湖南省长沙市羊布鲁氏菌病基线调查

为了解湖南省长沙市布鲁氏菌病流行现状,对奶羊养殖场(户)和种羊场采用普查策略,对其他羊养殖场(户)采用两阶抽样策略,选择羊群并选定群体中个体,采集血样进行布鲁氏菌抗体检测。同时,通过问卷调查和查阅资料等方式,分析布鲁氏菌病感染和传播风险。结果显示:全市羊布鲁氏菌病表观场群流行率为1.54%(95%CI:0.42%~3.91%),表观个体流行率为0.60%(95%CI:0.43%~0.80%);4个阳性群集中分布于长沙县和宁乡县;和以往监测数据相比,长沙市的羊群布鲁氏菌病流行率和人间发病率均呈下降趋势,说明前期的防治策略取得积极成效。总体来说,长沙市布鲁氏菌病流行率较低,疫情处于稳定控制状态,因而可以分区域逐步实现全市布鲁氏菌病净化。     

Influence of the root endophyte Piriformospora indica on the plant water relations,gas exchange and growth of Chenopodium quinoa at limited water availability

This study aimed to evaluate the ability of Piriformospora indica to colonize the root of Chenopodium quinoa and to verify whether this endosymbiont can improve the growth, performance and drought resistance of this species. The study delivered, for the first time, evidence for successful colonization of P. indica in quinoa. Hence, pot experiment was conducted in the greenhouse, where inoculated and non‐inoculated plants were subjected to ample (40%–50% WHC) and deficit (15%–20%WHC) irrigation treatments. Drought adversely influenced the plant growth, leading to decline the total plant biomass by 74%. This was linked to an impaired photosynthetic activity (caused by lower g_s and C_i/C_a ratio; stomatal limitation of photosynthesis) and a higher risk of ROS production (enhanced ETR/A_gross ratio). P. indica colonization improved quinoa plant growth, with total biomass increased by 8% (controls) and 76% (drought‐stressed plants), confirming the growth‐promoting activity of P. indica. Fungal colonization seems to diminish drought‐induced growth hindrance, likely, through an improved water balance, reflected by the higher leaf ψ_w and g_s. Additionally, stomatal limitation of photosynthesis was alleviated (indicated by enhanced C_i/C_a ratio and A_net), so that the threat of oxidative stress was minimized (decreased ETR/A_gross). These results infer that symbiosis with P. indica could negate some of the detrimental effects of drought on quinoa growth, a highly desired feature, in particular at low water availability.     

Evaluation of Cold Tolerance in NERICAs Compared with Japanese Standard Rice Varieties at the Reproductive Stage

New Rice for Africa (NERICA) is a general name for interspecific rice varieties derived from a cross between the high‐yielding Asian rice (Oryza sativa L.) between locally adapted African rice (Oryza glaberrima Steud.). Eight NERICAs were evaluated for cold tolerance (CT) at the reproductive stage and compared with their O. sativa parents and three Japanese standard rice varieties over 3 years. Cold tolerance was evaluated based on the filled grain ratio (FGR) after cold water irrigation. The FGR was greatly reduced by cold water irrigation. NERICA 1, 2 and 7 had higher FGR (51.9–57.9 %), while NERICA 6, 15 and 16 had lower FGR (6.2–14.5 %). NERICA 1, 2 and 7 were less affected by cold stress, with a 31 % mean reduction in FGR, while NERICA 6, 15 and 16 were greatly affected, with their FGRs being reduced by more than 80 %. NERICA 3 and 4 were moderately affected by cold stress, with about 45 % reduction rate in FGR. FGR significantly influenced the grain weights of the varieties with strong positive correlations (r = 0.83–0.91; P < 0.001), and thus, similar trends in grain weights were observed. Grain weights were reduced by 61.7–96.4 % under cold stress. NERICA 1, 2 and 7 showed significantly better performance than NERICA 3 and 4, while NERICA 6, 15 and 16 performed poorly under cold water irrigation. The Japanese varieties Koshihikari (very tolerant) and Ozora (moderately tolerant) were more affected by cold water irrigation than NERICA 1, 2 and 7. On the basis of the mean reduction rate (%) in FGR under cold stress, the varieties were classified as follows: NERICA 1, 2 and 7 as tolerant; NERICA 3 and 4 as moderately tolerant; and NERICA 6, 15 and 16 as susceptible to cold stress. However, NERICA 7 grain yields were lower under cold stress due to both greatly reduced number of panicles per plant and number of spikelets per panicle. Therefore, NERICA 1 and 2 are suitable candidates for production in the highland regions of East Africa and should be promoted for production.     

Copper‐Induced Oxidative Stress and Responses of the Antioxidant System in Roots of Medicago sativa

