Accumulation of SBI fungicides in wild-type and fenarimol-resistant isolates of Penicillium italicum

Fenarimol-resistant laboratory isolates of Penicillium italicum exhibit a high degree of cross-resistance to triazoles, a low degree of cross-resistance to imazalil and a low degree of negatively-correlated cross-resistance to morpholines. The cross-resistance to triazoles is ascribed to a differential accumulation level of these SBI fungicides in wild-type and fenarimol-resistant isolates. As in the case of fenarimol, the relatively low accumulation level of triazoles in resistant isolates is probably caused by the operation of a constitutive, energy-dependent efflux from mycelium, which hinders the triazoles from reaching their site of action in sterol biosynthesis. The accumulation level of imazalil and morpholines did not differ among wild-type and fenarimol-resistant isolates. This may be related to the fact that these fungicides at physiological pHs occur in a protonated form. The lack of a differential accumulation level can be the reason for the deviating cross-resistance patterns of these fungicides.     

原生质体融合技术改良植病生防木霉菌株

以产孢量大，对苯菌灵有抗性，对潮霉素B敏感的哈茨木霉菌株T9和产孢量少，对潮霉素B有抗性，对苯菌灵敏感的康宁木霉菌株Tk7a为亲本，进行原生质体融合，筛选获得抗最高浓度杀菌剂的融合子。所有融合子的产孢量均比亲本菌株Tk7a大。融合子按照菌落形态的不同分成4组，大部分融合子的几丁质酶、葡聚糖酶和内切葡聚糖酶的活性比亲本菌株高。融合子对棉花猝倒病菌和小麦全蚀病菌的寄生能力基本等同于亲本菌株；融合子对小麦全蚀病的防效比亲本菌株稍好，其刺激麦苗根部生长的能力与亲本菌株相差不大。两个融合子根际竞争能力比亲本菌株T9强，和亲本菌株Tk7a相当。     

黄瓜苗期猝倒病生物防治

通过盆栽和田间小区试验,研究了生防菌对黄瓜苗期猝倒病的防治效果。盆栽试验中,生防菌株CR56对甲霜灵高抗病原菌株Pythium ultimum ONCURO1和敏感菌株P.spinosum MP43419的防效分别为94.4％和51.4％;生防菌CUC8对两者防效分别为0.0％和61.9％;在供试的19株生防细菌中,有11株格兰氏阴性菌对ONCURO1的防效好于对MP43419,有5株格兰氏阳性菌对MP43419防效则好于对ONCURO1。田间小区试验中,生防菌株PEP66在浙大菜圃和弄口菜地对黄瓜苗期猝倒病的防效分别为35.8％和18.5％,但R2在两地的防效分别为14.3％和84.4％。供试的11株生防菌中,有10株在弄口菜地对黄瓜苗期猝倒病的防效优于在浙大菜圃。结果显示出生防菌的防效与供试土壤中病原种类和种群数量有密切的关系。     

Can jumping capacity of adult show jumping horses be predicted on the basis of submaximal free jumps at foal age? A longitudinal study

The purpose of this study was to quantify performance characteristics of good jumping horses, and to determine whether these were already detectable at foal age. Kinematic data were collected of horses performing free jumps over a 0.60 m high fence at six months of age and of these same horses jumping with a rider over a 1.15 m high fence at five years of age. At five years of age the horses were divided into three groups on the basis of a puissance competition: a group of seven best jumpers that made no errors and in the end cleared a 1.50 m high fence, a group of nine worst jumpers that were unable to clear a 1.40 m high fence, and an intermediate group of 13 horses. Longitudinal kinematic data was available for all seven best jumpers and for six of the nine worst jumpers. Average values of variables for the best jumpers were compared with those of the worst jumpers for the jumps over 1.15 m. In the group of best jumpers, the forelimbs were shorter at forelimb clearance due to increased elbow flexion, and the hind limbs were further retroflexed at hind limb clearance. The same superior technique in clearing fences with the limbs was also found in this group at six months of age. Nevertheless, for individual horses it turned out to be too far-fetched to predict adult jumping capacity on the basis of kinematic variables collected during submaximal jumps at foal age.     

