID800994.W/Falke, Agri/Nac//Attila, ID800994W/Vee//F900K/3/Pony/Opata, AU//YT542/N10B/3/II8260/4/JI/Hys/5/Yunnat Esskiy/6/KS82W409/Spn and F130-L-1-12/MV12. The superior genotypes also had acceptable maturity, plant height and 1,000-kernel weight. Among the superior lines, Agri/Nac//Attila and Shark/F4105W2.1 have already been proposed for release in Kyrgyzstan and Georgia, respectively. The findings provide information on wide adaptation of the internationally important winter wheat genotypes, and demonstrate that the IWWIP program is enriching the germplasm base in the region with superior winter wheat genotypes to the benefit of national and international winter wheat improvement programs.     

Retrieval of forest structural parameters using LiDAR remote sensing

In this paper, a literature overview is presented on the use of laser rangefinder techniques for the retrieval of forest inventory parameters and structural characteristics. The existing techniques are ordered with respect to their scale of application (i.e. spaceborne, airborne, and terrestrial laser scanning) and a discussion is provided on the efficiency, precision, and accuracy with which the retrieval of structural parameters at the respective scales has been attained. The paper further elaborates on the potential of LiDAR (Light Detection and Ranging) data to be fused with other types of remote sensing data and it concludes with recommendations for future research and potential gains in the application of LiDAR for the characterization of forests.     

The potential for rhizobial inoculation to increase soybean grain yields on acid soils in Ethiopia

In Ethiopia, inoculation of soybean with rhizobial inoculants is not common practice, but could provide an option to increase grain yields in low nitrogen (N) acidic soils. In these acid soils, the selection of acid tolerant rhizobia is one strategy that may increase the performance of soybean. In this study, rhizobial strains isolated from Ethiopian soils were evaluated for their acid tolerance and symbiotic N fixation efficiency with soybean, in controlled environments. Following this, four isolated rhizobial strains were evaluated in six field experiments in major soybean growing areas of Ethiopia. Inoculation with the commercial strain or with one of two locally sourced isolates, that were developed as inoculants, improved soybean yield. The yield increase due to inoculation with the commercial strain was consistent and greater than other treatments, while the increase due to the two locally sourced strains was comparable to, or greater than, application of 46 kg N/ha in soils, where the resident rhizobial population was ≤1.4 × 10³ cfu/g soil. For soils with high background rhizobial populations, there was no response to inoculation. In one of the experimental sites (Bako), the percentage of N fixed (%Ndfa) was 55 for the commercial strain and 35 for the local strain, ES3. This study demonstrated that field validation is a necessary step in the selection of acid-tolerant strains of rhizobia to increase soybean production for Ethiopia.     

Paired Somite Counts to Assess the Within-litter Diversity in Embryonic Development at Day 17, 19 and 21 of Pregnancy in Meishan and Yorkshire × Landrace Crossbred Gilts

Contents Eight Meishan and nine Large White × Landrace Crossbred gilts, 7 to 8 months of age, were slaughtered at 17, 19 or 21 days after insemination to determine the within-litter diversity in embryonic development as measured by the number of paired somites as well as by the length and weight of embryos after fixation. Embryonic survival was similar for the two breeds, averaging 85.1 ± 8.5% and 82.8 ± 9.4% for Meishan and Crossbred, respectively. No degenerating embryos were recovered. The normal Meishan and Crossbred embryos were developed similarly at each of the three stages of pregnancy (p ≥ 0.05). The within-litter diversity (s. d.) in the number of somites per embryo was not related to the average number of somites per embryo per litter, nor was it different between breeds. However, the within-litter diversity (s. d.) in the length and weight of embryos increased with increasing average length and weight per embryo per litter, respectively. The increase tended (p < 0.10) to be larger in the Meishan litters. It was concluded that the number of paired somites, the length and the weight of embryos on Days 17, 19 and 21 of pregnancy, give essentially the same information concerning the development of embryos. However, the number of paired somites provides additional information concerning the change in within-litter diversity in embryonic development with increasing average litter development. Inhalt: Unterschiede in der Emryonalentwicklung am 17., 19. und 21. Trächtigkeitstag bei Meishansauen und Yorkshire × Landrasse Kreuzungstieren, gemessen anhand der Anzahl gepaarter Somiten. Jungsauen (acht Meishan- und neun Large White × Landrasse-Kreuzungstiere) im Alter zwischen sieben und acht Monaten wurdem am Tag 17, 19 und 21 nach Besamung geschlachtet, um anhand der Zahl gepaarter Somiten, der Embryolänge und dem Gewicht festzustellen, wie groß die Variation der Embryonalentwicklung innerhalb eines Wurfes ist. Die embryonale Überlebensrate war für beide Rassen (Meishan und Kreuzungsrasse) gleich (im Mittel 85,1 ± 8,5 % und 82,8 ± 9,4%). Degenerierte Embryonen wurden nicht gewonnen. An den Untersuchungstagen entsprachen sie dem erwarteten Entwicklungs-stand (p ≥ 0.05). Die Unterschiede innerhalb des Wurfes (s.d.) hinsichtlich der Somiten-zahlwar nicht mit der durchschnittlichen Somitenzahl pro Embryo pro Wurf korreliert, noch gab es Rasseunterschiede. Bezüglich Größe und Gewicht wurde dagegen eine Zunahme der Variabilität innerhalb des Wurfes bei durchschnittlichem Anstieg dieser beiden Parameter beobachtet. Bei Meishanschweinen schien dies tendenziell deutlicherzu sein (p < 0.10). Daraus läßt sich folgern, daß grundsätzlich ähnliche Aussagen aus det Somitenzahl wie aus Länge und Gewicht der Embryonen am Tag 17, 19, und 21, bestehen. Die Somitenzahl erbringt darüber hinaus noch zusätzliche Znformationen bezüglich der Unterschiede innerhalb des Wurfes.     

