Using metabolic profiling to assess plant-pathogen interactions: an example using rice (<Emphasis Type="Italic">Oryza sativa)</Emphasis> and the blast pathogen <Emphasis Type="Italic">Magnaporthe grisea</Emphasis>

A metabolomics based approach has been used to study the infection of the Hwacheong rice cultivar (Oryza sativa L. cv. Hwacheong) with compatible (KJ201) and incompatible (KJ401) strains of the rice blast fungal pathogen Magnaporthe grisea. The metabolic response of the rice plants to each strain was assessed 0, 6, 12, 24, 36, and 48 h post inoculation. Nuclear Magnetic Resonance (NMR) spectroscopy and Gas and Liquid Chromatography Tandem Mass spectrometry (GC/LC-MS/MS) were used to study both aqueous and organic phase metabolites, collectively resulting in the identification of 93 compounds. Clear metabolic profiles were observed at each time point but there were no significant differences in the metabolic response elicited by each pathogen strain until 24 h post inoculation. The largest change was found to be in alanine, which was ~30% (±9%) higher in the leaves from the compatible, compared to the resistant, plants. Together with several other metabolites (malate, glutamine, proline, cinnamate and an unknown sugar) alanine exhibited a good correlation between time of fungal penetration into the leaf and the divergence of metabolite profiles in each interaction. The results indicate both that a wide range of metabolites can be identified in rice leaves and that metabolomics has potential for the study of biochemical changes in plant-pathogen interactions.     

Inbreeding and the inheritance of fertility in the thoroughbred mareLa consanguinité et l'hérédite de la fertilité chez la jument de pur sangInzucht und vererblichkeit der fruchtbarkeit bei voliblutstuten

The reproductive efficiency of the thoroughbred mare in Britain and Ireland is low Weatherby's General Stud Book shows an average annual foaling rate of 67%. The primary aim of this study was to measure the extent to which the poor foaling rate was attributable to inbreeding. Coefficients of inbreeding were calculated and lifetime reproductive histories were assembled for 6550 mares at stud in Britain and Ireland in the early 1960s. The average degree of inbreeding for the five most recent generations was found to be only 0.01, there was little variation among animals in amount of inbreeding, and the mating of sibs or parents and offspring was rare. Coefficients of total inbreeding were calculated for a group of 60 mares. For the 21.5 recorded generations from the foundation of the breed in the seventeenth century to 1964 the average degree of inbreeding was 0.125. There was considerable variation among estimates for different animals, but this was mainly attributable to sampling within pedigrees.Each mare's lifetime reproductive performance was summarised as the proportion of her successful years at stud, adjusted for the decline in fertility with age, scaled to have an average of 1.0, and transformed to stabilise variance. An analysis of variance of the resulting fertility measures was carried out. Recent inbreeding was not an important source of variation in fertility since the mating of close relatives was rare.Although lower fertility was associated with inbreeding, the effect was not statistically significant. The largest source of variation in fertility was the number of years at stud and there were significant differences among year of birth groups. In addition, there were significant differences among groups of paternal half sibs, and the heritability of fertility was estimated as 0.077 ± 0.030. Over the recorded history of the breed it is probable that selection, both natural and artificial, has counteracted any effect of inbreeding on fertility.     

甲酸乙酯对三种主要仓储害虫的熏蒸作用

为明确甲酸乙酯对仓储害虫的实际控制效果,避免二氧化碳对熏蒸作用的影响,该研究利用循环熏蒸系统(FTFS),测定甲酸乙酯对米象、赤拟谷盗、谷蠹三种主要仓储害虫混合虫态的熏蒸作用.结果表明:在25℃、70%RH条件下,甲酸乙酯43.34、80.72、99.08、117.74、146.49mg/L 熏蒸处理6 h,对赤拟谷盗和谷蠹混合虫态有很好的控制作用,死亡率大于95.96%;甲酸乙酯80.72、99.08、117.74、146.49mg/L处理对米象混合虫态的杀虫效果较好.甲酸乙酯对米象蛹的杀虫效果较差.     