Biomass expansion factors for Sitka spruce (<Emphasis Type="Italic">Picea sitchensis</Emphasis> (Bong.) Carr.) in Ireland

The assessment of a forest resource in national inventories provides a firm basis for the calculation of biomass and carbon (C) stocks of forests. Biomass expansion factors (BEFs) and conversion factors provide a robust and simple method of converting from forest tree stem volume to total forest biomass. These factors should be constructed on the basis of nationally specific data in order to take account of regional differences in growth rates, management practices, etc. The objective of this study is to improve the accuracy of biomass estimation by calculating a range of age-dependant BEFs from representative data that more accurately describe the allometry of present forests. The results from this study show that the allocation of biomass to compartments in forest stands and throughout a rotation varies considerably, and that the use of BEFs for the calculation of C stocks in forests of sub-timber dimensions is highly impractical.

Impact of fungal drug transporters on fungicide sensitivity, multidrug resistance and virulence

Drug transporters are membrane proteins that provide protection for organisms against natural toxic products and fungicides. In plant pathogens, drug transporters function in baseline sensitivity to fungicides, multidrug resistance (MDR) and virulence on host plants. This paper describes drug transporters of the filamentous fungi Aspergillus nidulans (Eidam) Winter, Botrytis cinerea Pers and Mycosphaerella graminicola (Fückel) Schroter that function in fungicide sensitivity and resistance. The fungi possess ATP-binding cassette (ABC) drug transporters that mediate MDR to fungicides in laboratory mutants. Similar mutants are not pronounced in field resistance to most classes of fungicide but may play a role in resistance to azoles. MDR may also explain historical cases of resistance to aromatic hydrocarbon fungicides and dodine. In clinical situations, MDR development in Candida albicans (Robin) Berkhout mediated by ABC transporters in patients suffering from candidiasis is common after prolonged treatment with azoles. Factors that can explain this striking difference between agricultural and clinical situations are discussed. Attention is also paid to the risk of MDR development in plant pathogens in the future. Finally, the paper describes the impact of fungal drug transporters on drug discovery.     

Minimally Invasive Surgical Pastern Arthrodesis: An Ex Vivo Study Comparing Three Different Drilling Techniques for Cartilage Destruction

The objective was to compare the degree of cartilage destruction obtained with three different drilling techniques for minimally invasive arthrodesis of the equine pastern joint. Three drilling techniques were randomly tested on 36 cadaver distal limbs (six front and six hind limbs in each group). The basic drilling pattern consisted of several passes in a dorsopalmar and/or plantar direction across the joint space (group 1) and was either supplemented with one additional pass in a lateromedial and/or mediolateral direction (group 2) or two additional passes in a distodorsal–proximopalmar and/or plantar direction (group 3). After drilling, the pastern joints were disarticulated, the articular surfaces of P1 and P2 were digitally photographed, and the area of removed cartilage was measured using planimetry. The mean percentage of cartilage removed in the entire pastern joint was significantly lower in group 1 (34.1 ± 4.0%) compared with groups 2 and 3 (45.0 ± 5.2% and 43.0 ± 4.0%, respectively; P < .001). There was significantly more cartilage removed in the hind (47.1 ± 4.4%) versus the forelimbs (42.0 ± 5.0%) of group 2 (P = .003), whereas in group 3, there was significantly more cartilage removed in the forelimbs (44.6 ± 3.0%) compared with the hind limbs (40.6 ± 3.0%) (P = .039). The technique of group 2 gave significantly more cartilage destruction compared with technique 1 while being practical to perform. Therefore, this technique seems to be the most promising for further evaluation in a clinical situation.