The effects of various copper (Cu) concentrations on the antioxidative system in the roots of Medicago sativa were explored. The results indicated that the Cu content of the roots reached a value of 854 μg g^?1 DW at 10 μm Cu and a value of 4415 μg g^?1 DW at 100 μm Cu, suggesting that M. sativa has better ability to tolerate and accumulate Cu than other Cu‐bioaccumulators, and is a potential plant for phytoremediation. Treatment with Cu resulted in a significant increment in the levels of H₂O₂, O₂˙^? and OH˙. The reduced form of ascorbate and glutathione reached a peak at 30 μm Cu, and was followed by a sharp depletion to a lower level than that of the control. In contrast, the levels of the oxidised forms of ascorbate and glutathione showed a progressive increment with increasing Cu concentrations, suggesting that the antioxidant system was unable to cope with Cu stress at higher Cu levels. Under the Cu concentrations tested, the activity of catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.6.4.2) increased at lower Cu concentrations, and then decreased, reaching a maximum at 30 μm of Cu for APX and GR, at 10 μm for CAT, whereas the activities of guaiacol peroxidase (POD, EC 1.11.1.7) were gradually increased with increasing Cu concentrations. PAGE analysis of superoxide dismutase (SOD, EC 1.1.5.1.1) revealed that one band is a Mn‐SOD and five bands are identified as Cu, Zn‐SOD, whereas Fe‐SOD isoforms were not found in the roots of alfalfa. Cu at 10–100 μm increased the intensity of constitutive isozymes of CAT, APX and POD, whereas it decreased the intensity of isozymes of glucose‐6‐phosphate dehydrogenase (G6PDH, EC 1.1.1.49) significantly. The activities of lipoxygenases (LOX, EC 1.13.11.12) were gradually augmented with increasing Cu concentrations, demonstrating that LOXs are probably involved in production of lipid hydroperoxides and superoxide anion. There was a continuous and pronounced enhancement in the activity of esterase (EST, EC 3.1.1.1) in roots treated with 10–30 Cu μm , whereas EST activity in roots exposed to above 30 μm Cu declined, suggesting that EST plays a protective role under lower Cu concentrations stress.     

The Situation for Quinoa and Its Production in Southern Bolivia: From Economic Success to Environmental Disaster

In Bolivia, one of the world’s most important centres of plant domestication, there is growing awareness of the value of native Andean crops, both for domestic consumption and for market sale – notably the virtually boom‐like consumer demand for quinoa around the world. The southern altiplano of Bolivia, south of Oruro, relies almost purely on the production of quinoa and breeding of llamas, which have also been selected as the two commodities of priority to the government to increase the income of the country. Presently, however, quinoa is facing increasing problems in production, owing to its increasing export market and price. The flat areas around the salt desert of the southern altiplano, previously characterized by natural vegetation fed by the llamas, are being increasingly sown with quinoa, hence transformed into deserts, because intensive cultivation methods make the soil loose its fertility. Possible solutions to these problems will require extensive efforts in the south, in addition to various strategies, which also include other parts of the Bolivian altiplano and a strengthened focus on other Andean crops.     

宁夏玉米营养成分近红外分析模型建立与应用

研究采集宁夏区内各市县(固原、海原、同心、中卫、中宁、永宁、平罗)抽取玉米样品120批,用近红外分析仪扫描定标样品集获得玉米近红外光谱图,利用偏最小二乘法建立模型,并分别经过无预处理、均值中心化、标准正态变量转换、一阶导数、标准正态变量转换结合去趋势校正(SNV+D)预处理光谱,获得水分、粗蛋白、粗脂肪、粗纤维预测模型,分别是经过MC、SNV+D、SNV+D、SNV+D光谱预处理后效果最好。预测决定系数R² _p分别为0.951、0.976、0.728、0.897,相对分析误差RPD除粗脂肪为2.62外,其他均大于3的近红外预测模型,通过预测模型验证集验证后,并对模型预测值与实测值进行U检验,结果为差异不显著(P>0.05)。该近红外预测模型对玉米中水分、粗蛋白、粗纤维具有较佳预测效果,粗脂肪的预测精度有待进一步提高。     

杏鲍菇多孢分离菌株ISSR、RAPD分子标记及体细胞不亲和性分析

通过杏鲍菇多孢分离菌株的ISSR、RAPD分子标记和体细胞不亲和性分析,体细胞不亲和性分析得出子代杏1、杏3、杏4与出发菌株湘杏98有拮抗线,杏1、杏2、杏3、杏4四株子代均有明显的拮抗线。16条ISSR引物和19条RAPD引物分别扩增出99、154个条带,多态性条带分别占48.48%、61.00%;相似系数变异范围分别为0.63~0.86、0.57~0.83。湘杏98、杏2、杏3在2种标记的聚类结果上存在差异。体细胞不亲和性分析从表型上(拮抗线有无)反应了菌株的遗传变异。RAPD标记遗传相似系数小于ISSR标记,表明ISSR标记更适合亲缘关系较近的种群间遗传多样性分析。     

Genome‐Wide Identification of MicroRNAs Responsive to High Temperature in Rice (Oryza sativa) by High‐Throughput Deep Sequencing

MicroRNAs (miRNAs) are known to play important roles in plant growth and stress response. Heat stress is a severe abiotic stresses by adversely affecting plant growth and yield. To identify heat‐responsive miRNAs at the genome‐wide level in rice (Oryza sativa), we constructed two small RNA libraries from young panicles treated or not with heat conditions. Ion torrent sequencing of the two libraries identified 294 known miRNAs and 539 novel miRNAs. Differential expression analysis showed that 26 miRNAs were downregulated and 21 miRNAs were upregulated in response to heat stress. Among them, five heat‐responsive miRNAs, including miR162b, miR529a‐p5, PC‐5P‐62245‐9, miR171b and miR169n, were validated by quantitative real‐time polymerase chain reaction. A total of 44 target genes of the differentially expressed miRNAs were predicted. These target genes are most significantly overrepresented in the cell growth process. The results demonstrated that rice miRNAs play critical roles in the heat stress response. This study opens up a new avenue for understanding the regulatory mechanisms of miRNAs involvement in the heat stress response in rice.     

氨基酸介导的TOR信号传导通路研究进展

TOR(target of rapamycin)是一种进化上十分保守的丝氨酸(Ser)/苏氨酸(Thr)蛋白激酶,可以感知营养状况、能量、生长因子等信号,进而调节细胞的生长、增殖和凋亡等生理进程.本文综述了TOR的上、下游信号传导通路及各种氨基酸对TOR信号传导通路的影响,为探讨氨基酸调控蛋白质合成的作用机制及建立精确...