Biochemical Mechanisms Involved in Selective Fungitoxicity of Two Sterol 14α-Demethylation Inhibitors,Prochloraz and Quinconazole: Accumulation and Metabolism Studies

The selective fungitoxic actions of prochloraz (an imidazole) and a triazole fungicide, quinconazole (3-(2,4-dichlorophenyl)-2-(1 H- 1,2,4-triazol-1-yl)- 4(3H)-quinazolinone: II ), were studied with selected phytopathogenic fungi. With the exception of Ustilago maydis, all the fungi tested were more sensitive to prochloraz than to II. A number of DMI-resistant mutants of Penicillium digitatum and P. italicum showed positive cross-resistance to both DMIs, but except for P. italicum isolate H17, the levels of resistance to II were much higher than to prochloraz. The generally higher toxicity of prochloraz to the fungi investigated, as compared to II , could not be ascribed to the slightly higher accumulation of prochloraz. With regard to prochloraz, there was no general correlation between the sensitivity of the fungi tested and the amount of fungicide accumulated. A similar situation was evident for II. However, the DMI-resistant mutants of P. italicum did show a reduced accumulation of both azoles, which may account for a low level of acquired DMI-resistance in this fungus. Since accumulation levels of the test compounds in the isolates with different degrees of resistance were the same, additional mechanisms of resistance may be involved in isolates with relatively high degrees of DMI-resistance. No detectable amounts of fungicide metabolites were found in most fungi tested over a 16-hour incubation period. Therefore, fungal metabolism is not generally responsible for the differences in sensitivity between fungi to each azole tested. It also does not generally explain the differential toxicities of prochloraz and II to each individual species. The exception to this was Rhizoctonia solani which metabolized prochloraz to a non-fungitoxic compound. This correlated with its low prochloraz sensitivity.     

Interference of the phenylpyrrole fungicide fenpiclonil with membranes and membrane function

The phenylpyrrole fungicide fenpiclonil accumulates to high levels in mycelium of Fusarium sulphureum and artificial liposomes. The accumulation is a result of a physicochemical distribution of the fungicide over lipid-like material of the mycelium and the medium. Accumulation is reversible, as the fungicide can easily be removed from the mycelium by washing with water. Fenpiclonil is not metabolized by the fungus during incubation for 24 h. The fungicide affects neither membrane fluidity in artificial liposomes nor amino acid accumulation in bacterial vesicles. Thus, accumulation of the fungicide does not seem to affect the functioning of membranes. Fenpiclonil induces the accumulation of the membrane-potential probe tetra-phenylphosphonium bromide by F. sulphureum. Since accumulation of this probe probably reflects the cumulative potential over all cell membranes, the increased accumulation is more likely a result of changes of potentials over membranes of intracellular organelles rather than plasma membrane hyperpolarization. Hence, the previously described effects of fenpiclonil on amino acid and saccharide uptake cannot be explained by plasma membrane hyperpolarization.     

Effect of early training on the jumping technique of horses

OBJECTIVE: To investigate the effects of early training for jumping by comparing the jumping technique of horses that had received early training with that of horses raised conventionally. ANIMALS: 40 Dutch Warmblood horses. PROCEDURE: The horses were analyzed kinematically during free jumping at 6 months of age. Subsequently, they were allocated into a control group that was raised conventionally and an experimental group that received 30 months of early training starting at 6 months of age. At 4 years of age, after a period of rest in pasture and a short period of training with a rider, both groups were analyzed kinematically during free jumping. Subsequently, both groups started a 1-year intensive training for jumping, and at 5 years of age, they were again analyzed kinematically during free jumping. In addition, the horses competed in a puissance competition to test maximal performance. RESULTS: Whereas there were no differences in jumping technique between experimental and control horses at 6 months of age, at 4 years, the experimental horses jumped in a more effective manner than the control horses; they raised their center of gravity less yet cleared more fences successfully than the control horses. However, at 5 years of age, these differences were not detected. Furthermore, the experimental horses did not perform better than the control horses in the puissance competition. CONCLUSIONS AND CLINICAL RELEVANCE: Specific training for jumping of horses at an early age is unnecessary because the effects on jumping technique and jumping capacity are not permanent.