海南口岸从巴新进境柿属木材中截获天牛新种——嘉氏萎鞘天牛

海南口岸从巴布亚新几内亚进境柿属(Diospyros sp.)木材中截获一种天牛,经鉴定为天牛新种——嘉氏萎鞘天牛(Epania gressitti Huang,ChenCai,2014)。本文对该种的形态特征进行了重描述,增加雄性生殖器的形态描述,并编制近似种检索表,供检疫鉴定时参考。     

Antispasmodic effect of 4'-methylepigallocatechin on guinea pig ileum

The antispasmodic effect of 4'-methylepigallocatechin (MEC), which was isolated from Maytenus rigida Mart (Celestraceae), was investigated in vitro in guinea pig intestinal segments. In the isolated ileum, MEC (1 nM-100μM) did not modify the ileal spontaneous tonus or the electrically elicited contractions. MEC (8μM) significantly (p<0.01) reduced the submaximal contractions induced by histamine (2μM), carbachol (100μM) and BaCl(2) (0.03M). An additive relaxing action (p<0.001) was observed by co-incubation of verapamil (10 nM) and MEC (8μM). Although MEC (1nM-100μM) did not modify the contractions elicited by 60mM KCl, it significantly reduced the CaCl(2) contractile response without changing the EC(50) (effective concentration of CaCl(2) causing 50% of maximum response). In brief, these results show that MEC has a potent ileal spasmolytic effect and blocks spasms induced by specific and nonspecific stimuli. Importantly, the spasmolytic effects were attained at low concentrations and might be related to the symptomatic relief of abdominal pain that is obtained from the use of the M. rigida stem bark.     

Expert Opinion to Identify High‐Risk Entry Routes of Canine Rabies into Papua New Guinea

The proximity of Papua New Guinea (PNG) to canine rabies‐endemic countries in South‐East Asia presents a risk of incursion of this disease into PNG and the rest of the Oceanic region. The objective of this study was to identify the highest risk routes for entry of dogs – associated with movement of people – into PNG from canine rabies‐endemic countries. A structured, in‐country expert‐elicitation workshop was used, and 20 entry routes were identified. The highest risk routes were three land routes from Papua, Indonesia (hunters, traditional border crossers and unregulated, unchecked ‘shopper‐crossers’) and two sea routes (fishing and logging). These results will be used to direct more detailed risk assessments to develop surveillance strategies and incursion response plans.     

Diachronic (1979–2003) analysis of rice genetic diversity in Guinea did not reveal genetic erosion

Greater insight into the dynamics of genetic resources of crop plants is needed in order to pinpoint detrimental evolutionary patterns and draw up conservation priorities. Temporal evolution of rice genetic diversity was monitored in Maritime Guinea where subsistence-oriented agriculture prevails. Diachronic comparison was performed between samples collected in six villages during the 1979/1982-period and in 2003, based on the names and number of varieties inventoried and the polymorphism of microsatellite markers. The number of varieties appeared not to be comparable between the two dates, due to differences in the collection methods. The varietal composition had evolved very substantially between the two collection dates. Many long-duration varieties present in 1979/1982 had been abandoned and several improved varieties had been introduced. The mean number of alleles per locus and per accession was significantly higher in accessions collected in 2003. Pairwise comparisons of the mean number of alleles per locus in 1979/1982–2003 homonymous accession pairs indicated higher intra-accession diversity for the 2003 collections. Genetic differentiation, measured with the F _ST values, was very high and significant for more than 80% of these pairs of accessions. The overall genetic differentiation between accessions from the two collections dates was also significant. Significant changes were also observed for allelic composition. However, alleles specific of each collection date had much lower frequency, compared to alleles common to the two collection dates. These results suggest that rice genetic diversity in Maritime Guinea has been maintained or even enhanced. Old collections of crop genetic resources are often not exhaustive enough to undertake perfect diachronic comparison. New methods to utilize this historical data for diversity monitoring are needed.     