溴甲烷对松木木质包装穿透性研究

25℃、48g/m3起始剂量条件下,溴甲烷熏蒸12h,熏蒸箱内溴甲烷浓度衰减率超过40%,而12h后到48h熏蒸结束时,溴甲烷衰减率小于5%。箱内溴甲烷CT值在6h达到200g.h/m3。溴甲烷对松木的穿透是顺着木纹进行的。在熏蒸48h内,无虫害木块内部各采样孔的溴甲烷浓度与箱内浓度无法达到平衡,15cm处CT值不足200g.h/m3;有虫害木块内部各采样孔溴甲烷浓度在20h与箱内浓度基本平衡,15cm处的溴甲烷CT值达到200g.h/m3需13h。     

Cavity and bark nesting bird response to partial cutting in Northern conifer forests

We investigated whether partial cutting used to mimic small-scale natural disturbances could maintain cavity and bark nesting breeding birds. We assessed changes in the relative abundance of cavity nesting birds in two intensities of partial cutting, compared to uncut and clearcut stands, 9 years post-treatment. We then examined the relationship between forest structure and nesting abundance (stand scale) and compared characteristics of used nest and forage trees to unused trees (tree scale). The relative abundance of most species was highest in either heavy removal or light removal treatments 9 years post-harvest. Brown creepers were most abundant in uncut, and red-breasted sapsuckers were most abundant in clearcut and heavy removal treatments. The proportion of deciduous trees and the density of dead trees were the best predictors of nest abundance. Individual nest tree use was predicted by the presence of large deciduous trees with broken tops and early to advanced stages of decay. Forage tree use was predicted by the presence of large conifer trees in advanced stages of decay. To maintain breeding habitat for cavity nesters, we suggest that forest managers retain the specific structural attributes required for nesting, but also the diverse forest conditions required for foraging.     

Statistical efficiency in bull progeny testing for calving difficulty

The binomial distribution was used to examine the precision attainable in bull progeny testing for traits like calving difficulty as the following parameters were varied: P_o, the basic incidence level in the population, n, the progeny group size, and α and β, the probabilities of two kinds of erroneous conclusion. The results showed that in all circumstances a group size of 250–300 progeny gave a good compromise between cost and precision.There was little to choose between testing based on calvings in heifers and in cows. As the basic frequency increases, more progeny are required for a given degree of precision. Thus testing is more expensive in breeds with high rates of difficult calving than in those with low rates.     

Post-fire survival and reproduction of rehabilitated and unburnt koalas

Fire can be a catastrophic event which causes high mortality and injury in wildlife. While rehabilitation of injured animals is common, no studies have measured the success of rehabilitated wildlife following fire. This study compared the long-term survival and reproduction of a group of injured, rehabilitated and released koalas (n=16) with that of uninjured koalas (n=23) following fires in fragmented forest in Port Stephens, Australia, in 1994. Individual koalas were monitored for up to three years following release. Survival rates were calculated using the Kaplan–Meier estimate, modified for the staggered-entry of new animals. There was no significant difference in the survival of rehabilitated and uninjured koalas after fire. Annual survival, derived by fitting an exponential decay function to the data, was estimated to be 58% for rehabilitated koalas and 67% for the uninjured koalas. Predation by dogs was the major cause of mortality for both groups. Reproduction did not differ significantly between the two groups over two breeding seasons following fire. It was concluded that rehabilitation of injured koalas was successful from the perspective of the individuals. Furthermore, such efforts have the potential to contribute to the recovery of populations depleted after fire and thus contribute to the long-term survival of koala populations.     

Settlement of Ostrea edulis is determined by the availability of hard substrata rather than by its nature: Implications for stock recovery and restoration of the European oyster

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