BIOECONOMICS OF COBIA,RACHYCENTRON CANADUM,CULTURE IN VIETNAM

This article presents an analysis of the profitability and intensity of cobia culture by small-scale farmers in Vietnam, especially focusing on current feeding practices and perceptions regarding adoption of manufactured diets. Bioeconomic modelling is used so the interactions between biological and economic processes can be analyzed. Overall, it is found that cobia farming is moderately to highly profitable when compared to other aquaculture species in Vietnam. Culture practices and the level of intensity of cobia farming differ significantly across Vietnam. Initial stocking density, total number of fish stocked, number and size of cages, and quantity of feed used are all higher in southern Vietnam than the north. The higher level of intensification in the south leads to significantly higher total costs, productivity and profitability. The dominant cost source is feed, which is predominantly low-value fish. To capture the environmental and potential economic benefits of adopting pelleted diets, then negative farmer perceptions regarding relatively slow growth rates, and lack of availability compared with low-value fish need to be overcome.     

基于SRAP标记的土沉香遗传多样性分析

【目的】在我国野生土沉香被大量被采伐,种质资源越来越少,甚至面临消失的情况下,为了利用与保护野生土沉香提供理论依据,采用SRAP分子标记对其种源遗传多样性进行分析。【方法】基于我国11个土沉香种源群体和越南2个土沉香种源群体的SRAP结果,应用POPGEN32软件对遗传多样性参数进行计算。【结果】各群体Nei's基因多样度指数的变化范围为0.1715~0.5394,Shannon多样性指数的变化范围为0.2491~0.4837,多态位点百分比的变化范围为42.03%~76.81%。运用GenAlex 6.4软件对土沉香13个群体进行分子方差分析(Analysis of molecular variance,AMOVA),结果显示有30%的遗传变异来自土沉香群体间,70%的遗传变异来自土沉香群体内。【结论】13个土沉香种源有中度的遗传多样性和遗传分化,野生土沉香种质资源正日渐稀少,应该加强资源的保护与利用。     

Stabilization of toxic metals in three contaminated soils by residual impact of lime integrated with biochar and clays

Journal of Soils and Sediments - Mine and smelter soil contaminations with Pb, Cu, Cd, and Zn have become serious problems in China, because of anthropogenic activities. Little is known about the...     

杂交粳稻亲本米质性状优异配合力的标记基因型鉴定

杂交粳稻米质整体水平不如常规粳稻也是限制杂交粳稻广泛种植的原因之一。本研究选用115个SSR引物扩增6个粳稻BT型不育系和12个恢复系的标记基因型,并分析72个F₁组合谷粒长、谷粒宽、糙米率、精米率、整精米率、垩白米率、垩白度、糊化温度、胶稠度和直链淀粉含量10个米质性状的配合力,结合亲本SSR分子标记数据和性状配合力数据筛选了10个米质性状优异配合力的标记基因型。结果共鉴定出30个SSR标记基因型与亲本10个米质性状配合力显著相关,其中25个与亲本米质性状不良配合力相关,5个与优异配合力相关。标记基因型RM263-175/180和RM444-230/240可以使F₁整精米率分别提高3.2%和2.5%。RM3-120/150可以使F₁谷粒长缩短2.4%,RM444-180/240可以使F₁谷粒宽增加2.1%。RM428-273/294可以使F₁植株上的杂交稻米直链淀粉含量减少7.0%。有8个标记基因型同时也影响产量性状配合力。RM3-120/150同时可以使F₁的每穗总粒数和每穗实粒数分别增加15.9%和10.9%。RM1211-150/160可使F₁的糙米率和精米率分别减少0.9%和1.1%,同时使F₁的每穗总粒数和每穗实粒数分别增加21.8.%和20.4%。RM23-150/160可使F₁的垩白米粒率和垩白度分别增加44.1%和45.7%,同时使F₁的单株日产量和每穗总粒数分别增加11.2%和11.6%。这些结果可用于指导亲本米质性状和产量性状配合力的分子标记辅助改良以及未来杂交粳稻组合配置中的亲本选配。     

Trace Metal Contamination During Grinding of Plant Samples

Inductively coupled plasma-mass spectroscopic (ICP-MS) analysis of leaves from 22 cabbage crops in the Sa P? and B?c Hà districts of Láo Cai Province, North-Western Vi?t Nam, revealed unexpectedly high concentrations of chromium (Cr) and nickel (Ni). The concentrations were strongly linearly related (r² = 0.94), indicating sample contamination during grinding through a stainless-steel hammer mill. We tested this hypothesis in two ways. First, brown rice ground through the same mill was contaminated not only by Cr and Ni, but also cobalt (Co), iron (Fe) and molybdenum (Mo). Second, scanning electron microscopy/energy dispersive analysis of x-rays (SEM/EDS) of the ground samples revealed small fragments with co-located Fe, Cr and Ni, consistent with stainless steel wear fragments. Other grinders may perform differently and we suggest that quality assurance protocols for trace metal analysis of plants should include testing for grinder wear metals. Lastly, brown rice appears to be convenient for investigating contamination of plant tissues during grinding.     

