Field evidence for apparent competition mediated via the shared parasites of two gamebird species

Although apparent competition mediated via shared parasites is potentially an important force influencing community structure, there is limited evidence to demonstrate its occurrence in the field. Here we show that the intensity of infection by the caecal nematode Heterakis gallinarum picked up by naive grey partridges, both maintained in pens and released on six gamebird estates in the UK, is significantly correlated with the intensity of infection recorded in the previous year from pheasants on those estates. Furthermore, the worm burdens picked up appeared to be sufficient to negatively influence host condition. These results provide evidence that infection from pheasants determines the worm burdens of partridges in the field, supporting the hypothesis that parasite-mediated apparent competition with the pheasant may be a factor influencing the decline and subsequent recovery of wild grey partridges.     

Infection Process of Botrytis cinerea on Eucalypt Leaves

This study aimed to elucidate the infection process of Botrytis cinerea on eucalypt leaves. Tests were conducted to evaluate the influence of leaf side (adaxial or abaxial), leaf age and luminosity on conidial germination, appressorium formation and grey mould (GM) severity. The adaxial and abaxial surfaces of detached eucalypt leaves were inoculated with a conidial suspension of B. cinerea and kept under constant light or dark. Subsequently, the adaxial surface of young and old leaves was inoculated and kept in the dark. To evaluate the percentage of conidia germination and appressorium formation, leaf samples were collected 6 hours after inoculation (hai), clarified (alcohol and chloral hydrate) and evaluated under a light microscope. The severity of GM was assessed 10 days after inoculation. For scanning electron microscopy analysis, samples were collected from 2 to 168 hai. A higher percentage of conidia germination (92%) and GM severity (21%) occurred on the adaxial surfaces of leaves kept in the dark. There was no statistical difference between the surfaces of young and old leaves for conidia germination. No appressorium was formed by B. cinerea. The GM severity on young leaves (17.3%) was 34 times higher than on old leaves (0.5%). The micrographs showed germinating conidia emitting 1–4 germ tubes in samples at 4 hai. The fungus penetration occurred through intact leaf surfaces, and both extra‐ and intracellular colonization of the mesophyll cells by the hyphae of the pathogen were observed at 120 hai. Sporulation occurred on the adaxial and abaxial surfaces (macronematous conidiophores) and below the epidermis (micronematous conidiophores).     

玉米优异地方种质资源的筛选与评价

本文对20个玉米优异地方品种资源主要农艺性状进行了研究,运用灰色系统理论的方法,分析了资源的综合性状及各性状间的关系。研究结果表明,株高影响穗粗,穗位高影响穗长,株高和穗位均低的资源不会有较高的单株粒重;叶片数对资源的筛选、利用有一定的影响,对穗长、穗粗、单株粒重有显著影响;利用生育期较短的资源可能会选出单株粒重较高的自交系和杂交种。据此结果结合育种目标评价,筛选出白头霜、高油玉米、洛阳85、白鹤、二夏、品综2号、本地黄玉米、金皇后8个玉米地方品种,综合农艺性状好,具有较高的利用价值。     

Can energy policies affect the cycle of carbon emissions? Case study on the energy consumption of industrial terminals in Shanghai,Jiangsu and Zhejiang

This paper proposes an approach to calculate the time series of cumulative carbon dioxide (CO₂) emissions between 1995 and 2014 based on industrial energy consumption data in three Eastern China jurisdictions in Shanghai, Jiangsu and Zhejiang during these two decades. Using the Hodrick-Prescott filter, the fluctuation components of the cumulative CO₂-emission time-series data in the three provinces are obtained. Subsequently, a grey correlation-based change-point search algorithm is used to determine change-points in these data. Additionally, the CO₂-emission time-series is divided into stages based on the change-points. The cycle characteristics of national energy policies, laws, and regulations are compared with those of the cumulative CO₂-emission cycle of the three provinces to analyse the impact of energy policies on CO₂ emissions. This study shows that, although the industrial structure and trends in the CO₂ emission time-series data of the three provinces are different, their cumulative CO₂-emission cycle remains the same from 1995 to 2014. The variation characteristics of the cumulative CO₂ emissions for each cycle during this period are well aligned with the stage characteristics of energy policies, laws, and regulations, indicating that energy policies play a consistent role in regulating such emissions. This study examines low-carbon production and sustainable energy development, and offers suggestions for issuing and perfecting energy policies, laws, and regulations, considering the indicators of energy consumption and CO₂ emissions.     

