蓝舌病灭活疫苗免疫羊ELISA和琼扩监测比较试验

用19只绵羊（注苗前BTV琼扩和ELISA均为阴性）注射BTV灭活苗后7～139天的血清进行BTVELISA和琼扩平行试验，结果表明，注苗后7～30天11只试验丰ELISA阳性，注苗40天13只羊ELISA阳性，注苗90天以后全部试验羊只均为ELISA阳性，而琼扩试验则始终为阴性结果。     

食品安全校内实习基地建设与管理探索与实践

食品安全校内实习基地是学生进行食品安全实习活动的重要场所。该文介绍食品安全校内实习基地建设的重点,提出实习基地管理的措施。     

A contribution to the systematics of a piedmontese plum ecotype

Prunus domestica L., P. insititia L., P. salicina Lindl. and P. cerasifera Ehrh. are the most important species included in the plum group. Many ‘cultivars’ have an undefined origin and share very similar morpho‐phenological characteristics that make their identification difficult. This is the case of ‘Ramasin’, a group of Piedmontese genotypes whose fruits are small, ellipsoidal and very tasty. They are commonly considered as P. domestica varieties, even though on the basis of some morphological characteristics they are similar to other species such as P. insititia. In order to study the origin of this group, the DNA of 25 genotypes of ‘Ramasin’, and that of some ‘cultivars’ of P. domestica, P. insititia, P. cerasifera, P. salicina and two selections of P. spinosa L. was examined. The PCR‐RAPDs method (Random Amplified Polymorphic DNA amplified by Polymerase Chain Reaction) was used and all 69 primers that were tested generated more or less polymorphic bands. From the results of these analyses it can be supposed that the ‘Ramasin’ plums are a single genetically heterogeneous group. Moreover it can probably be assumed that ‘Ramasin’ arose from crosses between P. domestica and P. insititia.     

特优559产量构成因素及丰产稳产性分析

应用数理统计方法对特优559产量构成因(?)及丰产稳产性进行了分析,结果表明:特优559丰产性、稳产性好,适应性强。产量构成因素中以穗数与产量的关系最为密切,对产量的作用最大,其次是每穗总粒数,再次是结实率,千粒重对产量的作用不大。揭示其高产途径和主攻目标是“攻足穗,争大穗,提高结实率,稳定粒重”,使穗、粒、重协调发展,夺取高产。     

Interactions between rodents and weeds in a lowland rice agro‐ecosystem: the need for an integrated approach to management

Rodents and weeds are important pests to rice crops in Southeast Asia. The interaction between these 2 major pests is poorly documented. In temperate cereal systems, seeds of grass weeds can be an important food source for rodents and weed cover along crop margins provides important refuge for rodents. In 2012 and 2013, a replicated study (n = 4) in Bago, Myanmar compared 4 treatments (rodents and weeds; no rodents and weeds; rodents and no weeds; no rodents and no weeds) each of 0.25 ha in transplanted rice. Weeds were managed with hand weeding in the wet season, and hand weeding and herbicides in the dry season. Plastic fences were installed to exclude rodents. We examined the weed cover and relative abundance of weed species, rodent damage, rodent population dynamics and rice yield loss caused by rodents and weeds. The dominant rodent species was Bandicota bengalensis. In the dry season, Cyperus difformis was dominant at the tillering stage and Echinochloa crus‐galli was the dominant weed species at the booting stage. In the wet season E. crus‐galli was a dominant weed throughout the season. Damage by rodents was higher in the dry season. There were larger economic benefits for best weed management and effective rodent control in the dry season (258 US$/ha) than in the wet season (30 US$/ha). Concurrent control of weeds in and around rice fields combined with coordinated community trapping of rodents during the early tillering stage and ripening stage of rice are recommended management options.     

Trial grow‐out culture of sea cucumber Holothuria scabra in sea cages and pens

Field trials were conducted to determine the effects of size, grow‐out period and site on the growth and survival of Holothuria scabra. Juveniles were reared in sea cages in two sites for 2 months during two different times of the year. Juveniles from Experiment 1 were subsequently grown in sea pens for 8 months in one site. The significantly lower survival particularly of the small‐sized group (<0.1 g) in Pilar is likely due to reduced water and sediment quality because of proximity to fish‐farming activities. The importance of grow‐out period was evident in the significant differences in weight increments in all size groups and biomass in the small‐sized group (P < 0.10) in Lucero during Experiment 2 when water temperature range and incidence of rainfall were higher. The decrease in the average weight of adults during the second half of the grow‐out period may be due to the interplay of the reduction in salinity, onset of sexual maturity and biomass exceeding carrying capacity in the pens. The estimated biomass threshold in the sea cages and pens in Lucero were 300 g m^?2 and 380 g m^?2 respectively. Implications of the results on the viability of small‐scale pen grow‐out culture are discussed.     

Removal of short‐range‐order minerals prior to grain‐size analysis of volcanic ash soils

Incomplete dispersion of aggregates is a well‐known difficulty when analyzing soil texture of Andosols, particularly if no fresh soil material is available. To facilitate such investigations, several dispersion procedures were carried out on air‐dried samples rich in short‐range‐order minerals, originating from selected Andosol profiles (S Mexico). As a result, we propose an improved method based on a sequential chemical treatment with K oxalate, NH₄ oxalate, and oxalic acid that reliably removes cementing agents and allows for a stable dispersion of soil particles after addition of Na pyrophosphate. This method was proved to be well reproducible and highly reliable for routine grain‐size determinations. The potential error caused by the inherent risk of dissolving primary minerals or fresh volcanic glass remains far beyond the analytical error resulting from the incomplete and irreproducible dispersion of highly resistant aggregates by other commonly used techniques.     

不同遮光率对香水花扦插苗生长的影响

本文探讨了4种不同遮光率对香水花(Heliotropium arborescens)扦插苗生长的影响,结果表明不同光照条件对香水花植株在新增株高、萎焉发生、植株分枝、开花和生长量等方面有着十分重要的影响,在4个处理中,处理3遮光70%处理植株的生长状况最好,处理4遮光90%处理属于遮光过度,造成植株徒长,处理2遮光50%处理属于遮光不够,而处理1全光照处理很容易造成植株发生萎焉情况。