On size and growth in freshwater fish

Patterns of growth and size achieved in freshwater fish are examined with relation to the issues of indeterminate and determinate growth and asymptotic growth. Various authors suggest minimum, average and maximum sizes attained by fish, variously pointing to very small gobies and very large sharks, with most fish being about 150 mm long. Growth in fish is distinctive in that typically it continues throughout life, even though it becomes slower with increasing age and the onset of sexual maturity. Growth rates and size achieved by fish are highly flexible and subject to both genetic and environmental controls, so that size reached may vary with environmental variables such as water temperatures and food availability (both food abundance and prey types and sizes). Frequency distributions of 5 disparate freshwater fish faunas (Papua-New Guinea 267 species and tropical; North America 709 species and subtropical to Arctic; Australia 176 species and tropical to temperate; New Zealand and Great Britain 27 and 39 species and both warm to cool temperate) closely resemble distributions generated by the theoretical model of Hutchinson & MacArthur, and also data on diverse faunas. Frequency distributions in these faunas are closely similar, with a majority of species being small. This similarity would seem to suggest a general explanation. However, examination of the freshwater fish fauna of North America suggests that, rather than showing a predominance of large fish in the Arctic, the fauna has more large fish towards the tropics, though the proportion of large fish there is lower owing to the proliferation of small species in the tropics and a paucity of them towards the Arctic. Analysis shows a shift in the size composition of the fauna with latitude and shows that the general pattern for the whole of North America consists of a composite series of rather different patterns. This suggests that there is probably no meaningful general explanation of the overall patterns seen in these diverse and disparate faunas and that the similarity in overall size distributions between freshwater fish faunas of North America, New Guinea, Australia and New Zealand are of little ecological or evolutionary significance. The generality of Cope's rule is questionable, especially for fish, in which dwarfing and/or evolution towards smaller size are seen to be common phenomena.     

代用基质对新几内亚凤仙生长发育的影响

研究了代用基质对新几内亚凤仙根系及植株生长的影响。数据显示,所选代用基质基本都能创造一个适宜的根际环境,不会影响根系的生长。植株形态指标均优于泥炭基质或无显著差异,生物量的积累也呈现出类似的规律。但是根系活力、酶活性及可溶性蛋白测定数据显示,新几内亚凤仙对玉米芯粉基质生长适应性差;且由模糊数学分析结果显示,玉米芯粉基质栽培条件下植株形态综合指数低于泥炭基质,表现出一定的不适应性。其他代用基质栽培条件下,植株生长势普遍高于泥炭基质,在生产中完全有可能全部或部分地替代泥炭。     

Food,coffee and casuarina: an agroforestry system from the Papua New Guinea highlands

An agroforestry farming system is described from the Papua New Guina highlands (1400 to 2100 m) that has been developed by village growers since about 1960 and has expanded rapidly since about 1970. Major components of the system are numerous species of annual and perennial food crops (especially bananas), arabica coffee andCasuarina oligodon. It provides food, a cash crop and timber for construction and fuel. It is likely that returns on labour inputs are very favourable, but no formal assessments have been made. Evaluation of the system as a whole, and research on certain key components (casuarina ecology, banana cultivars, timing of operations) are suggested as high priority areas for systematic studies.     

A preliminary investigation into agroforestry practices in the savanna belt of western Nigeria

This paper evaluates agroforestry practices in a part of the Guinea savanna belt of south-western Nigeria. The attitude of local farmers to tree planting in crop fields was evaluated. Tree adoption on the farm was assessed by identifying the tree species on the field and their frequencies. The results show that there is little indication that the trees are deliberately utilized to enhance farm operations in the area. It is concluded that greater attention needs to be given to the promotion of agroforestry techniques in the savanna belt. This is especially important as the increasing demand for food would put pressure on the soil resources.     

几内亚高原地区温度对水稻结实和粒重的效应

在几内亚国立波尔多农业实验站观察了水稻抽穗后30天当地温度对水稻结实和粒重的影响。表明在西非高原日最低温度10°C可作为影响水稻空粒率的极限温度,日最低温度和日温差的大小对水稻结实期间的灌浆与粒重无不良影响。