杂交粳稻亲本产量性状优异配合力的标记基因型筛选

提高杂交粳稻竞争优势的关键是改良其恢复系产量性状的配合力。为使之更富成效,选用115个SSR引物扩增6个粳稻BT型不育系和12个恢复系的标记基因型,并按NCII遗传设计配制72个F1组合,分析18个亲本的单株日产量、单株有效穗数、每穗总粒数、每穗实粒数、千粒重5个性状的配合力,结合亲本SSR分子标记数据和性状配合力数据筛选了5个性状优异配合力的标记基因型。结果发现20个SSR标记基因型与亲本产量及其构成性状配合力显著相关。其中8个与亲本单个性状配合力相关;6个同时与亲本2个性状配合力相关;4个同时与亲本3个性状配合力相关;2个同时与亲本4个性状配合力相关。同时与多个性状配合力相关的标记基因型,对各性状的作用方向有正有负。RM152-165/170是单株日产量和单株有效穗数优异配合力效应最大的标记基因型,可使F1的相应性状值增加20.6%和12.7%。优异配合力的标记基因型可直接用于粳稻恢复系配合力的分子标记辅助改良。     

培养基和植物生长调节剂对青钱柳悬浮细胞三萜产量的影响

探讨培养基种类和植物生长调节剂配比对青钱柳悬浮细胞生长、总三萜和三萜单体含量及产量的影响。结果表明：MS＋1．0 mg／L NAA＋0．5 mg／L KT最适合青钱柳悬浮细胞生长,最终产量达到12．03 g／L;WPM＋0．5 mg／L 2,4－D ＋0．3 mg／L NAA显著提高了青钱柳悬浮细胞中总三萜的含量;青钱柳悬浮细胞中均能检出阿江榄仁酸、青钱柳酸B、齐墩果酸和熊果酸的存在,且阿江榄仁酸和青钱柳酸B含量较高,但基本培养基种类和不同植物生长调节剂组合对悬浮细胞中4种三萜单体含量无显著影响。青钱柳悬浮细胞中总三萜产量以MS＋0．5 mg／L 2,4－D＋0．3 mg／L NAA处理最高,而三萜单体产量均以MS＋1．0 mg／L NAA＋0．5 mg／L KT处理最高。     

Salinity intrusion and rice production in Red River Delta under changing climate conditions

This study was carried out to identify the vulnerability of rice production to salinity intrusion arising from climate change in Giao Thuy, a coastal district of Nam Dinh Province, located in Red River Delta in Vietnam. From the analysis of historical climate data at Nam Dinh city, both mean maximum and minimum temperatures increased by about 0.3 and 0.1 °C per decade, respectively, during the period of 1961–2010. Salt concentration of the river water was higher at the irrigation gate closer to river mouth (Con Nhat) than at the upstream gate (Ha Mieu), which generally increased from 2003 to 2012, with the average maximum concentration up to 2.13 % at Con Nhat gate in 2010. The salt water concentration in the riverside field outside the dyke reached 3.6 %, while among the fields within dyke the salinity was only 0.7 % at maximum in January 2013, and the values were higher in paddy fields close to the dyke than far from the dyke. Average yield among the selected 27 fields from 2011 summer to 2013 spring rice was higher in spring rice (748 g m^?2) but lower in summer rice (417 g m^?2) mainly due to unfavorable weather such as cold spell at flowering and flood at harvesting time. Rice yield was lowest in general in the most downstream commune Giao Thien, and was significantly lower in field located close to the dyke than those far from the dyke. This spatial variability of rice yield may not be directly attributable to salinity, but to the other factors such as shift of irrigation intake gate to further upstream and/or different management such as less input of N fertilizer and use of traditional local variety.     

In vitro primary porcine alveolar macrophage cell toxicity and African swine fever virus inactivation using five commercially supply compound disinfectants under various condition

Efficacy of African swine fever virus (ASFV) inactivation using five commercially supply compound disinfectants was evaluated under various condition. Virucidal efficacy demonstrated that products A and E could inactivate at 1:800 within 1 min for both temperatures, while products B, C and D inactivated at 1:400. However, product D could inactivate at 1:800 when the exposure time was extended to 30 min and effected only 20°C. In addition, the cytotoxicity demonstrated that products A, B, C, D and E did not significantly affect to cell at 1:51,200, 1:12,800, 1:12,800, 1:25,600 and 1:12,800 dilution, respectively. In conclusion, these disinfectants could inactivate ASFV, however, the application of these products should be performed under safety precautions to prevent cytotoxicity in humans and animals.     

A long-term observation for ecology of pathogenic Yersinia in wild rodents living in Fukushima Prefecture,Japan

From 2012 to 2021, prevalence of pathogenic Yersinia in wild rodents captured in Fukushima Prefecture, Japan was investigated twice a year to clarify the ecology of this pathogen in wild rodent populations. Pathogenic Yersinia enterocolitica O8 was isolated from 13 (1.7%) of 755 wild rodents. The Y. enterocolitica O8 isolates harbored three virulent genes (ail, fyuA, and virF). This pathogen was isolated repeatedly from wild rodents in April 2015, 2016, and 2017, in June and November 2020, and in April 2021, which was 6 of 19 times of observations. All Y. enterocolitica O8 isolates showed the same PFGE patterns. These results indicated that the same clone of pathogenic Y. enterocolitica O8 has been maintained in wild rodent populations in Fukushima Prefecture. Therefore, wild rodent populations contribute substantially to the continuous transmission of Y. enterocolitica O8 and its persistence in the ecosystem. This is the first report on the isolation of pathogenic Y. enterocolitica O8 in wild rodents in Fukushima Prefecture, Japan.