Hypertonicity-induced phosphorylation of proteins in Dictyostelium discoideum

Abstract By exposing the cells of Dictyostelium discoideum to a high concentration (120 mM) of KCl, several species of proteins (188 kilodalton (kDa), 95 kDa, and 71 kDa) are specifically phosphory-lated. This phosphorylation is induced irrespective of the time of starvation of cells by KCl, but not by cAMP, and inhibited by cycloheximide. The ³²P-labeled phosphoryl groups of 95- and 71-kDa proteins disappear by chasing during the subsequent differentiation step in a liquid shake culture. The majority of the 188- and 95-kDa proteins exist in the plasma membrane fraction.     

Colonization ability as an indicator of enhanced biocontrol capacity—An example using two Bacillus amyloliquefaciens strains and Botrytis cinerea infection of tomatoes

An understanding of biocontrol activities is important when developing microorganism‐based alternatives to conventional fungicides. From our bacterial collection, we selected two strains (BBC023 and BBC047) for their outstanding antagonistic capacity against fungal phytopathogens and growth‐promoting abilities towards Arabidopsis thaliana. According to physiological and molecular characterizations, both strains were classified as Bacillus amyloliquefaciens and were tested against Botrytis cinerea in vitro and in a tomato. Both strains secrete lipopeptide‐like compounds that contribute to their in vitro antagonism. SEM‐images showed altered B. cinerea mycelial structures that were consistent with previous reports of the direct action of lipopeptides against fungal hyphae. The strains were applied to the roots (R), leaves (foliar ‐ F) or root/leaves (R/F) on tomato plants. All treatments significantly reduced the severity of B. cinerea infection (measured as a control index). However, only root applications (R and R/F) led to growth promotion in the tomato plants. We detected the production of indole acetic acid (IAA) and 2,3‐butanediol as growth promotion traits in the two strains. For both strains, the R/F treatment showed the highest control index, suggesting a synergic effect of direct antagonism against B. cinerea and resistance induction in the plant. In addition, in vitro antagonism of BBC023 and BBC047 against B. cinerea was similar; whereas in the F application, strain BBC047 significantly improved plant resistance and maintained a higher population density over time on tomato leaves, compared to BBC023. BBC047 was also able to produce a complex and robust biofilm in Msgg medium compared with that of BBC023. We linked the reduced biocontrol of BBC023 on leaves with its limited ability to generate robust biofilms and colonize the phylloplane. At last, we highlight the potential of the native Bacillus strains as promising alternatives for the development of bioproducts for sustainable agriculture.     

黑龙江下城子组类三角蚌的复合模化石及其形态和沉积学意义

复合模化石是贝壳被溶蚀后,由于早期成岩压缩作用的影响,原贝壳的内模和外模互相叠加压印而成的化石,其正、负模上均印有原壳的内面和外表的特征。这种石具有形态和沉积学意义。     

Why does slug length correlate with speed during migration inDictyostelium discoideum?

Taking advantage of the fact that static electricity in plastic Petri dishes will produce very long, thin migrating slugs ofDictyostelium discoideum, it was shown that these slugs moved particularly rapidly. This is consistent with the demonstration of Inouye and Takeuchi that speed varies with length for slugs migrating on agar. Based on these observations it is suggested that slug speed is controlled by both the resistance at the tip and some factor that correlates With slug size, such as the concentration of endogenously produced ammonia